https://hdl.handle.net/1721.1/34285 2026-04-04T06:51:53Z 2026-04-04T06:51:53Z Perez Gago, Cecilia Hansman, R. John https://hdl.handle.net/1721.1/164750 2026-02-06T03:00:48Z 2026-02-05T00:00:00Z

Human Factors Observations in Flightcrew Response to System Failure Events in Transport Category Aircraft from 2000 to 2024 Perez Gago, Cecilia; Hansman, R. John

2026-02-05T00:00:00Z Trávník, Marek Hansman, R. John https://hdl.handle.net/1721.1/164678 2026-02-01T03:01:19Z 2026-01-30T00:00:00Z

Operational Fuel Inefficiency in Cruise Flight: A Worldwide Geospatial Analysis Trávník, Marek; Hansman, R. John

2026-01-30T00:00:00Z Cezairli, Mina Hansman, R. John https://hdl.handle.net/1721.1/163229 2025-10-18T03:01:22Z 2025-10-18T00:00:00Z

Feasibility Analysis and Fuel Burn Benefits of Relaxing Constraints in High Altitude Cruise Cezairli, Mina; Hansman, R. John

2025-10-18T00:00:00Z Sharpe, Peter D. https://hdl.handle.net/1721.1/163228 2025-10-18T03:01:00Z 2025-10-18T00:00:00Z

Accelerating Practical Engineering Design Optimization with Computational Graph Transformations Sharpe, Peter D.

2025-10-18T00:00:00Z Courtin, Christopher B. Hansman, R. John https://hdl.handle.net/1721.1/163227 2025-10-18T03:01:06Z 2025-10-18T00:00:00Z

Performance, Stability and Control of Electric Short Takeoff and Landing Aircraft Courtin, Christopher B.; Hansman, R. John

2025-10-18T00:00:00Z Salgueiro, Sandro Hansman, R. John https://hdl.handle.net/1721.1/163226 2025-10-18T03:01:29Z 2025-10-17T00:00:00Z

INCREASING FLEXIBILITY IN THE DESIGN AND OPERATION OF INSTRUMENT FLIGHT PROCEDURES Salgueiro, Sandro; Hansman, R. John

2025-10-17T00:00:00Z Li, Clement Hansman, R. John https://hdl.handle.net/1721.1/163224 2025-10-18T03:01:25Z 2025-10-17T00:00:00Z

Hierarchical Behavior Models for Characterizing Trajectories within Terminal Airspace Li, Clement; Hansman, R. John

2025-10-17T00:00:00Z Perez Gago, Cecilia Hansman, R. John https://hdl.handle.net/1721.1/163221 2025-10-18T03:01:07Z 2025-10-17T00:00:00Z

Task 2 Technical Report Perez Gago, Cecilia; Hansman, R. John

2025-10-17T00:00:00Z Perez Gago, Cecilia Hansman, R. John https://hdl.handle.net/1721.1/163218 2025-10-18T03:01:08Z 2025-10-17T00:00:00Z

An Annotated Bibliography Perez Gago, Cecilia; Hansman, R. John

2025-10-17T00:00:00Z Wang, Z. Juju Hansman, R. John https://hdl.handle.net/1721.1/155311 2024-06-27T03:25:57Z 2024-06-26T00:00:00Z

Analysis of the Correlation of Aircraft Overflight Noise Metrics and Aircraft Visibility from the Surface Wang, Z. Juju; Hansman, R. John

2024-06-26T00:00:00Z Gaubatz, Julia C. Hansman, R. John https://hdl.handle.net/1721.1/153302 2024-01-11T03:05:43Z 2024-01-10T00:00:00Z

Design and Development of Stability and Control Systems for Small, Deployable Aircraft Gaubatz, Julia C.; Hansman, R. John

2024-01-10T00:00:00Z Mathesius, Kelly J. Hansman, R. John https://hdl.handle.net/1721.1/153219 2023-12-21T03:52:08Z 2023-12-20T00:00:00Z

Integrated Design of Solid Rocket Powered Vehicles Including Exhaust Plume Radiant Emission Mathesius, Kelly J.; Hansman, R. John

2023-12-20T00:00:00Z Trávník, Marek Hansman, R. John https://hdl.handle.net/1721.1/145197 2022-08-30T03:02:31Z 2022-08-30T00:00:00Z

A Data-Driven Approach for Predicting and Understanding Braking Conditions of Aircraft Landings Trávník, Marek; Hansman, R. John

2022-08-30T00:00:00Z Mahseredjian, Ara Huynh, Jacqueline Hansman, R. John https://hdl.handle.net/1721.1/144311 2022-08-12T03:29:27Z 2022-08-11T00:00:00Z

A Data-Driven Approach to Departure and Arrival Noise Abatement Flight Procedure Development Mahseredjian, Ara; Huynh, Jacqueline; Hansman, R. John

2022-08-11T00:00:00Z Jansson, Madeleine Hansman, R. John https://hdl.handle.net/1721.1/133212 2021-10-28T04:58:49Z 2021-10-27T00:00:00Z

Development of a Fast Method to Analyze Patterns in Airport Noise Jansson, Madeleine; Hansman, R. John

2021-10-27T00:00:00Z Odoni, Amedeo R. https://hdl.handle.net/1721.1/132655 2021-09-29T03:16:38Z 2021-09-28T00:00:00Z

A Review of Certain Aspects of the Slot Allocation Process at Level 3 Airports Under Regulation 95/93 Odoni, Amedeo R.

2021-09-28T00:00:00Z Hansman, R. John Salgueiro, Sandro Thomas, Jacqueline Li, Clement Jansson, Madeleine Mahseredjian, Ara Zimmer, Kevin https://hdl.handle.net/1721.1/131242 2021-09-09T03:00:46Z 2021-09-08T00:00:00Z

Block 2 Procedure Recommendations for Boston Logan Airport Community Noise Reduction Hansman, R. John; Salgueiro, Sandro; Thomas, Jacqueline; Li, Clement; Jansson, Madeleine; Mahseredjian, Ara; Zimmer, Kevin

2021-09-08T00:00:00Z Sharpe, Peter D. Hansman, R. John https://hdl.handle.net/1721.1/131194 2021-08-25T03:22:36Z 2021-08-24T00:00:00Z

AeroSandbox: A Differentiable Framework for Aircraft Design Optimization Sharpe, Peter D.; Hansman, R. John

2021-08-24T00:00:00Z Courtin, Christopher B. Mahseredjian, Ara Dewald, Annick J. Drela, Mark Hansman, R. John https://hdl.handle.net/1721.1/131146 2021-08-06T03:21:14Z 2021-08-05T00:00:00Z

A Performance Comparison of eSTOL and eVTOL Aircraft Courtin, Christopher B.; Mahseredjian, Ara; Dewald, Annick J.; Drela, Mark; Hansman, R. John

2021-08-05T00:00:00Z Cho, HongSeok Hansman, R. John https://hdl.handle.net/1721.1/128822 2020-12-13T03:03:01Z 2020-12-11T00:00:00Z

Operational Design Domain (ODD) Framework for Driver-Automation Systems Cho, HongSeok; Hansman, R. John

2020-12-11T00:00:00Z Thomas, Jacqueline Hansman, R. John https://hdl.handle.net/1721.1/126037 2020-07-02T03:00:43Z 2020-07-01T00:00:00Z

Evaluation of the Impact of Transport Jet Aircraft Approach and Departure Speed on Community Noise Thomas, Jacqueline; Hansman, R. John

2020-07-01T00:00:00Z Vernacchia, Matthew T. https://hdl.handle.net/1721.1/126036 2020-07-02T03:14:26Z 2020-07-01T00:00:00Z

Motor case configuration options for Firefly-class rocket propelled UAVs Vernacchia, Matthew T.

2020-07-01T00:00:00Z Thomas, Jacqueline https://hdl.handle.net/1721.1/125995 2020-07-31T09:52:47Z 2020-06-26T00:00:00Z

Systems Analysis of Community Noise Impacts of Advanced Flight Procedures for Conventional and Hybrid Electric Aircraft Thomas, Jacqueline Recent changes to aircraft approach and departure procedures enabled by more precise navigation technologies have created noise concentration problems for communities beneath flight tracks. There may be opportunities to reduce community noise impacts under these concentrated flight tracks through advanced operational approach and departure procedures and advanced aircraft technologies. A modeling method to assess their impacts must consider the contributions of aircraft engine and airframe noise sources as they vary with the position, thrust, velocity, and configuration of the aircraft during the flight procedure. The objective is to develop an analysis method to design, model, and assess the community noise reduction possibilities of advanced operational flight procedures performed by conventional aircraft and advanced procedures enabled by future aircraft concepts. An integrated analysis framework is developed that combines flight dynamics and noise source models to determine the community noise impacts of aircraft performing advanced operational approach and departure procedures. Aircraft noise due to the airframe and engine is modeled using an aircraft source noise module as each noise component varies throughout the flight procedure and requires internal engine performance states, the flight profile, and aircraft geometry. An aircraft performance module is used to obtain engine internal performance states and aircraft flight performance given the aircraft technology level. A force- balance-kinematics flight profile generation module converts the flight procedure definition into altitude, position, velocity, configuration, and thrust profiles given flight performance on a segment-by-segment basis. The system generates single-event surface noise grids that are combined with population census data to estimate population noise exposure for a given aircraft technology level and procedure. The framework was demonstrated for both advanced approach and departure procedures and advanced aircraft technologies. The advanced procedure concepts include modified speed and thrust departures as well as continuous descent, steep, and delayed deceleration approaches for conventional aircraft. The ability to model advanced aircraft technologies was demonstrated in the evaluation of using windmilling drag by hybrid electric aircraft on approach to allow the performance of steep and delayed deceleration approaches for noise reduction beyond the performance capability of standard gas-turbine aircraft.

2020-06-26T00:00:00Z Vascik, Parker D. Hansman, R. John https://hdl.handle.net/1721.1/125990 2021-05-06T13:28:24Z 2020-06-26T00:00:00Z

Allocation of Airspace Cutouts to Enable Procedurally Separated Small Aircraft Operations in Terminal Areas Vascik, Parker D.; Hansman, R. John The current air traffic control (ATC) system is human-centric and voice-based. As a result, separation minima, controller workload, and radio frequency limitations may restrict the number of emerging unmanned aircraft system (UAS) or urban air mobility (UAM) operations that can occur within congested airspace. Limited ATC capacity will be especially impactful for UAS or UAM operations in proximity to large airports. One concept to reduce ATC limitations is to re-allocate airspace to develop procedurally separated corridors or regions where UAS and UAM aircraft may operate without receiving conventional ATC services. The creation of such “airspace cutouts” currently enables hundreds of daily small aircraft and helicopter operations in major U.S. cities without contributing to ATC workload. This paper develops an approach to analytically identify terminal airspace that is procedurally segregated from large aircraft operations and may be appropriate for new airspace cutouts. The magnitude of the benefit of allocating airspace in this manner is demonstrated at three major airports and in the 34 largest metropolitan areas of the United States.

2020-06-26T00:00:00Z Vernacchia, Matthew T. Hansman, R. John https://hdl.handle.net/1721.1/125567 2020-05-29T03:01:12Z 2020-05-28T00:00:00Z

Development of low-thrust solid rocket motors for small, fast aircraft propulsion Vernacchia, Matthew T.; Hansman, R. John

2020-05-28T00:00:00Z Vascik, Parker D. https://hdl.handle.net/1721.1/123692 2020-02-01T03:07:07Z 2020-01-30T00:00:00Z

Systems Analysis of Urban Air Mobility Operational Scaling Vascik, Parker D.

2020-01-30T00:00:00Z Meijers, Nicolas P. Hansman, R. John https://hdl.handle.net/1721.1/123677 2020-01-25T03:21:47Z 2020-01-24T00:00:00Z

Data-Driven Predictive Analytics of Runway Occupancy Time for Improved Capacity at Airports Meijers, Nicolas P.; Hansman, R. John

2020-01-24T00:00:00Z Courtin, Christopher B. Hansman, R. John Drela, Mark https://hdl.handle.net/1721.1/123447 2021-05-06T13:26:55Z 2020-01-15T00:00:00Z

Flight Test Results of a Subscale Super-STOL Aircraft Courtin, Christopher B.; Hansman, R. John; Drela, Mark This paper presents the results from initial flight tests of a 30% scale demonstrator of a blown-wing SuperSTOL concept aircraft, intended for operation from extremely short runways of 100 ft or less. The subscale demonstrator is aimed at investigating the maximum achievable in-flight lift coefficients with the blown wing, as well as the control and handling qualities with a mostly conventional aircraft configuration with unblown control surfaces. With a relatively modest amount of blowing power - a static thrust/weight of 0.45 - the flight tests show that the blown wing SuperSTOL concept can generate high lift coefficients greater than 10 in flight. It was observed that reducing the size of the propeller enabled larger CL values to be achieved. In high-CL flight the roll control authority of conventional ailerons was found to be marginal, partly due to the low fight dynamic pressure and partly due to the local stall over the unblown part of the aileron. In the configuration tested most of the elevator deflection was consumed to obtain pitch trim at low speed. A finite rotation rate to takeoff attitude was found to significantly contribute to the ground roll distance.

2020-01-15T00:00:00Z Courtin, Christopher B. Hansman, R. John https://hdl.handle.net/1721.1/122042 2019-09-13T03:00:55Z 2019-09-05T00:00:00Z

AN ASSESSMENT OF ELECTRIC STOL AIRCRAFT Courtin, Christopher B.; Hansman, R. John Distributed electric propulsion (DEP) is an emerging set of technologies which enable new vehicle configurations by allowing the efficient distribution of many smaller propulsors around the airframe. One application of this technology is to greatly enhance the short takeoff and landing (STOL) capability of a fixed-wing aircraft. STOL aircraft may have advantages over vertical takeoff and land (VTOL) configurations being considered for urban passenger transport missions due to lower risk associated with the certification process and improved performance or reduced weight due to smaller required propulsion systems. To be useful for these missions, STOL vehicles require short-field performance competitive with vertical lift configurations. One pathway to achieving this is by placing many electric motors and propellers along the leading edge of the wing, an arrangement referred to as a DEP blown wing. This arrangement increases the effective lift of the wing through interaction of the propeller slipstream with the trailing edge flap. Previous blown wing concepts, based on large propellers or turbine engines, were mechanically complex and adopted only for specialized applications. A DEP blown wing offers a simpler and potentially more efficient way to enhance the high-lift capability of a wing, but the performance is not reliably predictable using existing theoretical or empirical methods. A wind tunnel test of a representative 2D blown wing section was undertaken, and section lift coefficient values up to 9 were measured at moderate power settings. The results of this wind tunnel testing were used to predict the takeoff and landing performance of reference vehicles with wing and power loading representative of modern GA aircraft. The results of this analysis suggest that a DEP blown wing may enable takeoff and landing ground rolls of less than 100 ft. Landing distance over a 50 ft obstacle is identified as the likely driver of runway requirements for a super-short takeoff and landing vehicle.

2019-09-05T00:00:00Z Courtin, Christopher B. Hansman, R. John https://hdl.handle.net/1721.1/122036 2019-11-21T03:05:51Z 2019-09-04T00:00:00Z

Model Development for a Comparison of VTOL and STOL Electric Aircraft Using Geometric Programming Courtin, Christopher B.; Hansman, R. John There is widespread interest in the use of electric aircraft for short missions in and around urban areas. Most of the vehicle configurations proposed for these missions are electric Vertical Takeoff and Landing (VTOL) configurations, due to perceived limitations on the available infrastructure. Several recent studies have proposed electric Short Takeoff and Landing (STOL) aircraft with externally blown flaps as viable alternatives for urban operations. One of the claimed benefits of STOL aircraft is increased mission performance (in terms of range, payload, or speed) compared to an VTOL aircraft of the same weight. This study discusses the development of the models necessary to investigates this claim for a variety of possible missions, available infrastructure sizes, and levels of technology. Preliminary mission spaces where STOL or VTOL aircraft are the most weight-efficient choice are identified. The analysis is done using geometric programming, a convex optimization framework that enables rapid design re-optimization over a broad mission space.

2019-09-04T00:00:00Z List, Alexander H. Hansman, R. John https://hdl.handle.net/1721.1/122033 2019-09-04T03:01:46Z 2019-09-03T00:00:00Z

Assessing Multi-rotor UAV Controllability in Low Altitude Fine-Scale Wind Fields List, Alexander H.; Hansman, R. John This study presents a means of assessing unmanned aerial vehicle (UAV) control in various environments using control margin. The metric gives an instantaneous measure of control authority and is defined by dividing required torque by maximum available torque. Required torque is the sum total of torque developed by a vehicle's rotors and residual terms representing the torque required to compensate for any remaining disturbances. The metric was demonstrated on a representative small quad-rotor UAV in real world and laboratory environments. Utilizing only rotor revolutions per second and inertial measurement unit information, the metric indicates degraded control in conditions consistent with loss of control. This metric may ultimately be useful in understanding the low level wind environment, for certification of vehicles, or for real-time monitoring of control authority.

2019-09-03T00:00:00Z Ennen, David Allroggen, Florian Malina, Robert https://hdl.handle.net/1721.1/121459 2019-07-02T03:08:03Z 2019-06-28T00:00:00Z

Non-stop versus connecting air services: Airfares, costs, and consumers’ willingness to pay Ennen, David; Allroggen, Florian; Malina, Robert Airlines provide both non-stop and connecting services. The airfare for each service type is determined largely by the willingness to pay (WTP) of passengers and the costs for airlines. This paper estimates the impact of itinerary characteristics such as number of stopovers, detour, layover time, and aircraft size on airfares using a novel demand and supply model. This model allows us to calculate both costs and markups for non-stop and connecting itineraries in U.S. domestic markets. We find that, on average, passengers have a higher WTP for nonstop flights and the WTP for connecting flights is driven particularly by the number of stopovers, in-flight time, and transfer time. As a result, we identify significant heterogeneity with regard to costs and mark-ups between markets. While in most U.S. domestic markets airlines incur higher costs for operating connecting routings, the indirect routing via a hub achieves lower costs in some markets, as the economies associated with the use of larger aircraft offset the costs of the stopover. Finally, we show that the presence of connecting services reduces fares for nonstop flights, in particular for itineraries with a longer market distance as detours and the significance of fixed costs associated with a stopover decrease.

2019-06-28T00:00:00Z Vascik, Parker D. Cho, Jungwoo Bulusu, Vishwanath Polishchuk, Valentin https://hdl.handle.net/1721.1/121275 2019-06-15T03:04:05Z 2019-06-14T00:00:00Z

A Geometric Approach Towards Airspace Assessment for Emerging Operations Vascik, Parker D.; Cho, Jungwoo; Bulusu, Vishwanath; Polishchuk, Valentin Emerging Urban Air Mobility (UAM)operators propose to introduce extensive flight networks into metropolitan airspace.However,this airspace currently contains complex legacy airspace constructs and flight operations that are perceived as safe, efficient, and generally acceptable to the overflown public. Hence, Air Traffic Management (ATM) concepts to support UAM may be constrained to cause little to no interference with these legacy operations. The identification of airspace that is non-interfering and potentially “available” to these new operators is therefore a critical first step to support UAM integration.This paper introduces a geometric airspace assessment approach that considers seven existing airspace constructs. Four hypothetical ATM scenarios are developed that prescribe different degrees of UAM integration. An alpha-shape topological method is refined to process geometrically complex airspace construct polygons over an expansive geographic area and develop 3D mappings of airspace availability.The approach is demonstrated in the San Francisco Bay Area and is readily extensible to other locations. It is envisioned to be useful in identification of viable takeoff and landing sites, evaluation of the sensitivity of airspace availability to separation or trajectory conformance requirements, and flight route design, throughput estimation and riskanalysis.

2019-06-14T00:00:00Z Mathesius, Kelly J. Hansman, R. John https://hdl.handle.net/1721.1/121214 2019-06-06T03:01:02Z 2019-06-05T00:00:00Z

Manufacturing Methods for a Solid Rocket Motor Propelling a Small, Fast Flight Vehicle Mathesius, Kelly J.; Hansman, R. John A gap exists in the design space for aircraft mass and speed: no flight vehicles with a mass of less than 10 kg and speed greater than 100 m/s are available. The small, fast "Firefly" flight vehicle is being developed to explore the capabilities and challenges for aircraft in this gap. The compact Firefly aircraft is configured around a long-endurance, end-burning solid rocket motor that provides 2-3 minutes of powered flight. Challenges exist for manufacturing solid rocket motors for small, fast aircraft such as Firefly. Achieving desired motor performance requires a void-free propellant grain and thermal liner and a strong propellant-to-liner bond. However, observations and tests following several motor manufacturing attempts have revealed voids in the propellant and liner and delamination at the propellant-to-liner interface. Manufacturing defects such as these have led to large increases in chamber pressure and thrust during a static fire test of a motor. This thesis describes the development and implementation of manufacturing methods for slow-burning, long endurance motors used in small, fast aircraft. Innovative tooling and rigorous procedures have been developed to help ensure the consistent production of a long-endurance solid rocket motor. Successful static firings of a test motor validate the effectiveness of many of the developed manufacturing methods.

2019-06-05T00:00:00Z Vascik, Parker D. Hansman, R. John https://hdl.handle.net/1721.1/121182 2019-06-01T03:06:24Z 2019-05-31T00:00:00Z

Assessing Integration Between Emerging and Conventional Operations in Urban Airspace Vascik, Parker D.; Hansman, R. John This paper investigates the use of low altitude airspace by conventional flight operations in proximity to the San Francisco, Boston, and Atlanta international airports. The purpose of the investigation is two-fold. First, the study presents an approach to develop lateral and vertical containment boundaries for arrival and departure flight trajectories. The boundaries describe the extent of the airspace actively used to support the flights. Second, the study develops containment boundaries for large transport aircraft operations at the three airports to demonstrate how these conventional operations may influence where and when emerging Unmanned Aircraft Systems (UAS) or Urban Air Mobility (UAM) networks may operate. 180 days of ASDE-X radar tracking data were analyzed to determine the location and traffic density of large transport aircraft, helicopters, and four other classes of operators. The flight trajectories for each operator class were sorted into arrivals, departures, and missed approaches to or from each runway. Containment boundaries were first developed for transport aircraft with greater than 100 passenger seats. Airspace that remained outside the containment boundary could potentially support simultaneous but non-interfering UAS or UAM operations. Variations in containment size due to airport-specific attributes were investigated. Containment boundary expansion to accommodate regional and commuter aircraft operations was assessed. Finally, airport access for UAM or UAS operators based upon conventional flight operations was considered.

2019-05-31T00:00:00Z Yu, Alison Y. Hansman, R. John https://hdl.handle.net/1721.1/121166 2019-05-23T03:00:39Z 2019-05-22T00:00:00Z

Aircraft Noise Modeling of Dispersed Flight Tracks and Metrics for Assessing Impacts Yu, Alison Y.; Hansman, R. John The implementation of Performance Based Navigation (PBN), such as Area Navigation (RNAV) and Required Navigation Performance (RNP), has led to aircraft being able to fly designed flight tracks very precisely. This has led to communities citing the concentration of aircraft along one flight track as a noise issue because of the frequent overflights above specific areas. In order to assess the impact of frequent overflights, metrics for understanding the annoyance mechanism were necessary. The metric Nx, which is a count of the number of overflights above the A-weighted maximum sound level (LA,max) of xdB during the day and (x-10)dB during the night, was investigated. The metric Nx required analysis of the LA,max noise level to count as an overflight, as well as the number of overflights that represented the annoyance threshold. N60 on a peak day with 50 overflights was shown to represent at least 80% of the complaint locations at BOS, MSP, LHR, and one runway at CLT. Alternatively peak day DNL is also shown to be a possible representative noise metric and will also be investigated. A noise metric representative of the impacts of frequent overflights allowed for communication of analysis results for possibilities for dispersed flight tracks. Important ways to communicate analysis results to stakeholders included: overall increase or decrease in population exposure to N60 on a peak day with 50 overflights, the change in the number of N60 overflights for the areas of impact, and presentation of the data that allowed stakeholders to understand the impact within the boundaries of their specific representative area. These tools will allow communities to understand the noise impacts of the procedures considered and will support the stakeholder decision processes.

2019-05-22T00:00:00Z Deaton, John L. Hansman, R. John https://hdl.handle.net/1721.1/121165 2019-05-21T03:00:45Z 2019-05-20T00:00:00Z

Investigating Collision Avoidance for Small UAS using Cooperative Surveillance and ACAS X Deaton, John L.; Hansman, R. John Small Unmanned Aircraft Systems (sUAS) have proliferated over the last decade. While these platforms offer many benefits to society, they pose a dangerous mid-air collision hazard. In order to safely integrate into airspace shared by other users, sUAS must be able to avoid collisions with manned aircraft. To better understand sUAS flight behavior and inform Collision Avoidance (CA) systems for sUAS, over 600 active UAS platforms were reviewed. The mean climb rate capability was 720 feet per minute (fpm) for all reviewed sUAS, which suggests that CA systems currently used by manned aircraft (which require 2,500 fpm climb capability) would be inappropriate for implementation on sUAS. Novel CA systems are therefore required. Next, to assess the feasibility of CA system equipage on sUAS, the Size, Weight, Power, and Cost (SWaP-C) of equipment necessary for CA systems were studied. It was determined that a complete CA system utilizing cooperative surveillance could weigh less than 70 grams and require less than 2 W of average input power. Because cooperative surveillance broadcasts from sUAS could overload the spectrum currently used to share aviation information, signal transmissions were simulated for a population of sUAS broadcasting alongside current users. While transmitting sUAS would quickly degrade performance on the busy 1090 MHz channel, the 978 MHz channel could potentially support about 1 transmitting sUAS per square kilometer if sUAS broadcast ADS-B signals at only 80 mW. Finally, close encounters between sUAS and manned aircraft were simulated in the Mode C Veil environment to evaluate threat resolution options used by different CA systems. Manned aircraft using existing CA systems to avoid sUAS would achieve extremely high levels of safety (risk ratios below 0.05) but would experience high rates of alerts. Furthermore, sUAS are so small that manned aircraft without CA systems would be unlikely to visually see and avoid them. Novel CA systems were modeled on sUAS and were able to avoid manned aircraft with currently-accepted levels of safety (risk ratios below 0.18) even with limited or no vertical maneuvering by using horizontal escape maneuvers (i.e. turns). Alerting rates for horizontal maneuvers were high but may be acceptable for use on sUAS. The new sUAS CA systems cooperated well with existing systems for manned aircraft and resulted in extremely low collision risk (risk ratios below 0.02) in encounters where manned aircraft and sUAS both took action to avoid collisions. Results therefore indicate that sUAS could utilize existing cooperative surveillance systems and prototype CA policies to mitigate close encounters with manned aircraft in Mode C Veils at safety levels that are currently accepted among manned aircraft.

2019-05-20T00:00:00Z Sng, Zheng Yang Hansman, R. John https://hdl.handle.net/1721.1/121164 2019-05-21T03:00:48Z 2019-05-20T00:00:00Z

A Petri Net Framework for the Representation and Analysis of Aircraft Turnaround Operations Sng, Zheng Yang; Hansman, R. John Aircraft turnaround operations is a key determinant of both airline and airport performance. Airlines incur both direct and indirect costs from poor on-time departure performance, particularly when these delays propagate through an airline’s schedule and additional resources have to be utilized for schedule recovery. As for airports, poor stand utilization due to excessive stand occupancy times can give rise to stand shortages and last-minute reallocations which disrupt operations across both terminal and airside. As such, optimization of aircraft turnaround operations provides opportunities for improvements at a systemic level. Petri Nets were chosen as the modelling tool as they possess features which can sufficiently account for both the complexity and uncertainty associated with aircraft turnarounds. Petri Nets models were first constructed to provide general representations for the turnaround operations of narrow-bodied B738 and wide-bodied A333 aircrafts. The Petri Nets were then adapted to make provisions for operational procedures specific to Changi Airport Singapore, the case study for this paper. The rationale for this 2-step process is to facilitate reusability of the proposed framework as the Petri Nets can be adapted to fit different contexts. After the Petri Nets were calibrated using empirical data, Monte Carlo simulations were performed. Critical path analysis was then conducted for characterization of existing operations. For B738, critical paths involving passenger services and fueling-related activities dominated. For A333, critical paths involving passenger services as well as fueling-related and catering-related activities dominated. Different modifications were then added to the Petri Nets and subsequently evaluated for their potential to reduce stand occupancy times through additional rounds of simulation. Different combinations of modifications involving automated aerobridge operations and removal of passenger deboarding as a precedent constraint for fueling-related and catering-related activities achieved noticeable reductions in stand occupancy times for B738 and A333. The potential reductions in stand occupancy times from improved scheduling outcomes were also analyzed.

2019-05-20T00:00:00Z Condé Rocha Murça, Mayara Hansman, R. John https://hdl.handle.net/1721.1/121155 2019-04-27T03:05:51Z 2019-04-26T00:00:00Z

Data-Driven Modeling of Air Traffic Flows for Advanced Air Traffic Management Condé Rocha Murça, Mayara; Hansman, R. John The Air Traffic Management (ATM) system enables air transportation by ensuring a safe and orderly air traffic flow. As the air transport demand has grown, ATM has become increasingly challenging, resulting in high levels of congestion, flight delays and environmental impacts. To sustain the industry growth foreseen and enable more efficient air travel, it is important to develop mechanisms for better understanding and predicting the air traffic flow behavior and performance in order to assist human decision-makers to deliver improved airspace design and traffic management solutions. This thesis presents a data-driven approach to modeling air traffic flows and analyzes its contribution to supporting system level ATM decision-making. A data analytics framework is proposed for high-fidelity characterization of air traffic flows from large-scale flight tracking data. The framework incorporates a multi-layer clustering analysis to extract spatiotemporal patterns in aircraft movement towards the identification of trajectory patterns and traffic flow patterns. The outcomes and potential impacts of this framework are demonstrated with a detailed characterization of terminal area traffic flows in three representative multi-airport (metroplex) systems of the global air transportation system: New York, Hong Kong and Sao Paulo. As a descriptive tool for systematic analysis of the flow behavior, the framework allows for cross-metroplex comparisons of terminal airspace design, utilization and traffic performance. Novel quantitative metrics are created to summarize metroplex efficiency, capacity and predictability. The results reveal several structural, operational and performance differences between the metroplexes analyzed and highlight varied action areas to improve air traffic operations at these systems. Finally, the knowledge derived from flight trajectory data analytics is leveraged to develop predictive and prescriptive models for metroplex configuration and capacity planning decision support. Supervised learning methods are used to create prediction models capable of translating weather forecasts into probabilistic forecasts of the metroplex traffic flow structure and airport capacity for strategic time horizons. To process these capacity forecasts and assist the design of traffic flow management strategies, a new optimization model for capacity allocation is developed. The proposed models are found to outperform currently used methods in predicting throughput performance at the New York airports. Moreover, when used to prescribe optimal Airport Acceptance Rates in Ground Delay Programs, an overall delay reduction of up to 9.7% is achieved.

2019-04-26T00:00:00Z Burton, Michael Hansman, R. John Tao, Tony Hoburg, Warren https://hdl.handle.net/1721.1/119900 2019-04-12T09:35:08Z 2019-01-10T00:00:00Z

Flight Test Report of the Jungle Hawk Owl Long-Endurance UAV Burton, Michael; Hansman, R. John; Tao, Tony; Hoburg, Warren

2019-01-10T00:00:00Z Vascik, Parker D. Hansman, R. John https://hdl.handle.net/1721.1/119874 2019-04-12T23:14:07Z 2019-01-08T00:00:00Z

Development of Vertiport Capacity Envelopes and Analysis of Their Sensitivity to Topological and Operational Factors Vascik, Parker D.; Hansman, R. John This study develops an Integer Programming (IP) approach to analytically estimate vertiport capacity envelopes. The approach is used to determine the sensitivity of vertiport capacity to the number and layout of touchdown and liftoff pads, taxiways, gates, and parking pads (i.e. the vertiport topology). The study also assesses the sensitivity of vertiport capacity to operational parameters including taxi time, turnaround time, pre-staged aircraft, and approach/departure procedure independence, among others. Findings indicate the importance of balancing the number of touchdown and liftoff pads with the number of gates to achieve maximum aircraft throughput per vertiport footprint. Furthermore, simultaneous paired arrivals or departures provide significant throughput gains without the need for fully independent approach and departure procedures. The methodology and findings introduced in this paper support the development of concepts of operation to maximize throughput for a given vertiport footprint and demand scenario. While throughput has been extensively researched for fixed-wing operations, little research has been dedicated to the operation of infrastructure for Vertical Takeoff and Landing (VTOL) aircraft. The emergence of new VTOL aircraft to conduct a potentially large number of urban air mobility operations creates a need to better understand the operation and throughput capacity of vertiports, especially in space constrained inner-city locations. This paper reviews numerous existing heliport designs to derive four topology classes of vertiport layouts. The IP formulation of vertiport operations is readily adapted to represent the infrastructure and operations of these layouts.

2019-01-08T00:00:00Z Li, Clement Hansman, R. John https://hdl.handle.net/1721.1/118439 2019-04-11T01:53:26Z 2018-10-11T00:00:00Z

Preliminary Development and Flight Trials of a Cruise Altitude and Speed Optimization Decision Support Tool Li, Clement; Hansman, R. John A cruise altitude and speed optimization decision support tool, based on the concept of a minimum cost altitude tunnel, was developed to aid flight crew and dispatcher situational awareness and decision-making in vertical trajectory planning in order to reduce fuel and time costs. As the optimal altitude for an aircraft changes with speed, weight, outside air temperature, and winds, flight crew decision-making can benefit from the calculation and display of the relative flight costs of possible trajectories. The concept of a minimum cost tunnel is introduced, and the decision support tool is presented. Four preliminary flight trials were conducted with a Boeing 777-200 and prototype decision support tool. The preliminary flight trials suggest that the decision support tool is useful and improves situational awareness and coordination between dispatcher and flight crew. The initial flight trials also indicated that flight crews would benefit from higher quality turbulence information, including synchronization of the turbulence information available to flight crews and dispatchers. The largest fuel savings observed for a flight from the preliminary flight trials was over 3800 lbs. Additionally, the flight trials suggest that the minimum cost tunnel would even be useful as a static image included as part of the flight plan to provide situational awareness and facilitate coordination with dispatchers.

2018-10-11T00:00:00Z Courtin, Christopher Hansman, R. John https://hdl.handle.net/1721.1/118438 2019-04-10T23:29:24Z 2018-10-11T00:00:00Z

Safety Considerations in Emerging Electric Aircraft Architectures Courtin, Christopher; Hansman, R. John Safety and certification considerations which impact the design of an emerging new class of small, electric aircraft were investigated. Based on an assessment of the different emerging aircraft designs, vehicles were grouped based on lifting and propulsive architecture. Likely certification pathways and the associated airworthiness requirements were investigated. Key hazards were identified, and were classified by severity for each architecture group. The key hazards identified were lithium-polymer battery thermal runaway and energy uncertainty, common mode power system failure, and vehicle automation failure. Mitigation strategies for each identified hazard were identified based on current technology and regulatory requirements. These mitigation strategies were assessed for different vehicle architectures. Aircraft with the ability to controllably glide or autorotate are shown to have lower certification risk.

2018-10-11T00:00:00Z Vascik, Parker D. Balakrishnan, Hamsa Hansman, R. John https://hdl.handle.net/1721.1/117686 2019-04-10T19:52:50Z 2018-09-10T00:00:00Z

Assessment of Air Traffic Control for Urban Air Mobility and Unmanned Systems Vascik, Parker D.; Balakrishnan, Hamsa; Hansman, R. John This paper assesses how the introduction of urban air mobility services and unmanned aircraft systems may challenge Air Traffic Control (ATC) in the United States and what opportunities exist to support these forthcoming operations. Four attributes unique to these emerging operations were identified that may challenge effective ATC. Each attribute concerned the scalability of current ATC systems to support a large number of new airspace users at low altitudes. Six potential operational limitations were identified that ATC may impose upon airspace users in an effort to manage increased traffic demand. The fundamental mechanisms that set the aircraft capacity of an airspace, considered to be a surrogate for ATC scalability, were determined. The influence of ATC system architecture, technologies, and operational factors on these mechanisms was diagramed. Finally, the ability of various new ATC approaches to support high density, low altitude operations were reviewed with respect to these mechanisms.

2018-09-10T00:00:00Z Courtin, Christopher Burton, Michael Butler, Patrick Yu, Alison Vascik, Parker D. Hansman, R. John https://hdl.handle.net/1721.1/116863 2019-04-12T17:24:02Z 2018-07-10T00:00:00Z

Feasibility Study of Short Takeoff and Landing Urban Air Mobility Vehicles Using Geometric Programming Courtin, Christopher; Burton, Michael; Butler, Patrick; Yu, Alison; Vascik, Parker D.; Hansman, R. John Electric Short Takeoff and Landing (eSTOL) vehicles are proposed as a path towards implementing an Urban Air Mobility (UAM) network that reduces critical vehicle certification risks and offers advantages in vehicle performance compared to the widely proposed Electric Vertical Takeoff and Landing (eVTOL) aircraft. An overview is given of the system constraints and key enabling technologies that must be incorporated into the design of the vehicle. The tradeoffs between vehicle performance and runway length are investigated using geometric programming, a robust optimization framework. Runway lengths as short as 100-300 ft are shown to be feasible, depending on the level of technology and the desired cruise speed. The tradeoffs between runway length and the potential to build new infrastructure in urban centers are investigated using Boston as a representative case study. The placement of some runways up to 600ft is shown to be possible in the urban center, with a significant increase in the number of potential locations for runways shorter than 300ft. Key challenges and risks to implementation are discussed.

2018-07-10T00:00:00Z Chappelle, Christine A. Li, Clement Vascik, Parker D. Hansman, R. John https://hdl.handle.net/1721.1/116861 2019-04-10T10:29:21Z 2018-07-10T00:00:00Z

Opportunities to Enhance Air Emergency Medical Service Scale through New Vehicles and Operations Chappelle, Christine A.; Li, Clement; Vascik, Parker D.; Hansman, R. John Air Emergency Medical Service (Air EMS) provides unique and important medical trans- port capabilities to society. Air EMS can move patients or live organs more rapidly than surface modes over long distances or congested areas. Air EMS also provides unparalleled access to accident scenes in regions where surface transportation is compromised such as in the backcountry or during disaster scenarios. However, despite these unique capabilities, Air EMS is currently provided to only a small minority of the most critical medical cases. This is due to the high historical cost and risk of airborne operations. Air EMS costs are driven primarily by the high level of availability required of these services and their low utilization. The elevated accident rate compared to other forms of aviation is in large part due to the operation of these services to and from off-field landing areas with unmarked and perhaps un- known obstacles. This research investigates opportunities to increase the number of Air EMS operations provided in a region by reducing the cost per operation and increasing the level of care. Significant recent investments in Urban Air Mobility (UAM) systems are maturing a new class of electric aircraft and automation technologies that may provide benefits to Air EMS operations. Furthermore, opportunities to deploy Air EMS assets as part of a UAM system to increase utilization and reduce costs through revenue management are also reviewed. Finally, potential pathways to leverage Air EMS as a proving ground and forcing function to overcome constraints in air traffic control and community acceptance for broader UAM services are discussed. The results of this study suggest that near-term electric aircraft are not expected to meet the requirements of the Air EMS mission and also provide little cost reduction potential for the industry. However, new operational models that leverage UAM markets and airline rev- enue management systems show promise to enhance Air EMS scale. Finally, flight automation technologies in development for UAM aircraft show potential to increase Air EMS safety.

2018-07-10T00:00:00Z Vascik, Parker Hansman, R. John https://hdl.handle.net/1721.1/116860 2019-04-12T17:24:02Z 2018-07-10T00:00:00Z

Scaling Constraints for Urban Air Mobility Operations: Air Traffic Control, Ground Infrastructure, and Noise Vascik, Parker; Hansman, R. John The scalability of the current air traffic control system, the availability of aviation ground infrastructure, and the acceptability of aircraft noise to local communities have been identified as three key operational constraints that may limit the implementation or growth of Urban Air Mobility (UAM) systems. This paper identifies the primary mechanisms through which each constraint emerges to limit the number of UAM operations in an area (i.e. the scale of the service). Technical, ecosystem, or operational factors that influence each of the mechanisms are also identified. Interdependencies between the constraints are shown. Potential approaches to reduce constraint severity through adjustments to the mechanisms are introduced. Finally, an effort is made to characterize the severity of each operational constraint as a function of the density of UAM operations in a region of interest. To this end, a measure of severity is proposed for each constraint. This measure is used to notionally display how the severity of the constraint responds to UAM scaling, and to identify scenarios where efforts to relieve the constraint are most effective. The overall purpose of this paper is to provide an abstraction of the workings of the key UAM operational constraints so that researchers, developers, and practitioners may guide their efforts to mitigation pathways that are most likely to increase achievable UAM system scale.

2018-07-10T00:00:00Z Jensen, Luke L. Hansman, R. John https://hdl.handle.net/1721.1/116741 2019-04-10T22:24:19Z 2018-07-03T00:00:00Z

Data-Driven Flight Procedure Simulation and Noise Analysis in a Large-Scale Air Transportation System Jensen, Luke L.; Hansman, R. John Aircraft noise is a growing source of community concern around airports. Despite the introduction of quieter aircraft, increased precision of onboard guidance systems has resulted in new noise impacts driven by overflight frequency effects. Noise issues present a potential barrier to the continued rollout of advanced operational procedures in the US. This thesis presents a data-driven approach to simulating and communicating noise effects in the flight procedure development and modernization process, with input from multiple stakeholders with varying objectives that are technical, operational, and political in nature. First, a system-level framework is introduced for developing novel noise-reducing arrival and departure flight procedures, clarifying the role of the analyst given diverse stakeholder objectives. The framework includes relationships between baseline impact assessment, community negotiation, iterative flight procedure development, and formal implementation processes. Variability in stakeholder objectives suggests a need to incorporate noise issues in conjunction with other key operational objectives as part of larger-scale US air transportation system modernization. As part of this framework development, an airport-level noise modeling method is developed to enable rapid exposure and impact analysis for system-level evaluation of advanced operational procedures. The modeling method and framework are demonstrated by evaluating potential benefits of specific advanced procedures at 35 major airports in the US National Airspace System, including Performance Based Navigation guidance and a speed-managed departure concept.

2018-07-03T00:00:00Z Vascik, Parker Hansman, R. John https://hdl.handle.net/1721.1/115343 2019-04-12T22:47:55Z 2018-05-11T00:00:00Z

Evaluation Of Key Operational Constraints Affecting On-Demand Mobility For Aviation In The Los Angeles Basin: Ground Infrastructure, Air Traffic Control And Noise Vascik, Parker; Hansman, R. John This paper investigated three key operational constraints anticipated to impact On-Demand Mobility for Aviation markets in the Los Angeles basin including: community acceptance issues resulting from aircraft noise, the availability of takeoff and landing areas, and the scalability of operations under Air Traffic Control. The analysis provided insight into the nature of each of these constraints and potential approaches to their mitigation. First, existing ground infrastructure in Los Angeles that may support ODM Aviation operations was identified. A variety of proposed techniques to increase the geographic distribution and throughput capacity of ODM Aviation infrastructure were also evaluated. Second, ASDE-X radar tracking data from the Los Angeles International Airport was reviewed to identify areas where it may be feasible to route future ODM operations due to the low volume of conventional operations. Potential opportunities and risks associated with supplementing air traffic control through novel low-altitude management concepts such as NASA's Unmanned Aircraft System Traffic Management (UTM) program were also investigated. Finally, the influence of aircraft noise on local communities’ acceptance of aircraft operations was discussed. Various pathways through which communities may limit or prohibit aircraft operations were reviewed.

2018-05-11T00:00:00Z Hansman, R. John Vascik, Parker https://hdl.handle.net/1721.1/115341 2019-04-10T23:52:51Z 2018-05-11T00:00:00Z

Constraint Identification In On-Demand Mobility For Aviation Through An Exploratory Case Study Of Los Angeles Hansman, R. John; Vascik, Parker On-Demand Mobility (ODM) for Aviation is an emerging concept that proposes to provide aircraft-based, point-to-point transportation to consumers within a metropolitan area. This paper explicitly identified key operational constraints facing ODM Aviation networks and assessed how new vehicles and technologies could mitigate or reduce the severity of these constraints. An exploratory case study was developed to evaluate hypothetical ODM Aviation services in Los Angeles and the greater Southern California region. Promising early adopter markets were identified based upon current commuting and wealth patterns. A concept of operations (ConOps) was proposed for twelve reference missions that serviced a representative subset of these markets. Review of the reference missions provided a holistic impression of the potential implementation challenges facing an ODM Aviation network in a United States metropolitan region. Five key operational constraints were identified that may inhibit the near or far-term implementation of ODM Aviation operations. The constraints identified include: aircraft noise and community acceptance, the availability of ground infrastructure, aircraft interaction with air traffic control, community access to takeoff and landing areas, and the flight density achievable in uncontrolled airspace. Furthermore, three issues were identified including electric aircraft operating standards and certifications, all-weather operational capabilities, and ODM aircraft interaction with unmanned aircraft systems.

2018-05-11T00:00:00Z Hansman, R. John Jensen, Luke Thomas, Jacqueline O’Neill, Greg Yu, Alison https://hdl.handle.net/1721.1/114038 2019-04-12T09:03:11Z 2018-03-07T00:00:00Z

Block 1 Procedure Recommendations for Logan Airport Community Noise Reduction Hansman, R. John; Jensen, Luke; Thomas, Jacqueline; O’Neill, Greg; Yu, Alison Recent developments in navigation and surveillance technology have enabled new high-precision approach and departure operational procedures using GPS and Required Navigation Performance (RNP) standards. These procedures have proven effective for reducing fuel consumption and streamlining some aspects of air traffic control. However, flight tracks that were previously dispersed over wide areas due to less precise navigation or ATC vectoring are more concentrated on specific published tracks with effects on underlying communities. This study is an initial investigation to identify potential modifications to approach and departure procedures at Boston Logan International Airport (BOS) which would reduce community noise impact in areas which experience flight track concentration. Potential procedure modifications were separated into two sequential “Blocks”. Block 1 procedures were characterized by clear predicted noise benefits, limited operational/technical barriers and a lack of equity issues. Block 2 procedures exhibit greater complexity due to potential operational and technical barriers as well as equity issues (defined as noise redistribution between communities for the purposes of this study). This report presents recommendations for an initial set of Block 1 procedures. Continued analysis and community outreach will inform the identification and development of Block 2 procedures. RNAV procedures were implemented at BOS between 2012 and 2013. Candidate approach and departure modifications were first identified based on an analysis of historical flight track densities over the communities surrounding BOS before and after the implementation of new RNAV procedures coupled with noise complaint records and US Census population data. Potential procedure modifications were considered for each identified arrival and departure runway including: lateral flight track adjustment to avoid noise-sensitive areas, vertical trajectory modifications including speed, thrust or configuration management as well as techniques to reintroduce dispersion into flight trajectories. The technical recommendations presented in this report are not developed to an implementation-ready stage. Rather, the work completed to date represents a preliminary feasibility analysis for each recommended procedure. Prior to implementation of any of these recommendations, the FAA will need to execute internal verification and validation processes. Modifications to the recommended procedures may be required. The noise-reduction objectives for each procedure should be retained in any necessary procedure refinements. Procedure modification options were assigned to Block 1 or Block 2 based on a preliminary evaluation of noise reduction potential, operational/technical feasibility and potential equity issues. Some candidate procedures were rejected due to safety concerns or lack of noise benefits. The noise analysis compared the proposed modification with current procedures on a single-event basis. Noise contours and corresponding population exposures were calculated for the maximum noise level (LMAX) and Sound Exposure Level (SEL) metrics. The technical feasibility analysis included an examination of flight safety, aircraft performance, navigation and flight management system (FMS) limitations, pilot workload, ATC workload, and procedure design criteria. The process of procedure identification and refinement was informed by outreach to impacted stakeholders including community representatives, FAA regional and national offices, air traffic control (ATC) managers and specialists, airline technical pilots, and public officials.

2018-03-07T00:00:00Z Cho, HongSeok, R. John Hansman https://hdl.handle.net/1721.1/113881 2019-04-11T10:20:13Z 2018-02-26T00:00:00Z

Framework for Understanding the Driver's Trust in Automation and Its Implications on Driver's Decision and Behavior Cho, HongSeok, R. John Hansman The aim of this paper is to understand how designs of the automated driving system influence the driver's automation use decisions, and to provide design recommendations for SAE level 2 or 3 automated driving systems that would promote appropriate decisions of the driver. A risk-based framework, "decision matrix" is developed to represent the driver's decisions in terms of two variables: 1) perceived reliability of the automation, and 2) perceived consequence of the automation's potential unreliable behavior. Each block of the matrix represents a level of the perceived risk and an accompanying automation use decision of the driver; 1) use, 2) use with monitoring, and 2) do not use. Having the decision matrix at the core, an overall driver-automation system architecture is developed in order to describe how the driver makes a cognitive assessment of the observable states to evaluate the two decision matrix variables. The architecture also includes a learning process by which the driver develops and evolves his/her mental model based on the experience. The architecture is used to identify potentially inappropriate decisions of the driver as a result of the inaccurate evaluations of either the automation reliability or the consequences, or both. The framework suggests various methods (e.g. minimum performance of the automation, limiting automation use, information display and interface design, and training) which manufacturers can design to support the driver in learning of the automation's limitations and thus making appropriate evaluations of the decision variables. As a next step, potential designs of these methods to promote appropriate automation use decisions will be evaluated to determine the effectiveness of the methods.

2018-02-26T00:00:00Z Abel, Brandon Hansman, R. John https://hdl.handle.net/1721.1/111948 2019-04-11T01:23:17Z 2017-10-18T00:00:00Z

The Causes and Consequences of Divergence Between the Air Traffic Controller State Awareness and Actual System State Abel, Brandon; Hansman, R. John Divergence is an inconsistency between the human’s system state awareness and the actual system state. This research investigated divergence potential in air traffic controllers and identified controller divergence causes and consequences. Based on this investigation, approaches to minimize controller divergence and its consequences were identified for current air traffic control systems and future systems where unmanned aircraft will be integrated. Prior studies identified pilot divergence as a factor in several recent aircraft accidents and could be a factor for controllers. The future addition of unmanned aircraft in national airspace is a significant change which will affect the pilot and controller relationship and presents an opportunity to consider divergence before procedures are developed. To understand how to minimize divergence and its consequences, this research developed a divergence cause and consequence framework and a cognitive process framework. The cause and consequence framework was developed using established risk analysis methods. The cognitive process framework was developed using established cognitive process and human error approaches. This research refined these frameworks and demonstrated their utility in an investigation of historical air traffic control accidents. They were then used to identify divergence vulnerabilities in a future unmanned aircraft-integrated national airspace. Air traffic control cases were analyzed between 2011 and 2015 using the framework to understand causes and consequences of controller divergence. Twenty-seven (sixty-four percent) of these cases contained controller divergence contributing to the hazardous consequence. Although divergence causes and states varied, the most common event sequence included a diverged controller inducing an aircraft-to-aircraft conflict. These cases provided insight for system mitigations to reduce divergence causes and the consequentiality should it occur. The potential emergence of controller divergence with the integration of unmanned aircraft in national airspace was then investigated. Field studies of controllers experienced managing unmanned aircraft identified important differences between manned and unmanned aircraft. The framework was then used to analyze these potential divergence vulnerabilities. Observables, specifically intent, appear more challenging to perceive yet crucial for controller projection of unmanned aircraft position due to their lack of onboard human perception, lost link, and automated operations. Hazardous consequences may be more likely due to the inability for unmanned aircraft to provide mitigations.

2017-10-18T00:00:00Z Brenner, Morrisa A. Hansman, R. John https://hdl.handle.net/1721.1/110791 2019-04-10T15:57:31Z 2017-07-20T00:00:00Z

Comparison of Methods for Evaluating Impacts of Aviation Noise on Communities Brenner, Morrisa A.; Hansman, R. John Community opposition to the noise concentration from precise NextGen Performance-Based Navigation (PBN) aircraft arrival and departure procedures poses a significant threat to the future of these procedures in the U.S. National Airspace System. A substantial number of complaints concerning airport noise come from locations outside the 65dB Day-Night Level (DNL) contour considered the significant noise exposure threshold in U.S. federal regulation. This indicates that this threshold does not sufficiently capture areas that experience annoyance related to more concentrated, lower level overflight noise at distances farther from the airport. This thesis assesses the effectiveness by which different noise analysis methods capture the locations of these airport noise complaints through examination of the noise exposure for three representative scenarios at Boston Logan International Airport using DNL and number of overflights above a noise threshold (Nabove) metrics. The three scenarios examined include the standard noise analysis methodology scenario (annual average day) as well as a day of heavy usage of a noise-sensitive runway (33L for departures), and a scenario representing a peak hour of departures on this runway. The results indicate that the 33L peak day scenario does a better job of capturing a substantial fraction of the complainants sensitive to the 33L departure trajectories (66%-87% at the 45dB-50dB DNL thresholds) than the standard annual average day scenario. Results for the 33L peak day scenario indicate that the Nabove metric is also effective at capturing noise complaints at the 60dB day/50dB night noise threshold at exposure rates in the 25-50 overflight range (78%-84% complainant capture).

2017-07-20T00:00:00Z Brooks, Callen Hansman, R. John https://hdl.handle.net/1721.1/110790 2019-04-11T12:01:14Z 2017-07-20T00:00:00Z

Modeling the Effects of Aircraft Flight Track Variability on Community Noise Exposure Brooks, Callen; Hansman, R. John The implementation of Performance Based Navigation (PBN) routes across the National Airspace System (NAS) has caused a significant concentration of flight tracks. This flight track concentration also creates a concentration of noise impacts on the communities surrounding airports, which has led to an increase in noise complaints at many airports that have implemented these routes. In order to understand these changes in noise, and to design procedures that could help mitigate any negative effects, it is important to have modeling tools capable of capturing the noise impacts of flight track variability. This thesis develops a model for this purpose. First, twenty days of radar flight trajectory data from 2015 and 2016 at Boston Logan International Airport (KBOS) is used to quantify the observed distributions of variability in speed, altitude, and lateral track position. It is shown that altitude and speed variability have relatively small impacts on noise, but that the impacts of observed lateral variability are significant. Using this information, a physics-based model is developed to capture the noise impacts of lateral flight track variability. This tool is then used to model several example scenarios. First, the changes in noise due to pre- and post-PBN procedures are examined for KBOS Runway 33L departures. Next, a hypothetical procedure is designed to intentionally introduce lateral dispersion to KBOS Runway 33L departures. Finally, the tool is used to rapidly model noise impacts on due to both arrival and departure operations on all runways at KBOS. The model is shown to reduce computational expense by 1-2 order of magnitude relative to traditional methods. The results of these example analyses show that increased lateral dispersion causes a significant noise reduction at higher noise levels directly below the flight track at the cost of wider contours at lower noise levels. Because of this, any decision to add or remove flight track lateral dispersion has highly localized impacts that depend on the geometry of the route and the population of the surrounding area, and thus must be closely analyzed on an individual basis.

2017-07-20T00:00:00Z Salgueiro, Sandro https://hdl.handle.net/1721.1/109301 2019-04-11T01:21:08Z 2017-05-23T00:00:00Z

Analysis of Approach Stability and Challenges in Operational Implementation of RNP Approach Procedures Salgueiro, Sandro Required Navigation Performance (RNP) instrument procedures guarantee high levels of navigation precision through highly accurate navigation sources (e.g. GPS) and real-time monitoring of position estimation accuracy. In recent years, the Federal Aviation Administration (FAA) has developed and published public RNP approach procedures at airports across the country. These RNP procedures offer unique capabilities such as curved segments (radius-to-fix, or RF legs), narrow containment areas, and constant descent profiles that are not seen combined in other categories of instrument approaches. Because of these capabilities, RNP approaches are regarded as highly flexible procedures that can be designed to meet specific stakeholder requirements (e.g. lower minimums in mountainous areas, minimizing fuel burn during approach, avoiding flight over populated areas for noise abatement, etc.) at the airport level. Among the various proposed benefits of RNP approaches, this study analyzed potential safety benefits related to improvements in approach stability. In total, 11,062 individual approaches at four airports were analyzed using radar (ASDE-X) data, of which 364 (3.29%) were identified as RNP procedures. Of all approaches analyzed, two non-RNP cases were identified as unsafe, while there were no unsafe RNP cases. However, due to the relatively low number of RNP approaches observed, no statistically significant evidence of improved stability on RNP approaches was found. Given the low utilization of RNP approach procedures found from radar data, further work was done to identify barriers to operational use of these procedures and to investigate strategies to accelerate the adoption of RNP across the National Airspace System (NAS). Potential factors driving the low utilization of RNP procedures were found to be the low levels of equipage and operational approval among air carriers, and difficulties in air traffic management stemming from mixed equipage operations.

2017-05-23T00:00:00Z Kolos-Lakatos, Tamas Hansman, R. John https://hdl.handle.net/1721.1/108355 2019-04-12T19:24:07Z 2017-04-21T00:00:00Z

A System Level Study of New Wake Turbulence Separation Concepts and Their Impact on Airport Capacity Kolos-Lakatos, Tamas; Hansman, R. John The air transportation industry continues to grow worldwide, but demand is often limited by available airspace and airport capacity. This thesis focuses on evaluating new air traffic procedures: specifically, new and emerging wake turbulence separation rules that could potentially increase runway capacity based on today’s knowledge of wake vortex turbulence and technological capabilities. While legacy wake separation rules establish aircraft-classes based on weight of aircraft, these new separation rules can define separation standards by considering other aircraft parameters and dynamic wind conditions. A fast-time runway system model is developed for studying these wake separation rules, using Monte-Carlo simulations, to provide accurate and realistic runway capacity estimates based on the randomness of arrival and departure operations. A total of nine new proposed wake separation rules are analyzed in detail, which include both distance-based and time-based methods, as well as static and dynamic concepts. Seven of the busiest and most delayed U.S. airports are selected as case studies for the illustration of runway capacity benefits enabled by these new wake separation rules: Boston (BOS), New York J.F. Kennedy (JFK), New York LaGuardia (LGA), Newark (EWR), San Francisco (SFO), Los Angeles (LAX), and Chicago O’Hare (ORD). For a detailed capacity analysis, the new wake separation rules are tested under the most constraining runway configurations at each of these airports. The results indicate that increasing the number of aircraft wake categories can increase runway capacity, but the added benefits become smaller with each new category added. A five-or six-category wake separation system can capture most of the runway capacity that can be achieved with a static pair-wise system. Additionally, shifting wake category boundaries between airports as a function of local fleet mix can provide additional runway capacity benefits, meaning that airport specific wake separation rules can increase capacity over a universal separation rule system. Among the new wake separation rules, the results indicate that reducing wake separations further from current minimum separations (separation values of 2NM or less) can shift the operational bottleneck from the approach path to the runway, as runway occupancy time becomes the limiting factor for inter-arrival separations. The findings from the time-based separation rule demonstrate that switching from distance-based separations to time-based separations in strong headwind conditions can recover significant lost capacity. Time-based separation rules can be of great value 4 to increase operational reliability and capacity predictability at airports in all weather conditions. Moreover, the results also indicate that a reduction in minimum separations enabled by dynamic wind and aircraft information can offer marginal runway capacity benefits over the capacity enabled by static pair-wise wake separations, as more and more aircraft pairs become limited by runway occupancy time. Therefore, a joint effort is needed for reducing both wake separations and runway occupancy in order to accommodate future air traffic demand.

2017-04-21T00:00:00Z Vascik, Parker Hansman, R. John https://hdl.handle.net/1721.1/106937 2019-04-10T23:21:12Z 2017-02-15T00:00:00Z

Systems-Level Analysis of On Demand Mobility for Aviation Vascik, Parker; Hansman, R. John On Demand Mobility (ODM) is an emerging transportation concept that leverages pervasive telecommunication connectivity to enable the real-time matching of consumers with transportation service providers. Having experienced rapid adoption in ground transportation markets, numerous entities are now investigating opportunities to provide aircraft-based ODM within metropolitan areas. Previous research efforts have focused primarily on the technical capabilities of novel electric propulsion aircraft and sought to characterize the market potential for these vehicles. This thesis complements these initial efforts by adopting a broad view of anticipated aircraft-based ODM services to identify operational constraints and evaluate near and far-term mitigation opportunities. A systems-level analysis was used to capture interdisciplinary influence factors such as limitations placed on ODM networks as a result of air traffic control, ground infrastructure integration, network load balancing, unmanned aircraft interaction and community noise, among others. The holistic considerations of this analysis extend beyond the traditional conceptual design disciplines of engineering and business to include evaluative perspective from the legal, policy, urban planning and sustainability domains. The first order, systems-level analysis approach for early-phase conceptual design developed in this thesis was applied to a case study in Los Angeles. Promising markets were identified based upon current commuting and wealth patterns. A notional concept of operations was then applied to twelve reference missions within these markets. Scrutiny of these missions revealed a variety of operational challenges from which five preeminent constraints were derived. These constraints may limit or prohibit ODM aircraft operations and include ground infrastructure availability, aircraft noise emissions and air traffic control scalability. Furthermore, significant legal and policy challenges were identified related to low altitude flight, environmental impacts and community acceptance. Findings from this thesis may support the ODM community to develop a system architecting plan that directs technology investments, stakeholder negotiations and network implementation so as to overcome the identified constraints and avoid or internalize negative externalities.

2017-02-15T00:00:00Z Thomas, Jacqueline Hansman, R. John https://hdl.handle.net/1721.1/106874 2019-04-12T22:32:09Z 2017-02-06T00:00:00Z

Modeling Performance and Noise of Advanced Operational Procedures for Current and Future Aircraft Thomas, Jacqueline; Hansman, R. John Increasing concerns regarding aircraft noise has encouraged the push to reduce noise via operational adjustments. The objective here is thus to expand analysis capabilities to enable modeling of the impact on aircraft noise due to advanced operational approach procedures, such as delayed deceleration approaches and thrust cutback scheduling on takeoff, for both current and future aircraft designs. Current industry standard noise models rely on flight test data interpolation and do not fully capture noise impacts from airframe configuration or advanced operational techniques. This is critical for noise assessment because airframe noise becomes a significant factor relative to the low thrust levels characteristic of advanced operational approaches. This method also limits the ability to assess new aircraft designs. Therefore, a new method combining aircraft sizing and performance tools with NASA’s Aircraft NOise Prediction Program (ANOPP) has been developed to capture those noise impacts. ANOPP is used because of its capability of computing noise received at ground observers due to both engines and airframe of aircraft flying any flight procedure. Inputs into ANOPP are the aircraft geometry, the flight procedure, and the engine performance during the flight procedure. The Transport Aircraft System OPTimization (TASOPT) model is used to compute the engine performance inputs into ANOPP via first principles, physics-based methods. A separate tool was developed to compute the specifics of the flight procedure (max glide slope obtainable for a particular velocity and configuration, required thrust levels, etc.) based on drag polar supplied either by the Base of Aircraft Data (BADA 4) for current aircraft or by TASOPT for new aircraft. Benefits of this modeling framework include the flexibility in the aircraft and procedure analyzed and the ability to predict the noise of future aircraft configurations without relying on existing data. Both the noise impacts of a sample advanced operational flight procedure and in a future aircraft fleet have been assessed with this model. Next steps include further use of this model to evaluate the noise benefits or detriments of advanced operational approaches.

2017-02-06T00:00:00Z Rabe, Matthew Hansman, R. John https://hdl.handle.net/1721.1/106140 2019-04-11T00:07:04Z 2016-12-27T00:00:00Z

Understanding the Effect of Cognitive Reference Frames on Unmanned Aircraft Operations Rabe, Matthew; Hansman, R. John As an ever-greater share of our national military airborne resources transition from manned to unmanned aircraft (UA) the issues associated with unmanned aircraft operations become more and more important. This study seeks to understand the difficulties associated with controlling both the unmanned aircraft and an onboard video sensor. Traditional unmanned aircraft involve multiple operators controlling multiple control displays that are often oriented on misaligned reference frames. One example unmanned aircraft mission includes a target described on a north-up reference frame, such as a map. The pilot plans a flight path, to this target, on a north-up map, but controls the aircraft along that flight path using an aircraft-view reference frame that offers a forward-looking cockpit view. Finally, the sensor operator controls the sensor to point at the target area using a sensor-view reference frame that offers a sensor viewfinder perspective. Any unmanned aircraft operator or team of operators is required to manage tasks across these multiple reference frames (north-up, aircraft-view, and sensor-view). This study investigated several display design techniques that had the potential to reduce the cognitive burden associated with correlating information from multiple reference frames. Orientation aids, reference frame alignment, display integration, and reduced display redundancy were all evaluated with human subject simulator experiments. During four separate experiments, a total of 80 subjects were asked to complete a series of representative unmanned aircraft operational tasks involving target acquisition, imagery orientation, target tracking, and flight path control. A simulator was developed to support this effort and allow for modification of display characteristics. Over all four experiments the reference frame alignment technique reduced basic orientation time and improved target acquisition time along with other performance and workload measures. The currently accepted practice of placing an orientation aid, such as a north arrow, on the displayed sensor video was only significant on the basic imagery orientation task and did not have a significant impact on the more involved target acquisition task. This research introduced a potential benefit of reference frame alignment on unmanned aircraft operations.

2016-12-27T00:00:00Z Bachwich, Alexander Wittman, Michael https://hdl.handle.net/1721.1/104869 2019-04-10T15:19:13Z 2016-10-19T00:00:00Z

The Emergence and Effects of the Ultra-Low Cost Carrier (ULCC) Business Model in the U.S. Airline Industry Bachwich, Alexander; Wittman, Michael The effects of “low-cost carriers” (LCCs) such as Southwest Airlines and JetBlue Airways on the competitive landscape of the U.S. airline industry have been thoroughly documented in the academic literature and the popular press. However, the more recent emergence of another distinct airline business model—the “ultra-low-cost carrier” (ULCC)—has received considerably less attention. By focusing on cost efficiencies and unbundled service offerings, the ULCCs have been able to undercut the fares of both traditional network and low-cost carriers in the markets they serve. In this paper, we conduct an analysis of ULCCs in the U.S. aviation industry and demonstrate how these carriers’ business models, costs, and effects on air transportation markets differ from those of the traditional LCCs. We first describe the factors that have enabled ULCCs to achieve a cost advantage over traditional LCCs and network legacy carriers. Then, using econometric models, we examine the effects of ULCC and LCC presence, entry, and exit on base airfares in 3,004 U.S. air transportation markets from 2010 – 2015. We find that in 2015, ULCC presence in a market was associated with market base fares 21% lower than average, as compared to an 8% average reduction for LCC presence. We also find that while ULCC and LCC entry both result in a 14% average reduction in fares one year after entry, ULCCs are three times as likely to abandon a market within two years of entry than are the LCCs. The results suggest that the ULCCs represent a distinct business model from traditional LCCs and that as the ULCCs grow, they will continue to play a unique and increasingly important role in the U.S. airline industry.

2016-10-19T00:00:00Z Tran, Henry Hansman, R. John https://hdl.handle.net/1721.1/102659 2019-04-10T19:47:30Z 2016-05-24T00:00:00Z

Fuel Benefit from Optimal Trajectory Assignment on the North Atlantic Tracks Tran, Henry; Hansman, R. John The North Atlantic Tracks represent one of the highest density international traffic regions in the world. Due to the lack of high-resolution radar coverage over this region, the tracks are subject to more restrictive operational constraints than flights over the continental U.S. Recent initiatives to increase surveillance over the North Atlantic has motivated studies on the total benefit potential for increased surveillance over the tracks. One of the benefits of increased surveillance is increased accessibility of optimal altitude and speed operations over the track system. For a sample of 4033 flights over 12 days from 2014-2015, a fuel burn analysis was performed that calculates the fuel burn from optimal altitude, optimal speed and optimal track trajectories over the North Atlantic Tracks. These results were compared with calculated as-flown fuel burn in order to determine the benefit potential from optimal trajectories. Operation at optimal altitude and speed increased this benefit to 2.83% reduction potential in average fuel burn. Operation at optimal altitude alone, however, reduces the benefit potential to 1.24% reduction in average fuel burn. Optimal track assignment allows for a 3.20% reduction in average fuel burn. For the sample data, 45.1% of flights were unable to access their optimal altitude and speed due to separation requirements. Reduced separation up to 5 nautical miles can decrease the number of conflicts to 14.0%. Reducing the separation requirements both longitudinally and laterally can allow for increased accessibility of optimal altitudes, speeds and track configurations. Pilot decision support tools that increase awareness of aircraft fuel performance by integrating optimal altitude and speed configurations can also reduce aircraft fuel burn. The utility of such a tool is evaluated through a survey on pilot-decision making.

2016-05-24T00:00:00Z Silva, Sathya Hansman, R. John https://hdl.handle.net/1721.1/102320 2019-04-10T19:43:50Z 2016-04-28T00:00:00Z

Divergence Between the Human State Assumption and Actual Aircraft System State Silva, Sathya; Hansman, R. John Divergence is defined in this thesis as an inconsistency between the human operator’s assumption of the system state and the actual state of the system, which is substantial enough to have consequential effects on the outcome of the situation. The purpose of this thesis is to explore the concept of divergence and develop a framework that can be used to identify the consequential causes of divergence in cases involving human-system interaction. Many recent aircraft accidents involve divergence between the crew state assumption and the actual system state. As aircraft systems and automation become more complex, it’s possible that the consequential effects of divergence, illustrated by these accidents, could become more prevalent due to the correspondingly more complex understanding that may be required by the crew to effectively operate the aircraft. Divergence was explored as a concept by (1) understanding the previous literature related to divergence such as work on human error, human information processing, situation awareness, and mode awareness (2) developing a framework that can be used to understand possible causes of divergence, (3) illustrating use of the framework with accident case studies, and (4) discussing the implications of the findings of the case study analysis of divergence. Human information processing of divergence was developed using the established human information processing literature including Wickens (1992), Endsley (1995), and Reason (1990). The framework highlighted the inputs to the human and represented human processing of this information in relation to formation of a state assumption. The process model was used to identify potential causes of divergence, which were hypothesized as human information processing failures affecting the human state assumption, and to evaluate the effects of those failures on downstream processes and the human state assumption. Eleven accident case studies involving automation mode confusion were conducted to evaluate divergence using the process model of divergence. Eight of the case studies involved auto-throttle mode confusion and the three remaining cases involved divergence in other automation systems that resulted in controlled flight into terrain. The industry implications of the findings of the case studies were then discussed.

2016-04-28T00:00:00Z Yan, Chiwei Vaze, Vikrant Vanderboll, Allison Barnhart, Cynthia https://hdl.handle.net/1721.1/100800 2019-04-10T14:54:34Z 2016-01-12T00:00:00Z

Tarmac Delay Policies: A Passenger-Centric Analysis Yan, Chiwei; Vaze, Vikrant; Vanderboll, Allison; Barnhart, Cynthia In this paper, we analyze the effectiveness of the 2010 Tarmac Delay Rule from a passenger - centric point of view. The Tarmac Delay Rule stipulates that aircraft lift-off, or an opportunity for passengers to deplane, must occur no later than three hours after the cabin door closure at the gate of the departure airport; and that an opportunity for passengers to deplane must occur no later than three hours after the touchdown at the arrival airport. The Tarmac Delay Rule aims to protect enplaned passengers on commercial aircraft from excessively long delays on the tarmac upon taxi-out or taxi-in, and monetarily penalizes airlines that violate the stipulated three-hour tarmac time limit. Comparing the actual flight schedule and delay data after the Tarmac Delay Rule was in effect with that before, we find that the Rule has been highly effective in reducing the frequency of occurrence of long tarmac times. However, another significant effect of the rule has been the rise in flight cancellation rates. Cancellations result in passengers requiring rebooking, and often lead to extensive delay in reaching their final destinations. Using an algorithm to estimate passenger delay, we quantify delays to passengers in 2007, before the Tarmac Delay Rule was enacted, and compare these delays to those estimated for hypothetical scenarios with the Tarmac Delay Rule in effect for that same year. Our delay estimates are calculated using U.S. Department of Transportation data from 2007. Through our results and several sensitivity analyses, we show that the overall impact of the current Tarmac Delay Rule is a significant increase in passenger delays, especially for passengers scheduled to travel on the flights which are at risk of long tarmac delays. We evaluate the impacts on passengers of a number of rule variations, including changes to the maximum time on the tarmac, and variations in that maximum by time-of-day. Through extensive scenario analyses, we conclude that a better balance between the conflicting objectives of reducing the frequency of long tarmac times and reducing total passenger delays can be achieved through a modified version of the existing rule. This modified version involves increasing the tarmac time limit to 3.5 hours and only applying the rule to flights with planned departure times before 5pm. Finally, in order to implement the Rule more effectively, we suggest the tarmac time limit to be defined in terms of the time when the aircraft begin returning to the gate instead of being defined in terms of the time when passengers are allowed to deplane.

2016-01-12T00:00:00Z Midkiff, Alan H. Hansman, R. John https://hdl.handle.net/1721.1/96074 2019-04-10T09:42:58Z 2015-03-18T00:00:00Z

Identification of Important "Party Line" Informational Elements and the Implications for Situational Awareness in the Datalink Environment Midkiff, Alan H.; Hansman, R. John Air/ground digital datalink communications are an integral component of the FAA's Air Traffic Control (ATC) modernization strategy. With the introduction of datalink into the ATC system, there is concern over the potential loss of situational awareness by flight crews due to the reduction in the "party line" information available to the pilot. "Party line" information is gleaned by flight crews overhearing communications between ATC and other aircraft. In the datalink environment, party line information may not be available due to the use of discrete addressing. Information concerning the importance, availability, and accuracy of party line elements was explored through an opinion survey of active air carrier flight crews. The survey identified numerous important party line elements. These elements were scripted into a full-mission flight simulation. The flight simulation experiment examined the utilization of party line information by studying subject responses to the specific information elements. Some party line elements perceived as important were effectively utilized by flight crews in the simulated operational environment. However, other party line elements stimulated little or no increase in situational awareness. The ability to assimilate and use party line information appeared to be dependent on workload, time availability, and the tactical/strategic nature of the situations. In addition, the results of both the survey and the simulation indicated that the importance of party line information appeared to be greatest for operations near or on the airport. This indicates that caution must be exercised when implementing datalink communications in these high workload, tactical sectors.

2015-03-18T00:00:00Z Odoni, Amedeo R. Bowman, Jeremy Delahaye, Daniel Deyst, John J. Feron, Eric Hansman, R. John Khan, Kashif Kuchar, James K. Pujet, Nicolas Simpson, Robert W. https://hdl.handle.net/1721.1/96073 2019-04-12T13:54:40Z 2015-03-18T00:00:00Z

Existing and Required Modeling Capabilities for Evaluating ATM Systems and Concepts Odoni, Amedeo R.; Bowman, Jeremy; Delahaye, Daniel; Deyst, John J.; Feron, Eric; Hansman, R. John; Khan, Kashif; Kuchar, James K.; Pujet, Nicolas; Simpson, Robert W. ATM systems throughout the world are entering a period of major transition and change. The combination of important technological developments and of the globalization of the air transportation industry has necessitated a reexamination of some of the fundamental premises of existing ATM concepts. New ATM concepts have to be examined, concepts that may place more emphasis on: strategic traffic management; planning and control; partial decentralization of decision-making; and added reliance on the aircraft to carry to strategic ATM plans, with ground controllers confined primarily to a monitoring and supervisory role. 'Free Flight' is a case in point.

2015-03-18T00:00:00Z Hahn, Edward C. Hansman, R. John https://hdl.handle.net/1721.1/96072 2019-04-10T17:37:56Z 2015-03-18T00:00:00Z

An Experimental Study of the Effects of Automation on Pilot Situational Awareness in the Datalink ATC Environmental Hahn, Edward C.; Hansman, R. John An experiment to study how automation, when used in conjunction with datalink for the delivery of ATC clearance amendments, affects the situational awareness of aircrews was conducted. The study was focused on the relationship of situational awareness to automated Flight Management System (FMS) programing and the readback of ATC clearances. situational awareness was tested by issuing nominally unacceptable ATC clearances. Situational awareness was tested by issuing nominally unacceptable ATC clearances and measuring whether the error was detected by the subject pilots.The experiment also varied the mode of clearance delivery: Verbal, Textual, and Graphical. The error detection performance and pilot preference results indicate that the automated programming of the FMS may be superior to manual programming. It is believed that automated FMS programming may relieve some of the cognitive load, allowing pilots to concentrate on the strategic implications of a clearance amendment. Also, readback appears to have value, but the small sample size precludes a definite conclusion. Furthermore because textual and graphical modes of delivery offer different but complementary advantages for cognitive processing, a combination of these modes of delivery may be advantageous in a datalink presentation.

2015-03-18T00:00:00Z Allroggen, Florian Wittman, Michael Malina, Robert https://hdl.handle.net/1721.1/95968 2019-04-11T03:05:47Z 2015-03-11T00:00:00Z

How Air Transport Connects The World: A New Metric of Air Connectivity and Its Evolution Between 1990 And 2012 Allroggen, Florian; Wittman, Michael; Malina, Robert Scheduled air transport services connect airports throughout the world and thereby enable interaction on a global scale. By doing so, they spur globalization (Hummels, 2007) as well as social and economic development (Lakshmanan, 2011). In order to facilitate integration of regions into global value chains, planners, scholars and policymakers therefore need to understand as to how scheduled air transport services link a region to other markets. For this purpose, connectivity metrics have been developed, which measure the degree of connections between airports (Burghouwt, Redondi, 2013). In particular, the ‘connection quality-weighting’ approach (Veldhuis, 1997; Burghouwt, de Wit, 2005) has been used to compute the aggregate quality of all available connections at an airport with regard to their properties in quickly bridging distances. However, such a metric has neither been calibrated on the basis of observed passenger behavior nor been computed for the world’s airports across a multi-decade time series. This paper sets out to develop the first such metric and to discuss global airline network development between 1990 and 2012 from a connectivity perspective.

2015-03-11T00:00:00Z Gao, Hang https://hdl.handle.net/1721.1/91586 2019-04-10T23:57:08Z 2014-11-14T00:00:00Z

Aircraft Cruise Phase Altitude Optimization Considering Contrail Avoidance Gao, Hang Contrails have been suggested as one of the main contributors to aviation-induced climate impact in recent years. To reduce the climate impact of contrails, mitigation policies such as taxation will be necessary in the future to incentivize jet aircraft operators to reduce contrail production. Contrails form in regions of the atmosphere with the right ambient conditions and they can be avoided by flying around these regions; this research investigates one such contrail avoidance strategy that uses flight level optimization to minimize contrail formation. A cruise phase flight profile system model was developed in this research that optimizes for environmental objectives such as contrails, CO2, and NOx, alongside traditional objectives such as fuelburn and flight time. Using this system model and 11 different aircraft types on 12 weather days, a preliminary study was done to determine the price range of contrail taxation that would incentivize airlines to operationally avoid contrails. Result suggests a price range of 0.12$/NM to 1.13$/NM on contrail tax would effectively incentivize contrail avoidance. Furthermore, since operating costs differ depending on the type of aircraft, a single price on contrail tax may incentivize contrail avoidance on a small aircraft, but not larger ones. To account for this difference, a method of assigning contrail tax to different aircraft types is introduced using the aircraft maximum takeoff weight. Assuming airlines are incentivized to fly contrail avoidance strategies, the climate impact of the flight profiles was evaluated for 287 flights along 12 O-D pairs for the 24 hour day of April 12, 2010. Under various assumptions of contrail radiative forcing and time horizon of climate impact evaluation, the flight level optimization reduced the average climate impact per flight by as much as 39.1% from a baseline of wind-optimal flight at optimal cruise altitude. In comparison, a complementary lateral optimization method reduced 13.3% from the same baseline. Furthermore, flight level optimization shows to be more fuel efficient by reducing the climate impact of contrails by as much as 94% from the baseline, compared to 60% using the lateral approach. In terms of the CO2 emission from the additional fuelburn, the climate impact of lateral method was 4 times higher than the flight level approach. Lastly, result shows that designing for long-term environmental objectives is more energy efficient (reduction in climate impact per additional kilogram of fuel used) than short-term, which suggest reducing CO2 emission is favored over contrail avoidance in designing for climate impact optimal flight profiles.

2014-11-14T00:00:00Z Silva, Sathya Jensen, Luke https://hdl.handle.net/1721.1/90811 2019-04-12T12:47:26Z 2014-10-08T00:00:00Z

Pilot Perception and Use of ADS-B Traffic and Weather Services (TIS-B & FIS-B) Silva, Sathya; Jensen, Luke Automatic Dependent Surveillance – Broadcast (ADS-B) is a central component of the NextGen air traffic control modernization program. It is intended to improve traffic surveillance capabilities by sharing accurate aircraft position information between pilots and air traffic controllers. In addition, “ADS-B In” capability provides pilots with traffic information for nearby flights along with relevant weather and airspace information. Pilots can access these products using a variety of installed and portable avionics systems. This study was intended to evaluate potential benefits of ADS-B In traffic and weather services. Goals included identifying the factors that influence the decision whether to equip with ADS-B In as well as evaluating current pilot usage of traffic and flight information uplink services.

2014-10-08T00:00:00Z Jensen, Luke Hansman, R. John https://hdl.handle.net/1721.1/88517 2019-04-11T06:47:46Z 2014-07-29T00:00:00Z

Fuel Efficiency Benefits and Implementation Consideration for Cruise Altitude and Speed Optimization in the National Airspace System Jensen, Luke; Hansman, R. John This study examines the potential fuel burn benefits of altitude and speed optimization in the cruise phase of flight for domestic airlines in the United States. Airlines can achieve cost reductions and reduce environmental impact by making small modifications to the cruise phase operating condition. The efficiency of the National Airspace System can be improved with coordination between air traffic controllers, pilots, and airline dispatchers. This study builds off of prior work in this area to establish best-case benefits assuming full implementation of fuel-optimal cruise altitudes and speeds. In order to achieve these objectives, a cruise-phase fuel burn estimator was developed using publicly-available radar tracks and weather data. This estimator was used to examine 217,000 flights from 2012. Maximum benefits from altitude optimization (holding speed constant) were found to be on the order 1.96%. The majority of potential altitude benefits can be achieved using step climb optimization, with only marginal gain from cruise climb implementation. The maximum benefits for speed optimization (holding altitude constant) were found to be 1.94% with an average flight time increase of 3.5 minutes per flight. Simultaneous altitude and speed optimization yielded a potential cruise fuel burn reduction of 3.71%. In practice, operational considerations and barriers to implementation limit likely system fuel reduction to lower levels. High-benefit operations within the NAS are identified and potential implementation considerations are discussed.

2014-07-29T00:00:00Z Wittman, M.D. https://hdl.handle.net/1721.1/87064 2019-04-10T08:55:59Z 2014-05-20T00:00:00Z

2013 Data Update: Trends and Market Forces Shaping Small Community Air Service in the United States Wittman, M.D. This document is an update to MIT Small Community Air Service White Paper No. 1—Trends and Market Forces Shaping Small Community Air Service in the United States1. This report provides updated analysis and data appendices including 2013 schedule data. This will allow readers to investigate the continuing effects of U.S. airline capacity discipline and the changes in available domestic service at the 462 U.S. airports examined in the earlier report. As with the 2013 report, the data contained in this report has been sourced from Diio Mi.

2014-05-20T00:00:00Z Wittman, M.D. https://hdl.handle.net/1721.1/87063 2019-04-10T08:55:42Z 2014-05-20T00:00:00Z

An Assessment of Air Service Accessibility in U.S. Metropolitan Regions, 2007-2012 Wittman, M.D. Regional accessibility to air transportation is often of interest to airport executives, politicians, and the general public due to the positive economic impacts of frequent commercial airline service. However, measuring access to air service can be challenging, particularly for regions with multiple airports. While many models exist to measure airline network connectivity at individual airports, there is limited literature on the geographic aggregation of these metrics to assess regional accessibility. In this paper, we propose a new methodology to construct U.S. regional airport catchment areas using U.S. Census Bureau Primary Statistical Areas (PSAs). Using a connectivity index that evaluates airports on the quantity and quality of available service, air service accessibility scores are computed on a regional level for 323 PSAs from 2007-2012. We find that most U.S. regions lost access to air service during the study period in the midst of domestic schedule rationalization and airline “capacity discipline.” Accessibility scores for each PSA from 2007 to 2012 are available in an appendix. On average, metropolitan regions in the United States lost about 11.6% of their accessibility to commercial air transportation between 2007 and 2012. Mid-sized regions of 500,000 - 5 million people lost the most access to air service—about 14.4% on average—aligning with past work that suggests that medium-sized communities have been harmed most by airline capacity discipline. In multi-airport regions, losses in service at primary airports outweighed some consolidation in service at larger hubs, leading to net losses in accessibility in most cases. The results of the accessibility model can be used by regional planners, policy-makers, and airport officials to understand how various regions in the U.S. lost or gained access to air transportation as a result of the Great Recession and airline capacity strategies. Additionally, the proposed catchment area definition provides a useful framework for further discussion of the demographic and geographic determinants of successful commercial air service.

2014-05-20T00:00:00Z Wittman, Michael D. https://hdl.handle.net/1721.1/83610 2019-04-11T11:32:18Z 2014-01-08T00:00:00Z

Public Funding of Airport Incentives: The Efficacy of the Small Community Air Service Development Grant (SCASDG) Program Wittman, Michael D. As U.S. airlines began to restrict available domestic capacity at smaller airports in 2008 as a result of higher fuel prices and an economic downturn, these airports have increasingly started to rely on incentive packages comprised of revenue guarantees, waived or reduced airport use fees, marketing support, or direct subsidies to attract new service. There are two main federal programs that provide funding for such incentives for small U.S. airports: the Essential Air Service (EAS) program and the Small Community Air Service Development Grant (SCASDG) program. While the EAS program has received considerable academic attention, there has been no comprehensive analysis of the success of SCASDG recipients in attracting and retaining their targeted air service. Using a metric of SCASD grant success, this paper evaluates the outcomes of 115 SCASD grantees from 2006-2011. In each year, fewer than half of the grant recipients were ultimately successful in meeting the goals of their proposal. Three case studies suggest that successful grantees often had signi cant community or airline support prior to submitting their grant and were located in slightly larger-than-average communities. Further careful consideration is necessary to determine whether reform of the SCASDG program is warranted to more e ectively support the development of small community air service in the United States.

2014-01-08T00:00:00Z Kunzi, Fabrice Hansman, R. John https://hdl.handle.net/1721.1/82031 2019-04-11T00:02:31Z 2013-11-07T00:00:00Z

Development of a High-Preceision ADS-B Based Conflict Alerting System for Operations in the Airport Enviornment Kunzi, Fabrice; Hansman, R. John The introduction of Automatic Dependent Surveillance - Broadcast (ADS-B) as the future source of aircraft surveillance worldwide provides an opportunity to introduce high-precision airborne conflict alerting systems for operations in high-density traffic environments. Current alerting systems have been very successful at preventing mid-air collisions in the en-route environment but have limited benefit in high-density environments such as near airports where most mid-air collisions occur (59%). Furthermore, introducing an ADS-B-enabled conflict alerting system generates an incentive for General Aviation users to voluntarily equip with ADS-B avionics.

2013-11-07T00:00:00Z Kolos-Lakatos, Tamas Hansman, R. John https://hdl.handle.net/1721.1/80777 2019-04-12T20:48:00Z 2013-09-17T00:00:00Z

The Influence Of Runway Occupancy Time And Wake Vortex Separation Requirements On Runway Throughput Kolos-Lakatos, Tamas; Hansman, R. John Air traffic growth in the U.S. has led to runway capacity constraints in the air transportation network. There has been limited new construction of runways due to land availability. One approach to increase capacity of existing runways is to reduce inter-arrival separations during the final approach phase of flight. This study evaluates two major elements influencing runway capacity; runway occupancy and wake vortex separation, and under what conditions each becomes a constraint to runway capacity. A detailed analysis of runway occupancy time measurements and wake vortex separation measurements is performed for Boston, Philadelphia, New York La Guardia, and Newark airports based on Airport Surface Detection Equipment Model-X (ASDE-X) aircraft surveillance data. The findings of this study indicate that runway occupancy does not necessary scale with aircraft size. Small aircraft often occupy the runway as long as large aircraft, which limits the potential for reduced separations behind small aircraft. The results also indicate that high-speed runway exits can make a significant difference in runway occupancy. Runways equipped with high-speed exits have lower runway occupancy times than runways equipped with standard 90-degree exits. Comparison of runway occupancy times in Visual Meteorological Conditions (VMC) and Instrument Meteorological Conditions (IMC) suggest no significant difference between the two weather conditions. Wake vortex separation measurements show that aircraft pairs with small lead aircraft receive longer separation buffers than other aircraft pairs, and airports with more runways implement longer separation buffers. The comparison of landing time intervals and runway occupancy illustrates that wake vortex separation requirements limit runway capacity when heavy or Boeing 757 is the lead aircraft. Lastly, this study evaluates the runway capacity benefits of reduced wake separation requirements for the aircraft re-categorization (RECAT) program. The results estimate an 8.2-8.3% increase in runway capacity at Philadelphia and at Newark, a 7.8% increase at Boston, and a 5.1% increase at La Guardia. The magnitude of benefits strongly depends on how the local traffic mix looks like.

2013-09-17T00:00:00Z Wittman, Michael D. Swelbar, William S. https://hdl.handle.net/1721.1/79878 2019-04-11T06:21:40Z 2013-08-15T00:00:00Z

Evolving Trends of U.S. Domestic Airfares: The Impacts of Competition, Consolidation, and Low-Cost Carriers Wittman, Michael D.; Swelbar, William S. This paper investigates the effects of flight reductions and disciplined airline capacity management strategies on average one-way domestic airfares at 445 U.S. airports from 2007-2012. Average one-way airfares are found to have increased at most airports during the study period, adjusting for inflation. Secondary and tertiary airports in multi-airport regions often saw larger increases in average fares than primary airports in those regions. The effects of low-cost carriers (LCCs) such as Southwest Airlines and JetBlue Airways on average one-way fares are also investigated. While the presence of low-cost carriers is still associated with a downward pressure on fares, the famous "Southwest effect" has diminished over time. Instead, JetBlue Airways is now the airline that is associated with the largest decline in average fares at U.S. airports.

2013-08-15T00:00:00Z Silva, Sathya Cho, HongSeok Kunzi, Fabrice Hansman, R. John https://hdl.handle.net/1721.1/79796 2019-04-11T11:19:57Z 2013-08-06T00:00:00Z

Human Factors Flight Testing of an ADS-B Based Traffic Alerting System for General Aviation Silva, Sathya; Cho, HongSeok; Kunzi, Fabrice; Hansman, R. John Mid-air collisions are a concern for general aviation. Current traffic alerting systems have limited usability in the airport environment where a majority of mid-air collisions occur. A Traffic Situation Awareness with Alerting Application (TSAA) has been developed which uses Automatic Dependent Surveillance – Broadcast (ADS-B), a Global Positioning System (GPS) based surveillance system, to provide reliable alerts in a condensed environment. TSAA was designed to be compatible with general aviation operations. It was specifically designed to enhance traffic situation awareness and provide traffic alerting. The system does not include guidance or resolution advisories. In addition, the design was consistent with established standards, previous traffic alerting system precedents, as well as air traffic control precedent. Taking into account the potential financial burden associated with installation of a multi-function display (MFD), an audio based TSAA system was also designed to account for constrained cockpit space and the added cost of a MFD.

2013-08-06T00:00:00Z Li, Lishuai Hansman, R. John https://hdl.handle.net/1721.1/79344 2019-04-11T07:07:09Z 2013-06-17T00:00:00Z

Anomaly Detection in Airline Routine Operations Using Flight Data Recorder Data Li, Lishuai; Hansman, R. John In order to improve safety in current air carrier operations, there is a growing emphasis on proactive safety management systems. These systems identify and mitigate risks before accidents occur. This thesis develops a new anomaly detection approach using routine operational data to support proactive safety management. The research applies cluster analysis to detect abnormal flights based on Flight Data Recorder (FDR) data. Results from cluster analysis are provided to domain experts to verify operational significance of such anomalies and associated safety hazards. Compared with existing methods, the cluster-based approach is capable of identifying new types of anomalies that were previously unaccounted for. It can help airlines detect early signs of performance deviation, identify safety degradation, deploy predictive maintenance, and train staff accordingly. The first part of the detection approach employs data-mining algorithms to identify flights of interest from FDR data. These data are transformed into a high-dimensional space for cluster analysis, where normal patterns are identified in clusters while anomalies are detected as outliers. Two cluster-based anomaly detection algorithms were developed to explore different transformation techniques: ClusterAD-Flight and ClusterAD-Data Sample. The second part of the detection approach is domain expert review. The review process is to determine whether detected anomalies are operationally significant and whether they represent safety risks. Several data visualization tools were developed to support the review process which can be otherwise labor-intensive: the Flight Parameter Plots can present raw FDR data in informative graphics; The Flight Abnormality Visualization can help domain experts quickly locate the source of such anomalies. A number of evaluation studies were conducted using airline FDR data. ClusterAD-Flight and ClusterAD-Data Sample were compared with Exceedance Detection, the current method in use by airlines, and MKAD, another anomaly detection algorithm developed at NASA, using a dataset of 25519 A320 flights. An evaluation of the entire detection approach was conducted with domain experts using a dataset of 10,528 A320 flights. Results showed that both cluster-based detection algorithms were able to identify operationally significant anomalies that beyond the capacities of current methods. Also, domain experts confirmed that the data visualization tools were effective in supporting the review process.

2013-06-17T00:00:00Z Wittman, Michael D. Swelbar, William S. https://hdl.handle.net/1721.1/79091 2019-04-11T10:58:48Z 2013-06-11T00:00:00Z

Modeling Changes in Connectivity at U.S. Airports: A Small Community Perspective Wittman, Michael D.; Swelbar, William S. There currently exists no industry-standard model for measuring an airport's level of connectivity to the global air transportation network. This discussion paper introduces the Airport Connectivity Quality Index (ACQI)--a new intuitive metric to compute airport connectivity. Unlike other connectivity models, the ACQI considers both the quantity and quality of available non-stop and connecting destinations, as well as the frequency of service. The metric can be used to examine connectivity trends at a single airport across time or across multiple airports by category, region, or size. The discussion paper contains a thorough review of past work in connectivity and accessibility modeling, and the ACQI model formulation is discussed in detail. Trends in connectivity at airports of all sizes from 2007-2012 are reviewed and discussed. Particular attention is paid to connectivity at smaller airports, which have been largely ignored in other research. Appendices containing connectivity scores for 462 U.S. airports from 2007-2012 conclude the report.

2013-06-11T00:00:00Z Stilwell, Justin Hansman, R. John https://hdl.handle.net/1721.1/78908 2019-04-11T10:45:40Z 2013-05-16T00:00:00Z

The Importance of Air Transportation to the U.S. Economy: Analysis of Industry Use and Proximity to Airports Stilwell, Justin; Hansman, R. John This thesis investigates broader impacts of air transportation on U.S. economic productivity, as well as market access and business location, in order to help identify how aviation supports the national economy. More traditional economic impacts are reviewed before turning to enabling impacts. Mechanisms by which air transportation might enhance economic productivity are proposed and a production model is constructed as a framework for exploring the validity of these mechanisms. Two analyses are conducted which should provide new insights to the FAA on the importance of air transportation to the U.S. economy. Focusing on the demand side of the economy, a detailed analysis of input-output (I-O) data from the Bureau of Economic Analysis (BEA) identifies where air transportation appears to be especially critical to economic production. On the supply side, U.S. Census Bureau data is used to map distributions of population, business establishments, and Fortune 500 headquarters from hub airports. Additional distribution analyses are performed for cargo airports and for select metropolitan areas. Analyses of intermediate use of air transportation provide weaker evidence than initially hypothesized as to aviation’s role in supporting productivity growth. Both sets of analyses confirm that the importance of air transportation to industry is not uniform and that the government and services sectors appear to benefit from and take advantage of access to aviation more than other industry sectors. In particular, the analyses of business location relative to airports provide evidence that many service and high-value economic sectors are more concentrated near hub airports than are other industry sectors for which air transportation adds less value.

2013-05-16T00:00:00Z Sandberg, Melanie Reynolds, Tom Khadikar, Harshad Balakrishnan, Hamsa https://hdl.handle.net/1721.1/77136 2019-04-12T20:45:34Z 2013-02-15T00:00:00Z

Airport Characterization for the Adaptation of Surface Congestion Management Approaches Sandberg, Melanie; Reynolds, Tom; Khadikar, Harshad; Balakrishnan, Hamsa Surface congestion management has received increased attention worldwide, largely due to its potential to mitigate operational inefficiencies and environmental impact. Most prior efforts have focused on demonstrations of a proposed congestion management approach at a particular airport, and not on the adaptation of a particular approach to a range of airport operating environments. This paper illustrates the challenges involved with adapting any class of surface congestion management approaches to different airports. Data and case studies from Boston Logan International Airport, New York’s LaGuardia Airport and Philadelphia International Airport are used to illustrate the diversity in operating environments. The paper then proposes techniques for characterizing airport surface operations using site surveys and operational data. Finally, it shows how these characterizations can be used for the adaptation of a given congestion management approach to different airports.

2013-02-15T00:00:00Z Shetty, Kamala https://hdl.handle.net/1721.1/72392 2019-04-11T07:47:31Z 2012-08-28T00:00:00Z

Current and Historical Trends in General Aviation in the United States Shetty, Kamala General aviation (GA) is an important component of aviation in the United States. In 2011, general aviation and air taxi operations represented 63% of all towered opera- tions in the United States, while commercial aviation was responsible for 34% of those operations. It is clear that GA is a considerable component of the national airspace and airport system, even when only accounting for towered operations. Because of this signi cant presence, insight into GA is relevant to issues in air tra c manage- ment, air transportation infrastructure, and aviation safety, among others. Beyond the operational aspect, GA is of signi cance to society as a whole and to other stake- holders, including pilots groups, aircraft manufacturers, and the work force. In 2009, general aviation generated 496,000 jobs and its total economic contribution to the U.S. economy was valued at $76.5 billion. However, a comparison of general aviation's impact on jobs and on the economy between 2008 and 2009, shows a 20% decrease in jobs and a 21% decrease in total economic impact in the course of a year. There is also a signi cant decreasing trend in the active pilot population, along with steady decreases in GA ight hours and towered operations. The objective of this thesis is to explore the details of these changing trends and to determine what drives and what hinders general aviation activity in the country. A combination of data analysis and the development of a survey administered to general aviation pilots shed light on what has driven activity in the past on a national scale, what factors a ect an individual pilot's level of activity, and what challenges the general aviation community faces in the future.

2012-08-28T00:00:00Z Tao, Tony S. Hansman, R. John https://hdl.handle.net/1721.1/71131 2019-04-10T13:24:41Z 2012-06-11T00:00:00Z

Design and Development of a High-Altitude, In-Flight-Deployable Micro-UAV Tao, Tony S.; Hansman, R. John A micro-UAV system was developed to provide maximum endurance for a small atmospheric sensing payload. The system, composed of a micro-UAV and protective case, folds and fits into a MJU-10/B flare cartridge (7.1” x 2.4” x1.9”) and is designed to be ejected in-flight from altitudes up to 30,000 ft. at 300 G, to open and unfold in freefall, and to autonomously fly, sense, and transmit data for up to 45 minutes at maximum altitude. The µ UAV has a wingspan of 11.8”, a length of 6.6”, and a mass of 220grams...

2012-06-11T00:00:00Z Bishop, Kristina Hansman, R. John https://hdl.handle.net/1721.1/71120 2019-04-10T13:24:40Z 2012-06-07T00:00:00Z

Assessment of the Ability of Existing Airport Gate Infrastructure to Accommodate Transport Category Aircraft with Increased Wingspan for Improved Fuel Efficiency Bishop, Kristina; Hansman, R. John The continuous trend of rising fuel prices increases interest in improving the fuel efficiency of aircraft operations. Additionally, since fuel burn is directly linked to aircraft CO2 emissions, reducing fuel consumption has environmental benefits. One approach to reducing airline cost and mitigating environmental impacts of aviation is to achieve higher fuel efficiency by increasing aircraft wingspan. One concern is that airports may not be able to accommodate increased-wingspan aircraft since existing gate infrastructure may have been sized for the past and current aircraft. This results in a potential tradeoff for airlines; increasing wingspan increases fuel efficiency, but it also limits the number of gates available to maintain current aircraft operations. The objective of this thesis is to evaluate this tradeoff...

2012-06-07T00:00:00Z Butchibabu, Abhizna Hansman, R. John https://hdl.handle.net/1721.1/70570 2019-04-12T15:35:58Z 2012-05-10T00:00:00Z

Evaluating The Depiction of Complex RNAV/RNP Procedures and Analyzing a Potential De-Cluttering Technique Butchibabu, Abhizna; Hansman, R. John Performance Based Navigation (PBN) is a key element of the Federal Aviation Administration’s (FAA) NextGen Program. In order to increase National Airspace System (NAS) capacity and efficiency, PBN routes and procedures are being developed, including Area Navigation (RNAV) and Required Navigation Performance (RNP) procedures. RNAV enables aircraft to fly directly from point-to-point on any desired flight path using ground- or spaced-based navigation aids. RNP is RNAV with the addition of onboard monitoring and alerting capability. Both RNAV and RNP procedures allow aircraft to fly accurate routes without relying on ground-based navigation aids. RNAV and RNP procedures facilitate more efficient design of airspace and procedures, offering significant safety improvements and flexibility to negotiate terrain, as well as improving airspace capacity and operational efficiency. The initial implementation of RNAV and RNAV (RNP) procedures has raised several human factors issues. RNAV (RNP) Instrument Approach Procedures (IAP) and RNAV Standard Instrument Departures (SID) and Standard Terminal Arrivals (STARs) often have more waypoints, altitude constraints and other elements than conventional procedures, resulting in charts being cartographically complex. Thus, a chart review was conducted to objectively understand the procedure elements that contributed to increased information density and high levels of visual clutter. A total of sixty-three approach, fifty-two departure, and fifty-four arrival procedures were analyzed. Primary findings were that the factors associated with high levels of visual clutter included having multiple flight paths per page for approach and departure procedures, and having complex altitude constraints for arrival procedures. Multiple waypoints per path was also a factor for both arrivals and approaches. In addition, having RF legs were additional factor contributing to visual clutter for approach procedures. One method to mitigate the increased information density and visual clutter on the RNAV and RNP procedure depiction is to reduce the number of flight paths shown on a single page by separating the depicted paths to multiple pages. However, there are a number of drawbacks to 4 this clutter mitigation technique. Example drawbacks include having more paper to carry in the flight deck and more time spent searching for the correct page within a set of separated pages. An experiment was conducted to determine the effect of reducing the number of paths depicted on single-page “Modified” charts. FAA AeroNav Products and Jeppesen created versions of the Modified chart in their standard cartographical conventions. The experiment was conducted to evaluate whether these Modified charts would impact information retrieval time and accuracy compared with the “Current” charts being used now. Current FAA AeroNav Products and Jeppesen charts were used as the baseline condition. Six procedures were studied, including three RNAV departure procedures from Dallas/Fort Worth, Las Vegas, and Salt Lake City airports, and three RNAV (RNP) approach procedures from Boise, Bozeman, and Palm Springs airports. During the experiment, pilots were shown the same procedure in Current and Modified chart formats.

2012-05-10T00:00:00Z Alverne Falcão de Albuquerque Filho, Emilio Hansman, R. John https://hdl.handle.net/1721.1/69913 2019-04-12T20:59:09Z 2012-04-03T00:00:00Z

Analysis of Airspace Traffic Structure and Air Traffic Control Techniques Alverne Falcão de Albuquerque Filho, Emilio; Hansman, R. John Air traffic controller cognitive processes are a limiting factor in providing safe and efficient flow of traffic. Therefore, there has been work in understanding the factors that drive controllers decision-making processes. Prior work has identified that the airspace structure, defined by the reference elements, procedural elements and pattern elements of the traffic, is important for abstraction and management of the traffic. This work explores in more detail this relationship between airspace structure and air traffic controller management techniques. This work looks at the current National Airspace System (NAS) and identifies different types of high altitude sectors, based on metrics that are likely to correlate with tasks that controllers have to perform. Variations of structural patterns, such as flows and critical points were also observed. These patterns were then related to groupings by origins and destinations of the traffic. Deeper pilot-controller voice communication analysis indicated that groupings by flight plan received consistent and repeatable sequences of commands, which were identified as techniques. These repeated modifications generated patterns in the traffic, which were naturally associated with the standard flight plan groupings and their techniques. The identified relationship between flight plan groupings and management techniques helps to validate the grouping structure-base abstraction introduced by Histon and Hansman (2008). This motivates the adoption of a grouping-focused analysis of traffic structures on the investigation of how new technologies, procedures and concepts of operations will impact the way controllers manage the traffic. Consideration of such mutual effects between structure and controllers' cognitive processes should provide a better foundation for training and for engineering decisions that include a human-centered perspective.

2012-04-03T00:00:00Z Hansman, R. John Mykityshyn, Mark https://hdl.handle.net/1721.1/69849 2019-04-12T15:30:44Z 1995-03-01T00:00:00Z

An Exploratory Survey of Informantion Requirements for Instrument Approach Charts Hansman, R. John; Mykityshyn, Mark

1995-03-01T00:00:00Z Hansman, R. John Mykityshyn, Mark https://hdl.handle.net/1721.1/69848 2019-04-12T20:57:38Z 2012-03-23T00:00:00Z

Current Issues in the Design and Information Content of Instrument Approach Charts Hansman, R. John; Mykityshyn, Mark The 1985 FAA Human Factors Research Plan identified chart design as one of the cockpit-related human performance problem areas which should be addressed through human factors research. Instrument Approach Charts, also referred to in this report as Instrument Approach Plates or IAP's, were chosen for initial human factors review over other chart types such as EN Route or Sectional Charts for two primary reasons. First, the IAP's depict the Terminal Arrival and Missed Approach Procedures which occur at low levels with minimal terrain clearance and consequently low tolerance for procedural errors. Secondly, the IAP's often have a high level of procedural and cartographic complexity, making careful human engineering critical.

2012-03-23T00:00:00Z Siegel, Diana Hansman, R. John https://hdl.handle.net/1721.1/66604 2019-04-12T14:58:03Z 2011-10-27T00:00:00Z

Development of an Autoland System for General Aviation Aircraft Siegel, Diana; Hansman, R. John Accidents due to engine failure, pilot disorientation or pilot incapacitation occur far more frequently in general aviation than in commercial aviation, yet general aviation aircraft are equipped with less safety-enhancing features than commercial aircraft. This thesis presents the design of an emergency autoland system that includes automatic landing site selection, guidance to the selected landing site and guidance along the final approach, in addition to the automatic landing capability provided by conventional autoland systems. The proposed system builds on the capability of a general aviation autopilot, flight management system and GPS/WAAS augmented, integrated navigation system. The system provides this automatic landing capability without the use of automatic throttle control and without the use of a radar altimeter, which are essential to conventional autoland systems, but are typically lacking on general aviation aircraft. The design addresses the challenge of no automatic throttle control by utilizing only two simple power settings: cruise power and zero power. The lack of radar altimeter is addressed by appropriate flare planning and placement of the target touchdown point. The approach from the point of autoland initiation, to the approach fix at the the landing site, is performed at cruise power, provided that power is available. The final approach from the approach fix to touchdown, is performed at zero power. Control of the touchdown point location during the final approach is achieved through adjustment of the length of the trajectory, whenever the aircraft’s glide performance deviates from the expected performance. The aircraft’s glide performance is measured online as the aircraft tracks the planned trajectory. The performance of the final design is evaluated in simulation in terms of touchdown point dispersion, sink rate and attitude on touchdown.

2011-10-27T00:00:00Z Balakrishnan, Hamsa Deonandan, Indira Simaiakis, Ioannis https://hdl.handle.net/1721.1/66491 2019-04-10T09:17:57Z 2011-10-19T00:00:00Z

Opportunities for Reducing Surface Emissions through Airport Surface Movement Optimization Balakrishnan, Hamsa; Deonandan, Indira; Simaiakis, Ioannis Aircraft taxiing on the surface contribute significantly to the fuel burn and emissions at airports. This report is an overview of PARTNER’s Project 21, which tries to identify promising opportunities for surface optimization to reduce surface emissions at airports, estimate the potential benefits of these strategies, and assess the critical implementation barriers that need to be overcome prior to the adoption of these approaches at airports. We also present a new queuing network model of the departure processes at airports that can be used to develop advanced queue management strategies to decrease fuel burn and emissions.

2011-10-19T00:00:00Z Idris, Husni R. Hansman, R. John https://hdl.handle.net/1721.1/66251 2019-04-10T09:17:53Z 2011-10-14T00:00:00Z

Observation and Analysis of Departure Planning Operations at Boston Logan International Airport Idris, Husni R.; Hansman, R. John The Departure Planner (DP) is a concept for a decision-aiding tool that is aimed at improving the departure operations performance at major congested airports. In order to support the development of the DP tool, the flow constraints and their causalities in the departure process – primarily responsible for generating inefficiencies and delays- need to be identified. This thesis is and effort to identify such flow constraints and gain a deep understanding of the underlying dynamics of the departure process based on field observations and data analysis at Boston Logan International Airport. It was observed that the departure process is a complex interactive queuing system, where aircraft queues from as a manifestation of the flow constraints. While departure delays were observed in all airport components (runways, taxiways, ramps and gates), it was concluded that the flow constraints manifest mainly at he runway system, which exhibits the largest delays and queues…

2011-10-14T00:00:00Z Ishutkina, Mariya A. Hansman, R. John https://hdl.handle.net/1721.1/66250 2019-04-10T10:37:32Z 2011-10-14T00:00:00Z

Analysis of the Interaction Between Air Transportation and Economic Activity: A Worldwide Perspective Ishutkina, Mariya A.; Hansman, R. John Air transportation usage and economic activity are interdependent. Air transportation provides employment and enables certain economic activities which are dependent on the availability of air transportation services. The economy, in turn, drives the demand for air transportation services resulting in the feedback relationship between the two. The objective of this work is to contribute to the understanding of the relationship between air transportation and economic activity. More specifically, this work seeks to (1) develop a feedback model to describe the relationship between air transportation and economic activity and (2) identify factors which stimulate or suppress air transportation development. To achieve these objectives this work uses an exploratory research method which combines literature review, aggregate data and case study analyses.

2011-10-14T00:00:00Z Morrison, James Yutko, Brian Hansman, R. John https://hdl.handle.net/1721.1/65891 2019-04-12T20:57:16Z 2011-09-20T00:00:00Z

Transitioning The U.S. Air Transportation System To Higher Fuel Costs Morrison, James; Yutko, Brian; Hansman, R. John The air transportation system enables economic growth and provides significant social benefits. Future increases and volatility in oil prices, as well as climate change policies, are likely to increase the effective cost of fuel. We investigate the expected impacts of higher fuel costs on the U.S. domestic air transportation system and discuss policy options to reduce negative economic and social effects. The 2004-08 fuel price surge is used as a historical case study. A stochastic simulation model is developed using price elasticity of demand assumptions and flight leg fuel burn estimates to understand the impacts of higher fuel costs. It was found that a 50% increase in fuel prices is expected to result in a 12% reduction in ASMs if all cost increases pass through to passengers. System revenues are expected to decrease marginally for fuel price increases up to 50%, but higher increases may result in significant revenue reductions. Small airports are expected to experience relatively larger decreases and greater volatility in traffic. Older aircraft, flying sectors significantly below their optimal fuel efficiency range, are expected to experience the greatest reductions in capacity. An airline case study demonstrates that a regional carrier may be less sensitive to increased fuel prices than other business models. Policy options to maintain small community access, to manage airport traffic volatility, and to improve fleet fuel efficiency are discussed. To transition the U.S. air transportation system to higher fuel costs, stakeholder action will be required.

2011-09-20T00:00:00Z Morrison, James Hansman, R. John Sgouridis, Sgouris https://hdl.handle.net/1721.1/65890 2019-04-12T20:57:16Z 2011-09-20T00:00:00Z

Game Theory Analysis of the Impact of Single Aisle Aircraft Competition on Fleet Emissions Morrison, James; Hansman, R. John; Sgouridis, Sgouris To meet aviation’s CO2 emission reduction targets while maintaining mobility in the face of increasing effective fuel costs, technology innovation will be required. The single aisle commercial aircraft market segment is the largest by quantity and value, but has the longest running product lines. New aircraft programs offer the largest potential gains in fuel efficiency, but are risky and require large capital investments. Re-engining existing airframes reduces risk and capital requirements, but offers lower potential fuel burn improvements. Incremental improvements to existing aircraft lines may entail the lowest risk. It is hypothesized that competition has important effects on manufacturers’ decisions to innovate and that these effects must be considered when designing policies to reduce CO2 emissions from aviation. An aircraft program valuation model is developed to estimate expected payoffs to manufacturers under different competitive scenarios. A game theory analysis demonstrates how the incentives for manufacturers to innovate may be altered by subsidies, technology forcing regulations, increased effective fuel costs, the threat of new entrants, and long-term competitive strategies. It is shown that increased competition may result in incumbent manufacturers producing re-engined aircraft while increased effective fuel costs may result in new aircraft programs. Incumbents’ optimal strategies may be to delay the entry into service of new single aisle aircraft until 2020-24, unless technology forcing regulations are implemented.

2011-09-20T00:00:00Z Yutko, Brian Hansman, R. John https://hdl.handle.net/1721.1/64685 2019-04-12T20:57:13Z 2011-06-27T00:00:00Z

Approaches to Representing Aircraft Fuel Efficiency Performance for the Purpose of a Commercial Aircraft Certification Standard Yutko, Brian; Hansman, R. John Increasing concern over the potential harmful effects of green house gas emissions from various sources has motivated the consideration of an aircraft certification standard as one way to reduce aircraft CO2 emissions and mitigate aviation impacts on the climate. In order to develop a commercial aircraft certification standard, a fuel efficiency performance metric and the condition at which it is evaluated must be determined. The fuel efficiency metric form of interest to this research is fuel/range, where fuel and range can either be evaluated over the course of a reference mission or at a single, instantaneous point. A mission-­‐based metric encompasses all phases of flight and is robust to changes in technology; however, definition of the reference mission requires many assumptions and is cumbersome for both manufacturers and regulators. An instantaneous metric based on fundamental aircraft parameters measures the fuel efficiency performance of the aircraft at a single point, greatly reducing the complexity of the standard and certification process; however, a single point might not be robust to future changes in aircraft technology. In this thesis, typical aircraft operations are assessed in order to develop evaluation assumptions for a mission-­‐based metric, Block Fuel divided by Range (BF/R), and an instantaneous metric, incremental fuel burn per incremental distance (inverse Specific Air Range (1/SAR)). Operating patterns and fuel burn maps are used to demonstrate the importance of mission range on fleet fuel burn, and thus the importance of a properly defined range evaluation condition for BF/R. An evaluation condition of 40% of the range at Maximum Structural Payload (MSP) limited by Maximum Takeoff Weight (MTOW) is determined to be representative for the mission-­‐based metric. A potential evaluation condition for 1/SAR is determined to be optimal speed and altitude for a representative mid-­‐cruise weight defined by half of the difference between MTOW and Maximum Zero Fuel Weight (MZFW). To demonstrate suitability as a potential surrogate for BF/R, correlation of 1/SAR with BF/R is shown for the current fleet, and a case study of potential future aircraft technologies is presented to show the correlation of improvements in the 1/SAR metric with improvements in BF/R.

2011-06-27T00:00:00Z Kunzi, Fabrice Hansman, R. John https://hdl.handle.net/1721.1/63174 2019-04-12T20:55:40Z 2011-06-02T00:00:00Z

ADS-B Benefits to General Aviation and Barriers to Implementation Kunzi, Fabrice; Hansman, R. John Automatic Dependent Surveillance -­‐ Broadcast (ADS-­‐B) will be the basis of the future surveillance system in the US. To achieve benefit from ADS-­‐B, aircraft have to be equipped with ADS-­‐B avionics across all stakeholders. General Aviation (GA) comprises over 96% of the active aircraft fleet in the US but average yearly utilization for GA aircraft is 21 times lower than that of commercial aircraft. Since many benefits from ADS-­‐B depend on aircraft utilization, concern exists that ADS-­‐B does not provide enough user benefit to GA, possibly resulting in delayed acceptance and aircraft equipage with ADS-­‐B avionics. One way of providing user benefits and thus increasing incentives for GA users to equip with ADS-­‐B is to create and implement ADS-­‐B applications that are of high value to those operators. ADS-­‐B Surveillance in non-­‐RADAR airspace and ADS-­‐B based Traffic Situation Awareness (TSA) are identified as two applications that are expected to provide significant benefit to GA. Both applications are evaluated and possible barriers to the delivery of benefit are identified. In order to identify where TSA would be most beneficial, ten years’ worth of NTSB mid-­‐air collision reports were reviewed. Ten years of ASRS and NMACS near mid-­‐air collision (MAC) reports were also reviewed. The analysis revealed that aircraft are most likely to encounter each other in the airport vicinity – specifically in the pattern (59% of MACs). Current Traffic Awareness systems are not reliable in that environment due to insufficient surveillance data quality. Surveillance data from ADS-­‐B , however, has much higher resolution. Therefore, ADS-­‐B based traffic alerting systems are expected to be capable of providing reliable alerting in such environments and would thus pose a significant incentive for GA to equip with ADS-­‐B. An analysis of the current availability of low altitude surveillance over the continental United States was conducted in order to identify where ADS-­‐B Low Altitude Surveillance would be beneficial. Providing low altitude surveillance has the potential to improve efficiency during IFR conditions. 27 towered airports with RADAR floors of more than 500ft have been identified. ADS-­‐B surveillance in those locations would create a significant benefit locally. Non-­‐towered airports without low altitude surveillance are more common (806 total). ADS-­‐B surveillance to such airports has the potential to increase airport acceptance rates in Instrument Flight weather and thus providing benefit to GA. However, in addition to providing surveillance, additional ATC procedures need to be developed to take advantage of such ADS-­‐B surveillance. The new procedures would allow ATC to remain in radio communication with aircraft operating at non-­‐towered airports, preventing the application of inefficient procedural control.

2011-06-02T00:00:00Z Kunzi, Fabrice Hansman, R. John https://hdl.handle.net/1721.1/63130 2019-04-10T11:53:44Z 2011-05-27T00:00:00Z

ADS-B Benefits to General Aviation and Barriers to Implementation Kunzi, Fabrice; Hansman, R. John Automatic Dependent Surveillance - Broadcast (ADS-B) will be the basis of the future surveillance system in the US. To achieve benefit from ADS-B, aircraft have to be equipped with ADS-B avionics across all stakeholders. General Aviation (GA) comprises over 96% of the active aircraft fleet in the US but average yearly utilization for GA aircraft is 21 times lower than that of commercial aircraft. Since many benefits from ADS-B depend on aircraft utilization, concern exists that ADS-B does not provide enough user benefit to GA, possibly resulting in delayed acceptance and aircraft equipage with ADS-B avionics. One way of providing user benefits and thus increasing incentives for GA users to equip with ADS-B is to create and implement ADS-B applications that are of high value to those operators. ADS-B Surveillance in non-RADAR airspace and ADS-B based Traffic Situation Awareness (TSA) are identified as two applications that are expected to provide significant benefit to GA. Both applications are evaluated and possible barriers to the delivery of benefit are identified. In order to identify where TSA would be most beneficial, ten years’ worth of NTSB mid-air collision reports were reviewed. Ten years of ASRS and NMACS near mid-air collision (MAC) reports were also reviewed. The analysis revealed that aircraft are most likely to encounter each other in the airport vicinity – specifically in the pattern (59% of MACs). Current Traffic Awareness systems are not reliable in that environment due to insufficient surveillance data quality. Surveillance data from ADS-B , however, has much higher resolution. Therefore, ADS-B based traffic alerting systems are expected to be capable of providing reliable alerting in such environments and would thus pose a significant incentive for GA to equip with ADS-B. An analysis of the current availability of low altitude surveillance over the continental United States was conducted in order to identify where ADS-B Low Altitude Surveillance would be beneficial. Providing low altitude surveillance has the potential to improve efficiency during IFR conditions. 27 towered airports with RADAR floors of more than 500ft have been identified. ADS-B surveillance in those locations would create a significant benefit locally. Non-towered airports without low altitude surveillance are more common (806 total). ADS-B surveillance to such airports has the potential to increase airport acceptance rates in Instrument Flight weather and thus providing benefit to GA. However, in addition to providing surveillance, additional ATC procedures need to be developed to take advantage of such ADS-B surveillance. The new procedures would allow ATC to remain in radio communication with aircraft operating at non-towered airports, preventing the application of inefficient procedural control.

2011-05-27T00:00:00Z Morrison, James Bonnefoy, Philippe Hansman, R. John Sgouridis, Sgouris https://hdl.handle.net/1721.1/62860 2019-04-09T16:46:51Z 2011-05-20T00:00:00Z

Investigation of the Impacts of Effective Fuel Cost Increase on the US Air Transportation Network and Fleet Morrison, James; Bonnefoy, Philippe; Hansman, R. John; Sgouridis, Sgouris The cost of aviation fuel increased 244% between July 2004 and July 2008, becoming the largest operating cost item for airlines. Given the potential for future increases in crude oil prices, as well as environmental costs (i.e. from cap and trade schemes or taxes), the effective cost of aviation fuel may continue to increase, further impacting airlines’ financial performance and the provision of air service nationwide. We evaluate how fuel price increase and volatility affected continental US air transportation networks and fleets in the short- and medium-term using the increase in the 2007-08 and 2004-08 periods as a natural experiment. It was found that non-hub airports serving small communities lost 12% of connections, compared to an average loss of 2.8%, July 2004-08. It is believed that reduced access to the national air transportation system had social and economic impacts for small communities. Complementary analyses of aircraft fuel efficiency, airline economics, and airfares provided a basis for understanding some airline decisions. Increased effective fuel costs will provide incentives for airlines to improve fleet fuel efficiency, reducing the environmental effects of aviation, but may cause an uneven distribution of social and economic impacts as airline networks adapt. Government action may be required to determine acceptable levels of access to service as the air transportation system transitions to higher fuel costs.

2011-05-20T00:00:00Z Morrison, James Sgouridis, Sgouris Hansman, R. John https://hdl.handle.net/1721.1/62856 2019-04-10T11:53:43Z 2011-05-20T00:00:00Z

Game Theory Analysis of Aircraft Manufacturer Innovation Strategies in the Face of Increasing Airline Fuel Costs Morrison, James; Sgouridis, Sgouris; Hansman, R. John The air transportation system is a vital infrastructure that enables economic growth and provides significant social benefits. Future increases and volatility in crude oil prices, as well as environmental charges, are likely to increase the effective cost of fuel. We investigate the impacts of effective fuel cost increase on the US air transportation system historically and perform a game theory analysis of the impact of manufacturer competition on the introduction of new, more fuel efficient aircraft. The cost of jet fuel increased 244% between July 2004 and July 2008, providing a natural experiment to evaluate how fuel price increase affected continental US networks and fleets. It was found that non-hub airports serving small communities lost 12% of connections, compared to a system-wide average loss of 2.8%. Increased effective fuel costs will provide incentives for airlines to improve fleet fuel efficiency, reducing the environmental impacts of aviation, but may cause an uneven distribution of social and economic impacts if small communities suffer greater loss of mobility. Government action may be required to determine acceptable levels of access as the system transitions to higher fuel costs. Technology innovation may act as a long-term hedge against increasing effective fuel costs, enabling mobility to be maintained. The single aisle commercial aircraft market segment is the largest, but has the longest running product lines. We hypothesize that competition has important effects on manufacturers’ decisions to innovate that must be considered when designing policies to reduce fleet emissions. An aircraft program valuation model is developed to estimate expected payoffs to manufacturers under competitive scenarios. A game theory analysis demonstrates how the incentives to innovate may be altered by subsidies, technology forcing regulations, increased effective fuel costs, the threat of new entrants, and long-term competitive strategies. Increased competition may result in incumbent manufacturers producing re-engined aircraft while increased effective fuel costs may result in new aircraft programs. Incumbents’ optimal strategies may be to delay the entry of new single aisle aircraft until 2020-24, unless technology forcing regulations are implemented.

2011-05-20T00:00:00Z Lovegren, Jonathan Hansman, R. John https://hdl.handle.net/1721.1/62196 2019-04-12T20:54:54Z 2011-04-13T00:00:00Z

Estimation of Potential Aircraft Fuel Burn Reduction in Cruise Via Speed and Altitude Optimization Strategies Lovegren, Jonathan; Hansman, R. John Environmental performance has become a dominant theme in all transportation sectors. As scientific evidence for global climate change mounts, social and political pressure to reduce fuel burn and CO2 emissions has increased accordingly, especially in the rapidly growing aviation industry. Operational improvements offer the ability to increase the performance of any aircraft immediately, by simply changing how the aircraft is flown. Cruise phase represents the largest portion of flight, and correspondingly the largest opportunity for fuel burn reduction. This research focuses on the potential efficiency benefits that can be achieved by improving the cruise speed and altitude profiles operated by flights today. Speed and altitude are closely linked with aircraft performance, so optimizing these profiles offers significant fuel burn savings. Unlike lateral route optimization, which simply attempts to minimize the distance flown, speed and altitude changes promise to increase the efficiency of aircraft throughout the entire flight. Flight data was collected for 257 flights during one day of domestic US operations. A process was developed to calculate the cruise fuel burn of each selected flight, based on aircraft performance data obtained from Piano-X and atmospheric data from NOAA. Improved speed and altitude profiles were then generated for each flight, representing various levels of optimization. Optimal cruise climbs and step climbs of 1,000 and 2,000 ft were analyzed, along with optimal and LRC speed profiles. Results showed that a maximum fuel burn reduction of 3.5% is possible in cruise given complete altitude and speed optimization; this represents 2.6% fuel reduction system-wide, corresponding to 300 billion gallons of jet fuel and 3.2 million tons of CO2 saved annually. Flights showed a larger potential to improve speed performance, with nearly 2.4% savings possible from speed optimization compared to 1.5% for altitude optimization. Few barriers exist to some of the strategies such as step climbs and lower speeds, making them attractive in the near term. As barriers are minimized, speed and altitude trajectory enhancements promise to improve the environmental performance of the aviation industry with relative ease.

2011-04-13T00:00:00Z Donaldson, Alexander D. Hansman, R. John https://hdl.handle.net/1721.1/60973 2019-04-09T18:06:06Z 2011-02-17T00:00:00Z

Improvement of Terminal Area Capacity in the New York Airspace Donaldson, Alexander D.; Hansman, R. John The New York airspace is the most congested in the U.S. air transportation network. Increasing capacity in this area is critical to ensure the balanced growth of traffic across the U.S. This study compares the total measured runway capacity at the New York airports with the achieved throughput of the New York airspace. The comparison is performed for six airspace configurations representing operations under different wind conditions, visibility and relative arrival and departure demand. The comparison shows that in all cases the capacity of the system of airports is lower than the total capacity of the airports considered individually by approximately 20%. This finding suggests that air traffic throughput in the New York area is constrained by shared airspace resources. If these constraints could be removed, these funding suggest that capacity could be increased approximately 20% without any airport infrastructure or procedure changes. An examination of procedures close to the airports is performed to identify fixed constraints. The impact of these constraints is not captured by the empirical analysis because these constraints are always present. This analysis identifies cases where new navigation technologies could be used to reduce the interactions between airports. The greatest potential for improvement is found to be in the lower performing configurations. Therefore procedural changes close to the airports may provide more benefit in reducing the variability of capacity between different configurations, rather than providing large increases in maximum capacity.

2011-02-17T00:00:00Z Simaiakis, Ioannis Balakrishnan, Hasmsa Khadilkar, Harshad Reynolds, Tom G. Hansman, R. John Reilly, B. Urlass, S. https://hdl.handle.net/1721.1/60882 2019-04-10T15:45:08Z 2011-02-02T00:00:00Z

Demonstration of Reduced Airport Congestion Through Pushback Rate Control Simaiakis, Ioannis; Balakrishnan, Hasmsa; Khadilkar, Harshad; Reynolds, Tom G.; Hansman, R. John; Reilly, B.; Urlass, S. Airport surface congestion results in significant increases in taxi times, fuel burn and emissions at major airports. This paper presents the field tests of a control strategy to airport congestion control at Boston Logan International Airport. The approach determines a suggested rate to meter pushbacks from the gate, in order to prevent the airport surface from entering congested states and reduce the time that flights spend with engines on while taxiing to the runway. The field trials demonstrated that significant benefits were achievable through such a strategy: during eight four-hour tests conducted during August and September 2010, fuel use was reduced by an estimated 12,000-15,000 kg (3,900-4,900 US gallons), while aircraft gate pushback times were increased by an average of only 4.3 minutes.

2011-02-02T00:00:00Z Simaiakis, Ioannis Balakrishnan, Hasmsa https://hdl.handle.net/1721.1/60881 2019-04-10T15:45:08Z 2011-02-02T00:00:00Z

Departure Throughput Study for Boston Logan International Airport Simaiakis, Ioannis; Balakrishnan, Hasmsa We propose a new parametric representation of the departure capacity of airports. In particular, we show how the departure capacity can be represented by the variation of the average departure throughput as a function of arrivals, conditioned on persistent departure demand. We also show how this approach can be extended to quantify the dependence of departure capacity on other parameters such as the fleet mix. The proposed approaches are illustrated through the parametric estimation of the departure capacity of Boston Logan International Airport (BOS).

2011-02-02T00:00:00Z Cafarelli, Deborah Hansman, R. John https://hdl.handle.net/1721.1/59842 2019-04-12T20:54:04Z 2010-11-05T00:00:00Z

Effect Of False Alarm Rate On Pilot Use And Trust Of Automation Under Conditions Of Simulated High Risk Cafarelli, Deborah; Hansman, R. John An experimental study was conducted to investigate the relationships between automation false alarm rate, human trust in automation, and human use of automation, specifically under conditions of simulated high risk. The experiment involved military pilots flying combat and non-combat missions while employing a missile warning sensor with two levels of automation. The experiment was performed in a high fidelity F-16 simulator with U.S. Air Force F-16 pilots as test subjects. Three sensor false alarm rates were tested. The results showed that the level of missile warning sensor automation preferred by the pilots was strongly dependent on the false alarm rate of the automation. The data demonstrated that as false alarm rate increased, pilot trust of the missile warning sensor decreased, resulting in the pilot preferring a lower level of automation. However, the results also showed that even when pilots expressed little trust in the system, they preferred to use some level of automation rather than turn the system off. This result was attributed to the cost/benefit tradeoff of using the automation, as well as the extreme difficulty and hazard associated with the task. Analysis of the pilot mean reaction time in response to a missile warning sensor alert showed that reaction time increased as the false alarm rate increased, although this effect appeared to be less significant the higher the false alarm rate. Missile hit data indicated that as false alarm rate increased, the number of missiles that hit the pilot’s aircraft also increased, demonstrating a degradation in pilot survivability. Missile hit results also indicated that using a higher level of automation improved pilot survivability for the scenarios tested.

2010-11-05T00:00:00Z Kar, Rahul Bonnefoy, Philippe Hansman, R. John https://hdl.handle.net/1721.1/56268 2019-04-10T07:50:19Z 2010-07-13T00:00:00Z

Dynamics of Implementation of Mitigating Measures to Reduce CO2 Emissions from Commercial Aviation Kar, Rahul; Bonnefoy, Philippe; Hansman, R. John Increasing demand for air transportation and growing environmental concerns motivate the need to implement measures to reduce CO2 emissions from aviation. Case studies of historical changes in the aviation industry have shown that the implementation of changes generally followed S-curves with relatively long time–constants. This research analyzed the diffusion characteristics of a portfolio of CO2 emission mitigating measures and their relative contribution to cumulative system wide improvements. A literature review identified 41 unique measures, including (1) technological improvements, (2) operational improvements, and (3) the use of alternative fuels. It was found that several operational changes can be implemented in the short term but are unlikely to significantly reduce CO2 emissions. Technology retrofits and some operational changes can be implemented in the medium term. 2nd and 3rd generation biofuels can significantly reduce carbon emissions but are likely to have long diffusion times and may not be available in sufficient quantities to the aviation industry. Technology measures in the form of next generation aircraft have the highest CO2 reduction potential, but only in the long term due to slow fleet turnover. An Aircraft Diffusion Dynamic Model (ADDM) was developed using System Dynamics modeling techniques to understand how the fleet efficiency will be influenced by the entry of various generations of aircraft with different levels of emissions performance. The model was used to evaluate effects of several future potential scenarios on the US narrow body jet fleet as well as their sensitivity to S-curve parameters. Results from the model showed that strategies that emphasize the early entry into service of available technology, as opposed to waiting and delaying entry for more fuel- efficient technology, have greater potential to improve fleet fuel-burn performance. Also, strategies that incentivize early retirement of older aircraft have marginal potential for reducing fuel burn. Future demand scenarios showed that the infusion of fuel-efficient aircraft alone is unlikely to reduce emissions below 2006 levels. Instead, a portfolio of measures that also include demand reduction mechanisms, operational improvements, and adoption of alternative fuels will be required in order to limit the growth of CO2 emissions from aviation.

2010-07-13T00:00:00Z Balakrishnan, Hamsa Lee, Hanbong https://hdl.handle.net/1721.1/51953 2019-04-10T12:17:14Z 2008-12-01T00:00:00Z

A Study of Tradeoffs in Scheduling Terminal-Area Operations Balakrishnan, Hamsa; Lee, Hanbong The terminal area surrounding an airport is an important component of the air transportation system, and efficient terminal-area schedules are essential for accommodating the projected increase in air traffic demand. Aircraft arrival schedules are subject to a variety of operational constraints, such as minimum separation for safety, required arrival time-windows, limited deviation from a first-come firstserved sequence, and precedence constraints. There is also a range of objectives associated with multiple stakeholders that could be optimized in these schedules; the associated tradeoffs are evaluated in this paper. A dynamic programming algorithm for determining the minimum cost arrival schedule, given aircraft-dependent delay costs, is presented. The proposed approach makes it possible to determine various tradeoffs in terminal-area operations. A comparison of maximum throughput and minimum average delay schedules shows that the benefit from maximizing throughput could be at the expense of an increase in average delay, and that minimizing delay is the more advantageous of the two objectives in most cases. A comprehensive analysis of the tradeoffs between throughput and fuel costs and throughput and operating costs is conducted, accounting for both the cost of delay (as reported by the airlines) and the cost of speeding up when possible (from models of aircraft performance).

2008-12-01T00:00:00Z Hansman, R. John Weibel, Roland E. https://hdl.handle.net/1721.1/47923 2019-04-12T20:50:38Z 2009-10-01T19:29:41Z

Assuring Safety through Operational Approval: Challenges in Assessing and Approving the Safety of Systems-Level Changes in Air Transportation Hansman, R. John; Weibel, Roland E. To improve capacity and efficiency of the air transportation system, a number of new systems-level changes have been proposed. Key aspects of the proposed changes are combined functionality across technology and procedures and large physical scale of deployment. The objective of this work is to examine the current safety assessment processes for systems-level changes and to develop an understanding of key challenges and implications for the assessment and approval of future systems-level changes. From an investigation of current U.S. and international safety regulatory policies and processes, a general model was created describing key processes supporting operational approval. Within this model, a framework defined as an influence matrix was developed to analyze key decisions regarding the required scope of analysis in safety assessment. The influence matrix represents the expected change in levels of risk due to changes in behavior of elements of a system. It is used to evaluate the appropriate scope of analysis in safety assessment. Three approaches to performing safety assessment of systems-level changes were analyzed using the framework: the risk matrix approach, target level of safety approach, and performance-based approach. Case studies were performed using eight implemented and pending systems-level changes. In this work, challenges expected in safety assessment of future systems-level changes were identified. Challenges include the large scope of proposed changes, which drives a need for a broad and deep scope of analysis, including the multiple hazards and conditions and complex interactions between components of a change and the external system. In addition, it can be expected that high safety expectations will increase the required accuracy of models and underlying data used in safety assessment. Fundamentally new operational concepts are also expected to expand the required scope of safety assessment, and a need to interface with legacy systems will limit achievable operations. The large scope of analysis expected for future changes will require new methods to manage scope of safety assessment, and insights into potential approaches are discussed.

2009-10-01T19:29:41Z Hansman, R. John Li, Lishuai https://hdl.handle.net/1721.1/46711 2019-04-10T16:55:03Z 2009-09-09T19:07:58Z

Experimental Studies of Cognitively Based Air Traffic Control Complexity Metrics for Future Operational Concepts Hansman, R. John; Li, Lishuai New procedures and technologies of Air Traffic Control (ATC) under development in Next Generation Air Transportation System (NextGen) will change controllers' tasks, roles, and responsibilities. However, cognitive complexity will remain one of the limiting factors in future system's capacity and none of existing complexity metrics can be directly extended to evaluate cognitive complexity under future operational concepts. Therefore, complexity metrics, applicable to future operational concepts, need to be developed. This thesis developed the structure for a cognitively based complexity metric, Modified Aircraft Count (MAC). Cognitive complexity is decomposed based on individual aircraft complexity factors and sector specific factors. The complexity contribution of each aircraft is summed and adjusted by sector level complexity factors. Cognitive principles, such as controller strategies, may be incorporated in aircraft specific complexity factors and sector level complexity factors. To investigate complexity factors in Modified Aircraft Count, two simulations were developed to explore two proposed NextGen operational concepts, including Time-Based Control at a Metering Fix and Dynamic Route Structure Control. Two experiments were designed to evaluate controller performance and subjective workload under the simulated operational concepts. The Time-Based Control at a Metering Fix was found to have enhanced schedule conformance, reduced operational errors and lower perceived complexity. The Dynamic Route Structure Control introduced longer hand-off acceptance times, however, no other significant changes of controller performance and subjective workload were found. A new complexity probe technique was developed and applied in the two experiments to explore individual aircraft complexity factors in Modified Aircraft Count. In the new complexity probe, participants were asked to identify high complexity aircraft from the screen shot of a traffic situation they had experienced. It was shown to be an effective tool to assess aircraft specific complexity factors. Four complexity factors (proximity to other aircraft, membership of a standard flow, proximity to weather, and projected proximity to other aircraft) were examined by the relationship between their corresponding observable factors and high complexity aircraft percentage. The chance of an aircraft being considered as of high complexity increased if the aircraft was closer to another aircraft, off the standard route structure, closer to the area impacted by weather, or more likely to be in a conflict in the future.

2009-09-09T19:07:58Z Hansman, R. John Ishutkina, Mariya https://hdl.handle.net/1721.1/44957 2019-04-10T11:14:08Z 2009-03-30T14:22:58Z

Analysis of the Interaction Between Air Transportation and Economic Activity: A Worldwide Perspective Hansman, R. John; Ishutkina, Mariya Air transportation usage and economic activity are interdependent. Air transportation provides employment and enables certain economic activities which are dependent on the availability of air transportation services. The economy, in turn, drives the demand for air transportation services resulting in the feedback relationship between the two. The objective of this work is to contribute to the understanding of the relationship between air transportation and economic activity. More specifically, this work seeks to (1) develop a feedback model to describe the relationship between air transportation and economic activity and (2) identify factors which stimulate or suppress air transportation development. To achieve these objectives this work uses an exploratory research method which combines literature review, aggregate data and case study analyses. First, this work uses data at the individual country level to identify different types of growth patterns between air transportation passengers and GDP for 139 countries. This analysis is then used to identify twenty-two representative countries which span a range of possible interaction behaviors, geographies and income categories. The case study analysis at the individual country level is performed to describe the air transportation impact for each individual economy. These findings help develop a feedback model which describes the relationship between air transportation and economic activity. Specifically, the analysis is used to describe (1) how air transportation flows of passengers and cargo enable the flows of goods, services, knowledge, tourism, investment, remittances and labor among economies and (2) how air transportation flows can affect the country’s factor, demand and business conditions. The feedback model is then extended to perform quantitative analysis of the evolution of the enabling impact of air transportation in a particular economy. Specifically, a quantitative system dynamics model is developed to describe the interaction between the demand for leisure travel and the resulting enabling impact of tourism on Jamaica’s economy. Case study analysis is also used to identify factors which may stimulate or suppress air transportation system development. The factors are identified both from the air transportation supply and demand sides. The following supply side change factors are identified: changes in the regulatory framework, infrastructure capability, vehicle capability and airline strategy. The air transportation demand is found to be directly affected by exogenous demand shocks, economic downturns, political and economic sanctions, and the development of other transportation modes. The analysis also identifies the following change factors which affect the demand indirectly by changing the country’s economic attributes: economic liberalization, institutional and political reforms, supporting infrastructure investment, exchange rate fluctuations, political and macroeconomic stability, growing consumer demand, and changes in management practices. This analysis of stimulating and suppressing factors helps to describe the role of government intervention in changing air transportation system development and its impact on economic activity. The results of this work can help guide further development efforts, investment and policy decisions pertaining to air transportation usage especially in developing economies.

2009-03-30T14:22:58Z Campos, Norma https://hdl.handle.net/1721.1/42838 2019-04-12T09:47:31Z 2008-09-01T00:00:00Z

Encouraging Technology Transition through Value Creation, Capture and Delivery Strategies: The Case of Data Link in the North Atlantic Airspace Campos, Norma This thesis studies the problem of data link in the NAT under a technology transition framework of value creation, capture, and delivery. Creating value through a new technology, such as data link, refers to designing competitive value propositions for stakeholders. Capturing value means recovering an investment in a technology through the value it creates. Delivering value refers to developing policies and business strategies to enable value capture. Realization of these concepts is necessary to guarantee technology transition.

2008-09-01T00:00:00Z Eguchi, Makato https://hdl.handle.net/1721.1/42008 2019-04-12T09:45:01Z 2008-05-01T00:00:00Z

System Dynamics Analysis of Incentives for Automatic Dependent Surveillance Broadcast (Ads-B) Equipage Eguchi, Makato The demand for air transportation is anticipated to continue to grow in the future. In order to accommodate future demands, the U.S. Joint Planning and Development Office (JPDO) proposed the Next Generation Air Transportation System (NextGen). One of the NextGen technologies currently under development is Automatic Dependent Surveillance – Broadcast (ADS-B), which is a new satellite-based surveillance technology.

2008-05-01T00:00:00Z Hansman, R. John Histon, Jonathan M. https://hdl.handle.net/1721.1/42006 2019-04-10T22:36:43Z 2008-08-01T00:00:00Z

Mitigating Complexity in Air Traffic Control: The Role of Structure-Based Abstractions Hansman, R. John; Histon, Jonathan M. Cognitive complexity is a limiting factor on the capacity and efficiency of the Air Traffic Control (ATC) system. A multi-faceted cognitive ethnography approach shows that structure, defined as the physical and informational elements that organize and arrange the ATC environment, plays an important role in helping controllers mitigate cognitive complexity. Key influences of structure in the operational environment and on controller cognitive processes are incorporated into a cognitive process model. Controllers are hypothesized to internalize the structural influences in the form of abstractions simplifying their working mental model of the situation. By simplifying their working mental model, these structure-based abstractions reduce cognitive complexity.

2008-08-01T00:00:00Z Hansman, R. John https://hdl.handle.net/1721.1/42000 2019-04-12T09:45:01Z 2003-09-01T00:00:00Z

Air Transportation: The Next 100 Years Challenges and Opportunities Hansman, R. John

2003-09-01T00:00:00Z Hu, Xiaojie https://hdl.handle.net/1721.1/41932 2019-04-09T15:55:14Z 2008-07-01T00:00:00Z

Technology Transition in the National Air Transportation System: Market Failure and Game Theoretic Analysis with Application to ADS-B Hu, Xiaojie Air traffic demand is increasing, but capacity is constrained by an antiquated air traffic control (ATC) infrastructure. The number of air traffic passengers in the U.S. is expected to grow from 738 million in 2005 to 1 billion in 2015. The number of commercial airline flights is expected to grow from 13 million in 2005 to 15 million in 2015. [22] Figure 1-1 shows the growth in air traffic demand in the United States in recent years.

2008-07-01T00:00:00Z Ishutkina, Masha Hansman, R. John https://hdl.handle.net/1721.1/41876 2019-04-12T09:43:30Z 2008-07-07T19:55:18Z

Analysis of Interaction between Air Transportation and Economic Activity Ishutkina, Masha; Hansman, R. John This paper uses both world-wide and country-level analysis to describe the relationship between air transportation and economic activity. In particular, we describe how economic, infrastructural, institutional and geographic factors affect the mapping of cargo and passenger flows to the enabled flows of labor, knowledge, investment, remittances, tourism and goods. We also identify the role of government and exogenous drivers in this relationship. We illustrate the relationship using several examples: Dubai in the United Arab Emirates, Jamaica, China and India.

2008-07-07T19:55:18Z Bonnefoy, Philippe Hansman, R. John https://hdl.handle.net/1721.1/41863 2019-04-09T16:32:22Z 2008-06-01T00:00:00Z

Scalability of the Air Transportation System and Development of Multi-Airport Systems: A Worldwide Perspective Bonnefoy, Philippe; Hansman, R. John With the growing demand for air transportation and the limited ability to increase capacity at some key points in the air transportation system, there are concerns that in the future the system will not scale to meet demand. This situation will result in the generation and the propagation of delays throughout the system, impacting passengers’ quality of travel and more broadly the economy. This thesis proposes the investigation of the mechanisms by which the air transportation system has scaled to meet demand in the past and is expected to do so in the future using a multi-level engineering systems approach. The air transportation system was first analyzed at the U.S. national level using network abstractions. In order to investigate limits in scaling of the U.S. air transportation network, theories of scale-free and scalable networks were used. It was found that the U.S. air transportation network was not scale-free due to capacity constraints at major airports, also preventing it from being scalable. However, the construction and analysis of a new network for which sets of two or more significant airports that serve passenger traffic in a metropolitan region (i.e. multi-airport systems) were aggregated into single nodes showed that it was scale-free and scalable. These results were also supported by a time series analysis of airport and multi-airport system growth. These analyses demonstrated the importance of regional level scaling mechanisms (i.e. development of multi-airport systems) in the ability of the air transportation system to adapt and scale to meet demand.

2008-06-01T00:00:00Z Mozdzanowska, Aleksandra Hansman, R. John https://hdl.handle.net/1721.1/41855 2019-04-12T09:43:27Z 2008-06-04T15:07:57Z

System Transition: Dynamics of Change in the US Air Transportation System Mozdzanowska, Aleksandra; Hansman, R. John The US Air Transportation System is currently facing a number of challenges including an increasing demand for travel and growing environmental requirements. In order to successfully meet future needs, the system will need to transition from its current state using a combination of technology, infrastructure, procedure, and policy changes. However, the complexities of the air transportation system make implementing changes a challenge. In particular, the multi-stakeholder nature of the system poses a significant barrier to transition. Historically, many changes in the air transportation system were driven by safety concerns and implemented following accidents which provided the momentum to overcome transition barriers. As a result of past changes, the system has become increasingly safe resulting in the emergence of new drivers for change. Security has emerged as a driver following the terrorist attacks of 9/11/2001 in the US and a number of system changes have since been implemented. Currently, capacity is one of the largest drivers of change. Addressing capacity issues requires solutions that can be accepted by stakeholders, and pass the necessary certification and approval requirements for implementation. The contribution of aviation to global greenhouse gas emissions is also becoming a significant driver for change in the system. The goal of this work is to understand how the air transportation system changes in response to safety, security, capacity, and environmental drivers for transition. In order to understand the dynamics of transition, historical cases of system change were studied. Twenty seven such cases have been analyzed to construct a feedback process model of transition and to explore specific change dynamics observed. These dynamics include: understanding the role of crisis events as catalyst for change; the effect that timing of solution development has on the overall time constant for change; the role that stakeholder objectives play in the transition process, and the use of approval and certification processes to stall or block change. Understanding the process of change in the US Air Transportation System can inform future changes in aviation as well as in other systems with similar properties.

2008-06-04T15:07:57Z Hansman, R. John https://hdl.handle.net/1721.1/40807 2019-04-11T06:53:42Z 2008-02-01T00:00:00Z

Overview of Recent Forces & Trends in the Airline Industry Hansman, R. John

2008-02-01T00:00:00Z Mozdzanowska, Aleksandra Weibel, Roland Marais, Karen Lester, Edward Weigel, Annalisa Hansman, R. John https://hdl.handle.net/1721.1/39093 2019-04-10T22:26:59Z 2007-09-20T00:00:00Z

Dynamics of Air Transportation System Transition and Implications for ADS-B Equipage Mozdzanowska, Aleksandra; Weibel, Roland; Marais, Karen; Lester, Edward; Weigel, Annalisa; Hansman, R. John The U.S. Air Transportation Systems faces substantial challenges in transforming to meet future demand. These challenges need to be understood and addressed in order to successfully meet future system needs. This paper uses a feedback model to describe the general system transition process and identify key issues in the dynamics of system transition, with particular emphasis on stakeholder cost-benefit dynamics and safety approval processes. Finally, in addition to identifying dynamics and barriers to change the paper proposes methods for enabling transition through the use of levers such as incentives, mandates, and infrastructure development. The implementation of ADS-B is studied as a pathfinding technology for planned Air Transportation System changes. The paper states that overcoming stakeholder barriers and ensuring efficient safety approval and certification process are the key enablers to the successful implementation of ADS-B.

2007-09-20T00:00:00Z Bonnefoy, Philippe Hansman, R. John https://hdl.handle.net/1721.1/39092 2019-04-12T09:30:39Z 2007-09-21T00:00:00Z

Scalability and Evolutionary Dynamics of Air Transportation Networks in the United States Bonnefoy, Philippe; Hansman, R. John With the growing demand for air transportation and the limited ability to increase capacity at key points in the air transportation system, there are concerns that, in the future, the system will not scale to meet demand. This situation will result in the generation and the propagation of delays throughout the system, impacting passengers’ quality of travel and more broadly the economy. There is therefore the need to investigate the mechanisms by which the air transportation system scaled to meet demand in the past and will do so in the future. In order to investigate limits to scale of current air transportation networks, theories of scale free and scalable networks were used. It was found that the U.S. air transportation network is not scalable at the airport level due to capacity constraints. However, the results of a case study analysis of multi-airport systems that led to the aggregation of these multiple airports into single nodes and the analysis of this network showed that the air transportation network was scalable at the regional level. In order to understand how the network evolves, an analysis of the scaling dynamics that influence the structure of the network was conducted. Initially the air transportation network scales according to airport level mechanisms –through the addition of capacity and the improvement of efficiency- but as infrastructure constraints are reached; higher level scaling mechanisms such as the emergence of secondary airports and the construction of new high capacity airports are triggered. These findings suggest that, given current and future limitations on the ability to add capacity at certain airports, regional level scaling mechanisms will be key to accommodating future needs for air transportation.

2007-09-21T00:00:00Z Pina, Patricia Hansman, R. John https://hdl.handle.net/1721.1/38870 2019-04-12T09:30:39Z 2007-09-01T00:00:00Z

Cognitive and Operational Implications of Non-Homogeneous Pina, Patricia; Hansman, R. John The air traffic management system is currently experiencing a significant transformation to provide better quality service and to match the increasing air traffic demand. This transformation requires airlines to retrofit their fleet. However, airlines implement new operating capabilities at different rates resulting in long transition periods in which aircraft with different equipage levels coexist in the same airspace. Mixed equipage environments can increase controller workload and task complexity, limit the operational benefits of new operating capabilities, and deteriorate the overall system performance. This study proposes a three dimensional approach to explore mixed equipage effects: (1) understand cognitive implications for controllers, (2) understand operational implications for users, and (3) understand system level implications. To further investigate mixed equipage effects and to illustrate the proposed approach, this study analyzed the implementation of reduced separation standards in the North Atlantic.

2007-09-01T00:00:00Z Jones, Eric Hansman, R. John https://hdl.handle.net/1721.1/38869 2019-04-11T08:11:25Z 2007-09-01T00:00:00Z

Approaches to Enhance Driver Situational Assessment Aids Jones, Eric; Hansman, R. John Collision warning systems encounter a fundamental trade-off between providing the driver more time in which to respond and alerting the driver unnecessarily. The probability that a driver successfully avoids a hazard increases as the driver is provided more time and distance in which to identify the hazard and execute the most effective response. However, alerting the driver at earlier, more conservative thresholds increases the probability that the alerts are unnecessary, either because sensor error has falsely identified a hazard or because the environment has changed such that a hazard is no longer a threat. Frequent unnecessary alerts degrade alert effectiveness by reducing trust in the system. The human-factors issues pertaining to a forward collision warning system (FCWS) were analyzed using an Integrated Human-Centered Systems approach, from which two design features were proposed: multi-stage alerting, which alerts the driver at a conservative early threshold, in addition to a more serious late threshold; and directional alerting, which provides the driver information regarding the location of the hazard that prompted the alert activation. Alerting the driver earlier increases the probability of a successful response by conditioning the driver to respond more effectively if and when evasive action is necessary. Directional alerting decreases the amount of time required to identify the hazard, while promoting trust in the system by informing the driver of the cause of the alert activation. The proposed design features were incorporated into three FCWS configurations, and an experiment was conducted in which drivers were equipped with the systems and placed in situations in which a collision would occur if they did not respond. Drivers who were equipped with multi-stage and directional alerting were more effective at avoiding hazardous situations than drivers who were not provided early alerting. Drivers with early alerting tended to respond earlier and more consistently, which promoted more successful responses. Subjective feedback indicates that drivers experienced high levels of acceptance, confidence, and trust in multi-stage and directional alerting.

2007-09-01T00:00:00Z Lester, Edward Hansman, R. John https://hdl.handle.net/1721.1/38468 2019-04-12T08:38:28Z 2007-08-01T00:00:00Z

Benefits and Incentives for ADS-B Equipage in the National Airspace System Lester, Edward; Hansman, R. John Automatic Dependent Surveillance – Broadcast (ADS-B) is a technology that can replace secondary surveillance radars and enhance cockpit situational awareness. It also has the potential to enable procedures not possible with current surveillance technology that would increase the capacity of the National Airspace System (NAS) in the US. Certain forms of ADS-B also have the bandwidth to upload weather and airspace information into the cockpit. However, prior to achieving the benefits of ADS-B, operators must equip with the technology. In order to voluntarily equip, owners and operators must receive benefits from the technology that outweigh the cost or receive other incentives. Through an online survey of stakeholders, applications of ADS-B with the strongest benefits to users are identified. In-cockpit data link offerings are explored in detail, along with a detailed analysis of ADS-B benefits for Hawaiian helicopter operators. The conclusions of this study are that ADS-B should be implemented in non-radar airspace along with busy terminal areas first to gain the most benefits from non-radar separation applications and traffic awareness applications. Also, the basis for the US dual ADS-B link decision is questioned, with a single 1090-ES based link augmented with satellite data link weather recommended.

2007-08-01T00:00:00Z Mozdzanowska, Aleksandra Weibel, Roland Lester, Edward Hansman, R. John https://hdl.handle.net/1721.1/37819 2019-04-12T08:38:28Z 2007-07-01T00:00:00Z

The Dynamics of Air Transportation System Transition Mozdzanowska, Aleksandra; Weibel, Roland; Lester, Edward; Hansman, R. John Both U.S. and European Air Transportation Systems face substantial challenges in transforming to meet future demand. This paper uses a feedback model to identify and describe key issues in the dynamics of system transition, with particular emphasis on stakeholder cost-benefit dynamics and processes for reviewing and implementing new system capabilities. Understanding of these dynamics is further reinforced through discussion of ADS-B and new runway construction examples. To implement the significant changes currently envisioned for ATM systems, it will be critical to structure system changes to anticipate and overcome stakeholder disagreements and improve the efficiency of the approval and implementation processes.

2007-07-01T00:00:00Z Mozdzanowska, Aleksandra Hansman, R. John https://hdl.handle.net/1721.1/37818 2019-04-12T07:37:30Z 2007-07-01T00:00:00Z

Crisis Events as a Catalyst for Change in the US Air Transportation Mozdzanowska, Aleksandra; Hansman, R. John Historically, aircraft accidents have preceded the implementation of many changes in the US Air Transportation System. These accidents act as catalytic events which generate awareness of a problem and pressure for change to occur. Specifically, aircraft accidents indicate the presence of safety problems. As past safety problems were addressed the frequency of accidents decreased causing new drivers for system change to emerge. Current drivers for change in the US Air Transportation System include increases in demand in the face of limited capacity, emerging requirements such as the need to address growing environmental concerns, and the need to replace and update aging system components. This paper explores the role of catalytic events in bringing change to the US Air Transportation System with a focus on the implications for capacity driven change. In order to address capacity constraints, infrastructure improvements, such as construction of new runways, or efficiency improvements, which would allow aircraft to be spaced closer together, can be made. However, changing the system in response to capacity can be difficult due to barriers posed by stakeholder conflicts and complex decision making and approval processes. The capacity problem, the need to address it, as well as the barriers to addressing it are presented in this paper. Finally, the paper explores the role of delays as catalytic capacity events and the likely actions following such an event.

2007-07-01T00:00:00Z Mozdzanowska, Aleksandra Weibel, Roland Lester, Edward Hansman, R. John https://hdl.handle.net/1721.1/37598 2019-04-09T18:58:34Z 2007-07-01T00:00:00Z

The Dynamics of Air Transportation System Transition Mozdzanowska, Aleksandra; Weibel, Roland; Lester, Edward; Hansman, R. John Both U.S. and European Air Transportation Systems face substantial challenges in transforming to meet future demand. This paper uses a feedback model to identify and describe key issues in the dynamics of system transition, with particular emphasis on stakeholder cost-benefit dynamics and processes for reviewing and implementing new system capabilities. Understanding of these dynamics is further reinforced through discussion of ADS-B and new runway construction examples. To implement the significant changes currently envisioned for ATM systems, it will be critical to structure system changes to anticipate and overcome stakeholder disagreements and improve the efficiency of the approval and implementation processes.

2007-07-01T00:00:00Z Lester, Edward Hansman, R. John https://hdl.handle.net/1721.1/37596 2019-04-10T19:32:03Z 2007-06-01T00:00:00Z

Preliminary Analysis of Potential ADS-B User Benefits for Hawaiian Helicopter Air Tour Operators Lester, Edward; Hansman, R. John ADS-B ground infrastructure is currently planned to be installed in Hawaii between 2010 and 2013 as part of the National Airspace System (NAS) wide implementation of ADS-B. Current plans call for ADS-B coverage to be focused on areas of existing radar coverage. However, a large majority of the commercial air tour routes are conducted in regions outside of existing radar coverage due to mountainous terrain and limited radar facilities. The NTSB recommendation would therefore require a change to the ADS-B implementation plans.

2007-06-01T00:00:00Z Hansman, R. John https://hdl.handle.net/1721.1/37324 2019-04-11T10:15:42Z 2005-01-01T00:00:00Z

The Impact of Information Technologies on Air Transportation Hansman, R. John The Air Transportation System and several key subsystems including the Aircraft, Airline, and Air Traffic Management are modeled as interacting control loops. The impact of Information Technologies on each of these subsystems is evaluated through the performance of these control loops. Information technologies are seen to have a significant impact on the safety, efficiency, capability, capacity, environmental impact and financial performance of the Air Transportation System and its components.

2005-01-01T00:00:00Z Idris, Husni Hansman, R. John https://hdl.handle.net/1721.1/37323 2019-04-09T17:16:18Z 2000-11-01T00:00:00Z

Observation and Analysis of Departure Operations at Boston Logan International Airport Idris, Husni; Hansman, R. John The Departure Planner (DP) is a concept for a decision-aiding tool that is aimed at improving the departure operations performance at major congested airports. In order to support the development of the DP tool, the flow constraints and their causalities in the departure process - primarily responsible for generating inefficiencies and delays- need to be identified. This thesis is an effort to identify such flow constraints and gain a deep understanding of the underlying dynamics of the departure process based on field observations and data analysis at Boston Logan International Airport. It was observed that the departure process is a complex interactive queuing system, where aircraft queues form as a manifestation of the flow constraints. While departure delays were observed in all airport components (runways, taxiways, ramps and gates), it was concluded that the flow constraints manifest mainly at the runway system, which exhibits the largest delays and queues. Major delays and inefficiencies were also observed due to downstream flow constraints, which propagate back and block the departure flow from the airport. It was also observed that the airport system is a highly controlled system as the air traffic controllers manage the flow constraints. The air traffic controllers were, therefore, identified as another flow constraint due to their workload and their main strategies in managing the flow constraints were observed. Based on the observations, a core departure process was identified consisting of two main elements: a queuing element generated by the flow constraints and a control element representing the air traffic controller actions. This core process was abstracted using a controlled queuing framework, where the air traffic controller actions are represented by blocking the flow of aircraft in order to maintain safe operation of the airport resources according to the ATC rules and procedures and regulate the outbound flow to constrained downstream resources. The controlled queuing framework was used to analyze the departure process highlighting the queuing dynamics and the control behavior for different flow constraint examples. In conclusion, a number of implications for the Departure Planner and other improved methods for departure operations are inferred from the observations and analysis.

2000-11-01T00:00:00Z Idris, Husni Clarke, John-Paul Bhuva, Rani Kang, Laura https://hdl.handle.net/1721.1/37322 2019-04-12T08:35:04Z 2001-09-01T00:00:00Z

Queuing Model for Taxi-Out Time Estimation Idris, Husni; Clarke, John-Paul; Bhuva, Rani; Kang, Laura Flights incur a large percentage of their delays on the ground during the departure process between their scheduled departure from the gate and takeoff. Because of the large uncertainties associated with them, these delays are difficult to predict and account for, hindering the ability to effectively manage the Air Traffic Control (ATC) system. This paper presents an effort to improve the accuracy of estimating the taxi-out time, which is the duration between pushback and takeoff. The method was to identify the main factors that affect the taxi-out time and build an estimation model that takes the most important ones into account. An analysis conducted at Boston Logan International Airport identified the runway configuration, the airline/terminal, the downstream restrictions and the takeoff queue size as the main causal factors that affect the taxiout time. Of these factors the takeoff queue size was the most important one, where the queue size that an aircraft experienced was measured as the number of takeoffs that took place between its pushback time and its takeoff time. Consequently, a queuing model was built to estimate the taxi-out time at Logan Airport based on queue size estimation. For each aircraft, the queuing model assumes knowledge of the number of departure aircraft present on the airport surface at its pushback time and estimates its takeoff queue size by predicting the amount of passing that it may experience on the airport surface during its taxi out. The prediction performance of the queuing model was compared at Logan Airport to a running average model, which represents the baseline used currently in the Enhanced Traffic Management System (ETMS). The running average model uses a fourteen-day average as the estimate of the taxi-out time. The queuing model improved the mean absolute error in the taxi-out time estimation by approximately twenty percent and the accuracy rate by approximately ten percent, over the fourteen-day running average model.

2001-09-01T00:00:00Z Anagnostakis, Ioannis Idris, Husni R. Clarke, John-Paul Feron, Eric Hansman, R. John Odoni, Amedeo R. Hall, William D. https://hdl.handle.net/1721.1/37321 2019-04-11T10:15:41Z 2000-06-01T00:00:00Z

A Conceptual Design of A Departure Planner Decision Aid Anagnostakis, Ioannis; Idris, Husni R.; Clarke, John-Paul; Feron, Eric; Hansman, R. John; Odoni, Amedeo R.; Hall, William D. Terminal area Air Traffic Management handles both arriving and departing traffic. To date, research work on terminal area operations has focused primarily on the arrival flow and typically departures are taken into account only in an approximate (average) manner. However, arrivals and departures are highly coupled processes especially in the terminal airspace, with complex interactions and sharing of the same airport resources between arrivals and departures taking place in practically every important terminal area. Therefore, the addition of automation aids for departures, possibly in co-operation with existing arrival flow automation systems, could have a profound contribution in enhancing the overall efficiency of airport operations. This paper presents the conceptual system architecture for such an automation aid, the Departure Planner (DP). This architecture can be used as a core in the development of decision-aiding systems to assist air traffic controllers in improving the performance of departure operations and optimize runway time allocation among different operations at major congested airports. The design of such systems is expected to increase the overall efficiency of terminal area operations and yield benefits for all stakeholders involved in Air Traffic Management (ATM) operations, users as well as service providers.

2000-06-01T00:00:00Z Histon, Jonathan M. Hansman, R. John Aigoin, Guillaume Delahaye, Daniel Puechmorel, Stephane https://hdl.handle.net/1721.1/37320 2019-04-12T07:40:32Z 2002-01-01T00:00:00Z

Introducing Structural Considerations into Complexity Metrics Histon, Jonathan M.; Hansman, R. John; Aigoin, Guillaume; Delahaye, Daniel; Puechmorel, Stephane Field observations and focused interviews of Air Traffic Controllers have been used to generate a list of key complexity factors in Air Traffic Control. The underlying structure of the airspace was identified as relevant in many of the factors. A preliminary investigation has revealed that the structure appears to form the basis for abstractions that reduce the difficulty of maintaining Situational Awareness, particularly the projection of future traffic situations. Three examples of such abstractions were identified: standard flows, groupings, and critical points. Preliminary approaches to developing metrics including these structural considerations are discussed.

2002-01-01T00:00:00Z Doble, Nathan Hansman, R. John https://hdl.handle.net/1721.1/37319 2019-04-12T08:35:02Z 2002-10-01T00:00:00Z

Preliminary Design and Evaluation of Portable Electronic Flight Progress Strips Doble, Nathan; Hansman, R. John There has been growing interest in using electronic alternatives to the paper Flight Progress Strip (FPS) for air traffic control. However, most research has been centered on radar-based control environments, and has not considered the unique operational needs of the airport air traffic control tower. Based on an analysis of the human factors issues for control tower Decision Support Tool (DST) interfaces, a requirement has been identified for an interaction mechanism which replicates the advantages of the paper FPS (e.g., head-up operation, portability) but also enables input and output with DSTs. An approach has been developed which uses a Portable Electronic FPS that has attributes of both a paper strip and an electronic strip. The prototype flight strip system uses Personal Digital Assistants (PDAs) to replace individual paper strips in addition to a central management interface which is displayed on a desktop computer. Each PDA is connected to the management interface via a wireless local area network. The Portable Electronic FPSs replicate the core functionality of paper flight strips and have additional features which provide a heads-up interface to a DST. A departure DST is used as a motivating example. The central management interface is used for aircraft scheduling and sequencing and provides an overview of airport departure operations. This paper will present the design of the Portable Electronic FPS system as well as preliminary evaluation results.

2002-10-01T00:00:00Z Bachelder, E. N. Hansman, R. John https://hdl.handle.net/1721.1/37317 2019-04-10T09:59:10Z 1997-04-01T00:00:00Z

Enhanced spatial state feedback for night vision goggle displays Bachelder, E. N.; Hansman, R. John A preliminary study was conducted to investigate the use of visual flow cues as an aid to ground and vertical drift awareness during helicopter flight and targeting while using night vision goggles (NVG's). Three displays were compared: 1) NVG display: simulated NVG image of cockpit and external environment; 2) Overlay display: NVG image with an overlay of a flow cue field and a surrounding wire-frame globe; 3) Cut-out display: same as the Overlay display but with symbology removed from the central region (leaving an unobscured 20 degree field-of-view of the NVG image). Three levels of contrast were also compared using each display type. The visual scenery was displayed to subjects using a helmet-mounted virtual reality device that had a 40 X 50 degree field-of-view liquid crystal display

1997-04-01T00:00:00Z Amar, Marc Hansman, R. John Hannon, Daniel J. Vaneck, Thomas W. Chaudhry, Atif I. https://hdl.handle.net/1721.1/37316 2019-04-12T07:40:32Z 1994-08-01T00:00:00Z

A Human Subject Evaluation of Airport Surface Situational Awareness Using Prototypical Flight Deck Electronic Taxi Chart Displays Amar, Marc; Hansman, R. John; Hannon, Daniel J.; Vaneck, Thomas W.; Chaudhry, Atif I. The advent of Instrument Landing Systems has allowed aircraft to safely takeoff and land in low visibility conditions. However, the lack of a means by which pilots can safely navigate on the ground in poor visibility conditions has been the cause of many runway incursions and several fatal aircraft accidents. Currently flight crews use paper chart depictions of the airport surface and out-the-window visual cues to navigate on the surface. In addition they can be provided some feedback about their position on the surface from ATC. In clear, daylight environmental conditions flight crews can correlate airport features and navigation signs from the out-the-window view with the chart features to maintain airport surface situational awareness. In conditions of fog and darkness however, out-the-window cues are less available and it becomes a difficult task for flight crews to maintain situational awareness. Low visibility conditions also prevent ATC from tracking aircraft position on the airport surface from the tower.

1994-08-01T00:00:00Z Anderson, Kari Carr, Francis Feron, Eric Hall, William https://hdl.handle.net/1721.1/37315 2019-04-12T11:15:03Z 2000-06-01T00:00:00Z

Analysis and Modeling of Ground Operations at Hub Airports Anderson, Kari; Carr, Francis; Feron, Eric; Hall, William Building simple and accurate models of hub airports can considerably help one understand airport dynamics, and may provide quantitative estimates of operational airport improvements. In this paper, three models are proposed to capture the dynamics of busy hub airport operations. Two simple queuing models are introduced to capture the taxi-out and taxi-in processes. An integer programming model aimed at representing airline decision-making attempts to capture the dynamics of the aircraft turnaround process. These models can be applied for predictive purposes. They may also be used to evaluate control strategies for improving overall airport efficiency.

2000-06-01T00:00:00Z Reynolds, Tom G. Histon, Jonathan M. Davison, Hayley J. Hansman, R. John https://hdl.handle.net/1721.1/37314 2019-04-12T11:10:04Z 2002-09-01T00:00:00Z

Structure, Intent & Conformance Monitoring in ATC Reynolds, Tom G.; Histon, Jonathan M.; Davison, Hayley J.; Hansman, R. John In field studies of current Air Traffic Control operations it is found that controllers rely on underlying airspace structure to reduce the complexity of the planning and conformance monitoring tasks. The structure appears to influence the controller’s working mental model through abstractions that reduce the apparent cognitive complexity. These structure-based abstractions are useful for the controller’s key tasks of planning, implementing, monitoring, and evaluating tactical situations. In addition, the structure-based abstractions appear to be important in the maintenance of Situation Awareness. The process of conformance monitoring is analyzed in more detail and an approach to conformance monitoring which utilizes both the structure-based abstractions and intent is presented.

2002-09-01T00:00:00Z Reynolds, Tom G. Hansman, R. John https://hdl.handle.net/1721.1/37313 2019-04-12T08:36:02Z 2002-10-01T00:00:00Z

Conformance Monitoring Approaches in Current and Future Air Traffic Control Environments Reynolds, Tom G.; Hansman, R. John Conformance monitoring is a core task in Air Traffic Control (ATC) operations to determine whether aircraft are adhering to assigned trajectories. This is important for many reasons, including to ensure that tactical collision avoidance maneuvers are properly executed; strategic conflict detection & resolution schemes are valid and security around sensitive locations is maintained. In today’s ATC environment, controllers monitor for conformance via radar systems that primarily provide positional information. As a result, non-conformance criteria are generally based on positional deviations from the assigned trajectory [1] or penetration of restricted airspace such as the No Transgression Zone (NTZ) on PRM approaches [2]. Future ATC surveillance systems such as Automatic Dependant Surveillance (ADS) should provide access to additional aircraft state information which could be used for more effective conformance monitoring. However, at present there is a lack of clear rationale for which states should be surveilled and how they would be used to enable conformance monitoring to be performed at a level appropriate for future operational requirements. This paper describes a framework for this purpose that poses the conformance monitoring task as a model-based fault detection problem.

2002-10-01T00:00:00Z Carr, Francis R. Evans, Anthony Feron, Eric Clarke, John-Paul https://hdl.handle.net/1721.1/37312 2019-04-12T11:10:03Z 2002-10-01T00:00:00Z

Software Tools to Support Research on Airport Departure Planning Carr, Francis R.; Evans, Anthony; Feron, Eric; Clarke, John-Paul A simple, portable and useful collection of software tools has been developed for the analysis of airport surface traffic. The tools are based on a flexible and robust traffic-flow model, and include calibration, validation and simulation functionality for this model. Several different interfaces have been developed to help promote usage of these tools, including a portable Matlab‘ implementation of the basic algorithms; a web-based interface which provides online access to automated analyses of airport traffic based on a database of real-world operations data which covers over 250 U.S. airports over a 5-year period; and an interactive simulation-based tool currently in use as part of a college-level educational module. More advanced applications for airport departure traffic include taxi-time prediction and evaluation of “windowing” congestion control.

2002-10-01T00:00:00Z Frazzoli, E. Mao, Z. H. Oh, J. H. Feron, E. https://hdl.handle.net/1721.1/37311 2019-04-12T11:10:03Z 1999-04-01T00:00:00Z

Resolution of Conflicts Involving Many Aircraft via Semidefinite Programming Frazzoli, E.; Mao, Z. H.; Oh, J. H.; Feron, E. Aircraft conflict detection and resolution is currently attracting the interest of many air transportation service providers and is concerned with the following question: Given a set of airborne aircraft and their intended trajectories, what control strategy should be followed by the pilots and the air traffic service provider to prevent the aircraft from coming too close to each other? This paper addresses this problem by presenting a distributed air-ground architecture, whereby each aircraft proposes its desired heading while a centralized air traffic control architecture resolves any conflict arising between the aircraft involved in the conflict, while minimizing the deviation between desired and conflict-free heading for each aircraft. The resolution architecture relies on a combination of convex programming and randomized searches: It is shown that a version of the planar, multi-aircraft conflict resolution problem that accounts for all possible crossing patterns among aircraft might be recast as a nonconvex, quadratically constrained quadratic program. For this type of problem, there exist efficient numerical relaxations, based on semidefinite programming, that provide lower bounds on the best achievable objective. These relaxations also lead to a random search technique to compute feasible, locally optimal and conflict-free strategies. This approach is demonstrated on numerical examples and discussed.

1999-04-01T00:00:00Z Vakil, Sanjay S. Hansman, R. John https://hdl.handle.net/1721.1/37310 2019-04-12T08:36:02Z 2000-05-01T00:00:00Z

Analysis of Complexity Evolution Management and Human Performance Issues in Commercial Aircraft Automation Systems Vakil, Sanjay S.; Hansman, R. John Autoflight systems in the current generation of aircraft have been implicated in several recent incidents and accidents. A contributory aspect to these incidents may be the manner in which aircraft transition between differing behaviours or “modes.” The current state of aircraft automation was investigated and the incremental development of the autoflight system was tracked through a set of aircraft to gain insight into how these systems developed. This process appears to have resulted in a system without a consistent global representation.

2000-05-01T00:00:00Z Winder, Lee F. Kuchar, James K. https://hdl.handle.net/1721.1/37309 2019-04-09T17:50:18Z 2000-08-01T00:00:00Z

Generalized Philosophy of Alerting with Applications for Parallel Approach Collision Prevention Winder, Lee F.; Kuchar, James K. An alerting system is automation designed to reduce the likelihood of undesirable outcomes that are due to rare failures in a human-controlled system. It accomplishes this by monitoring the system, and issuing warning messages to the human operators when thought necessary to head off a problem. On examination of existing and recently proposed logics for alerting it appears that few commonly accepted principles guide the design process. Different logics intended to address the same hazards may take disparate forms and emphasize different aspects of performance, because each reflects the intuitive priorities of a different designer. Because performance must be satisfactory to all users of an alerting system (implying a universal meaning of acceptable performance) and not just one designer, a proposed logic often undergoes significant piecemeal modification before gaining general acceptance. This report is an initial attempt to clarify the common performance goals by which an alerting system is ultimately judged. A better understanding of these goals will hopefully allow designers to reach the final logic in a quicker, more direct and repeatable manner. As a case study, this report compares three alerting logics for collision prevention during independent approaches to parallel runways, and outlines a fourth alternative incorporating elements of the first three, but satisfying stated requirements.

2000-08-01T00:00:00Z Ageeva, Yana Clarke, John-Paul https://hdl.handle.net/1721.1/37308 2019-04-10T09:58:59Z 2000-08-01T00:00:00Z

Approaches to Incorporating Robustness into Airline Scheduling Ageeva, Yana; Clarke, John-Paul The airline scheduling process used by major airlines today aims to develop opti- mal schedules which maximize revenue. However, these schedules are often far from \optimal" once deployed in the real world because they do not accurately take into account possible weather, air tra c control (ATC), and other disruptions that can occur during operation. The resulting ight delays and cancellations can cause sig- ni cant revenue loss, not to mention service disruptions and customer dissatisfaction. A novel approach to addressing this problem is to design schedules that are robust to schedule disruptions and can be degraded at any airport location or in any region with minimal impact on the entire schedule. This research project suggests new methods for creating more robust airline schedules which can be easily recovered in the face of irregular operations. We show how to create multiple optimal solutions to the Aircraft Routing problem and suggest how to evaluate robustness of those solutions. Other potential methods for increasing robustness of airline schedules are reviewed.

2000-08-01T00:00:00Z Davison, Hayley Hansman, R. John https://hdl.handle.net/1721.1/37296 2019-04-05T16:17:11Z 2001-06-01T00:00:00Z

Identification of Communication and Coordination Issues in the U. S. Air Traffic Control System Davison, Hayley; Hansman, R. John Today’s air traffic control system is approaching the point of saturation, as evidenced by increasing delays across the National Airspace System (NAS). There exists an opportunity to enhance NAS efficiency and reduce delays by improving strategic communication throughout the ATC system. Although several measures have been taken to improve communication (e.g., Collaborative Decision Making tools), communication issues between ATC facilities remain. It is hypothesized that by identifying the key issues plaguing inter-facility strategic communication, steps can be taken to enhance these communications, and therefore ATC system efficiency.

2001-06-01T00:00:00Z Lyne, Lisette https://hdl.handle.net/1721.1/37295 2019-04-08T08:07:58Z 2001-07-01T00:00:00Z

Recommended Practices for Human Factors Evaluation Development Process for Advanced Avionics Lyne, Lisette Advanced avionic systems are currently being developed for use in general aviation aircraft. The avionics include both primary flight displays and multi-functional displays. In order to support the human factors development of such displays, a research project was undertaken to review current FAA guidelines relating to human factors requirements necessary for certification, and other relevant FAA documentation. FAR Part 23 is commonly used for certifying avionics for general aviation aircraft. Specifically, Part 23 is used for normal, utility, acrobatic, and commuter category aircraft. Part 23 was reviewed and the human factors requirements listed in this document. The human factors requirements are presented in the regulations in very general terms, and focus primarily on presentation of warning information, location of instruments, visibility of instruments, pilot workload, and warning, caution, and advisory light color schemes. Little guidance is given in the regulations on how to measure, test and satisfy the human factors related regulations.

2001-07-01T00:00:00Z Melconian, Terran Clarke, John-Paul https://hdl.handle.net/1721.1/37294 2019-04-09T16:12:10Z 2001-09-01T00:00:00Z

Effects of Increased Nonstop Routing on Airline Cost and Profit Melconian, Terran; Clarke, John-Paul Delays in the United States air transportation industry are increasing every year, with correspondingly increasing costs. Delays are particularly bad at hub airports, due to the extra demand placed on these connecting points. This paper addresses one approach to help alleviate this problem, that of shifting capacity from hub-and-spoke flights to nonstop flights. In order to evaluate the effects of such a change, we analyze the market share and revenue benefits of adding new nonstop flights to a market previously served only by connecting service, and examine the actual cost of delays. The MIT Extensible Air Network Simulation, developed in support of this work, is also presented. For a sample analysis for Continental Airlines, it is found that over $550,000 per day in additional profit could be obtained by reassigning flights away from the congested hubs.

2001-09-01T00:00:00Z Downen, Troy Hansman, R. John https://hdl.handle.net/1721.1/37293 2019-04-12T08:06:28Z 2002-02-01T00:00:00Z

Analysis of Barriers to the Utility of General Aviation Based on a User Survey and Mode Choice Model Downen, Troy; Hansman, R. John General aviation is an underutilized transportation mode, particularly when compared to alternative modes such as the automobile and the commercial airlines. In this research, barriers to the utility of general aviation were identified through a web-based survey of active general aviation pilots, with 1,471 surveys returned and suitable for analysis. The survey data indicated five key barriers which were thought by pilots to be currently reducing their ability to utilize general aviation transportation to its fullest extent: weather, expense of the travel mode, a lack of mobility at the destination, doorstep-to-destination travel time, and reduced access to general aviation transportation.

2002-02-01T00:00:00Z Histon, Jonathan https://hdl.handle.net/1721.1/37292 2019-04-12T07:40:31Z 2002-06-01T00:00:00Z

The Impact of Structure on Cognitive Complexity in Air Traffic Control Histon, Jonathan Focused interviews with air traffic controllers and traffic management unit personnel, as well as analysis of traffic flow patterns based on Enhanced Traffic Management System (ETMS) data, suggest that controllers rely on underlying airspace structure to reduce the cognitive complexity of managing an air traffic control situation. To understand how structural elements reduce cognitive complexity, a framework has been developed relating structure, situation awareness, and a controller’s working mental model. It is hypothesized that structure forms the basis for abstractions which simplify a controller’s working mental model. The working mental model is used to support the key tasks of a controller identified by Pawlak (1996): planning, implementing, monitoring, and evaluating. Three examples of structure-based abstractions have been identified: standard flows, groupings, and critical points.

2002-06-01T00:00:00Z Vigeant-Langlois, Laurence N. Hansman, R. John https://hdl.handle.net/1721.1/36370 2019-04-10T09:59:02Z 2000-02-01T00:00:00Z

Cockpit Weather Information System Requirements for Flight Operations in Icing Conditions Vigeant-Langlois, Laurence N.; Hansman, R. John In order to support the development of remote sensing technologies, the requirements of cockpit information systems for flight operations in icing conditions were investigated. Pilot information needs were investigated in a web-based survey. Results identified important information elements, frequently used information paths for obtaining icing-related information, and data on significant icing encounters and key icing-related information and decision criteria. In addition, the influence of potential ice detection system features on pilot decision-making was investigated in a web-based experiment. Results showed that the use of graphical displays improved pilot decision-making over existing text-based icing information. The use of vertical view was found to support better decision-making. Range enhancement was not found to have strong positive influence; however the minimum range tested was 25 nautical miles, which may be in excess of current technical capabilities. The depiction of multiple icing severity levels was not found to be as important as accurate information on the location of icing conditions. This may have significant impact for remote sensing and forecasting efforts currently under way, as the technical challenges for accurate detection of icing presence may be significantly inferior to those of accurate detection of multiple icing severity levels.

2000-02-01T00:00:00Z Kaliardos, William N. Hansman, R. John https://hdl.handle.net/1721.1/36369 2019-04-14T06:59:45Z 1999-09-01T00:00:00Z

Semi-Structured Decision Processes: A Conceptual Framework for Understanding Human-Automation Decision Systems Kaliardos, William N.; Hansman, R. John The purpose of this work is to improve understanding of existing and proposed decision systems, ideally to improve the design of future systems. A "decision system" is defined as a collection of information-processing components -- often involving humans and automation (e.g., computers) -- that interact towards a common set of objectives. Since a key issue in the design of decision systems is the division of work between humans and machines (a task known as "function allocation"), this report is primarily intended to help designers incorporate automation more appropriately within these systems. This report does not provide a design methodology, but introduces a way to qualitatively analyze potential designs early in the system design process. A novel analytical framework is presented, based on the concept of "semi-Structured" decision processes. It is believed that many decisions involve both well-defined "Structured" parts (e.g., formal procedures, traditional algorithms) and ill-defined "Unstructured" parts (e.g., intuition, judgement, neural networks) that interact in a known manner. While Structured processes are often desired because they fully prescribe how a future decision (during "operation") will be made, they are limited by what is explicitly understood prior to operation. A system designer who incorporates Unstructured processes into a decision system understands which parts are not understood sufficiently, and relinquishes control by deferring decision-making from design to operation. Among other things, this design choice tends to add flexibility and robustness. The value of the semi-Structured framework is that it forces people to consider system design concepts as operational decision processes in which both well-defined and ill-defined components are made explicit. This may provide more insight into decision systems, and improve understanding of the implications of design choices. The first part of this report defines the semi-Structured process and introduces a diagrammatic notation for decision process models. In the second part, the semi-Structured framework is used to understand and explain highly evolved decision system designs (these are assumed to be representative of "good" designs) whose components include feedback controllers, alerts, decision aids, and displays. Lastly, the semi-Structured framework is applied to a decision system design for a mobile robot.

1999-09-01T00:00:00Z Kornfeld, Richard P. Hansman, R. John Deyst, John J. https://hdl.handle.net/1721.1/36368 2019-04-12T07:40:30Z 1999-06-01T00:00:00Z

The Impact of GPS Velocity Based Flight Control on Flight Instrumentation Architecture Kornfeld, Richard P.; Hansman, R. John; Deyst, John J. This thesis explores the use of velocity information obtained by a Global Positioning System (GPS) receiver to close the aircraft’s flight control loop. A novel framework to synthesize attitude information from GPS velocity vector measurements is discussed. The framework combines the benefits of high-quality GPS velocity measurements with a novel velocity vector based flight control paradigm to provide a means for the human operator or autopilot to close the aircraft flight control loop. Issues arising from limitations in GPS as well as the presence of a human in the aircraft control loop are addressed. Results from several flight tests demonstrate the viability of this novel concept and show that GPS velocity based attitude allows for equivalent aircraft control as traditional attitude. Two possible applications of GPS velocity based attitude, an autopilot and a tunnelin- the-sky trajectory guidance system, are demonstrated in flight. Unlike traditional autopilot and trajectory guidance systems, these applications rely solely on the information obtained from a single-antenna GPS receiver which makes them affordable to the larger General Aviation aircraft community. Finally, the impact of GPS velocity based flight control on the instrumentation architecture of flight vehicles is investigated.

1999-06-01T00:00:00Z Farley, Todd C. Hansman, R. John https://hdl.handle.net/1721.1/36367 2019-04-09T18:52:44Z 1999-01-01T00:00:00Z

An Experimental Study of the Effect of Shared Information on Pilot/Controller Re-Route Negotiation Farley, Todd C.; Hansman, R. John Air–ground data link systems are being developed to enable pilots and air traffic controllers to share information more fully. The sharing of information is generally expected to enhance their shared situation awareness and foster more collaborative decision making. An exploratory, part-task simulator experiment is described which evaluates the extent to which shared information may lead pilots and controllers to cooperate or compete when negotiating route amendments. The results indicate an improvement in situation awareness for pilots and controllers and a willingness to work cooperatively. Independent of data link considerations, the experiment also demonstrates the value of providing controllers with a good-quality weather representation on their plan view displays. Observed improvements in situation awareness and separation assurance are discussed. It is argued that deployment of this relatively simple, low-risk addition to the plan view displays be accelerated.

1999-01-01T00:00:00Z Endsley, Mica R. Farley, Todd C. Jones, William M. Midkiff, Alan H. Hansman, R. John https://hdl.handle.net/1721.1/35929 2019-04-11T10:45:52Z 1998-09-01T00:00:00Z

Situation Awareness Information Requirements For Commercial Airline Pilots Endsley, Mica R.; Farley, Todd C.; Jones, William M.; Midkiff, Alan H.; Hansman, R. John Situation awareness is presented as a fundamental requirement for good airmanship, forming the basis for pilot decision making and performance. To develop a better understanding of the role of situation awareness in flying, an analysis was performed to determine the specific situation awareness information requirements for commercial aircraft pilots. This was conducted as a goal-directed task analysis in which pilots' major goals, subgoals, decisions and associated situation awareness information requirements were delineated based on elicitation from experienced commercial airline pilots. A determination of the major situation awareness information requirements for visual and instrument flight was developed from this analysis, providing a foundation for future system development which seeks to enhance pilot situation awareness and provide a basis for the development of situation awareness measures for commercial flight.

1998-09-01T00:00:00Z Dershowitz, Adam L. Hansman, R. John https://hdl.handle.net/1721.1/35928 2019-04-12T08:35:52Z 0097-10-01T00:00:00Z

The Effect Of Options On Pilot Decision Making In The Presence Of Risk Dershowitz, Adam L.; Hansman, R. John An Option-Based Decision Framework is developed. This Framework may be applied to decisions that must be made in the face of high risk. The work is motivated by the needs of decision makers, specifically aviation decision makers. A survey of pilots was completed and demonstrates that these decision makers feel that knowledge of which options are available is important to them when they are facing high risk situations. The Option-Based Decision Framework (OBDF) is developed and is applied to decision making and is used to define what is called “Decision Space” that may be used to make decisions and to understand the information needs of decision makers. Decision makers are not able to accurately assess small probabilities however it is assumed that they are able to assess hazard and option probabilities into general categories. This categorization is used to define decision guidance rules for decision makers. In order to demonstrate its use the OBDF is applied to an experiment. Finally the Framework is applied to some examples, and the implications of the Option-Based Decision Framework are discussed. The Option-Based Decision Framework offers insight into the decision process. Although it is a static model, the general understanding may be applied to both static and dynamic decisions. The OBDF demonstrates how options have the effect of mitigating risk due to the presence of a Catastrophic End State. Thus, options maybe used to increase the safety to decision makers. The Framework may be used to understand the information needs of decision makers, to define procedures, to understand judgment, and to help train decision makers.

0097-10-01T00:00:00Z Barhydt, Richard https://hdl.handle.net/1721.1/35915 2019-04-10T09:58:54Z 1997-05-01T00:00:00Z

Experimental Studies of the Effect of Intent Information on Barhydt, Richard Intent information provides knowledge of another aircraft’s current and future trajectory states. Prototype traffic displays were designed for four different levels of intent: Position, Rate, Commanded State, and FMS-Path. The current TCAS Display, which shows altitude rate in addition to current position and altitude, was used as a baseline and represents the lowest level of intent. The Rate, Commanded State, and FMS-Path Displays show increasing levels of intent information using TCAS-like symbology in addition to incorporating a conflict probe and profile view display. An initial experiment was run on the MIT Part Task Flight Simulator in which eight airline pilots flew five traffic scenarios with each of the four displays. Results show that pilots had fewer separation violations and maneuvered earlier with the three intent displays. Separation violations were reduced when pilots maneuvered earlier. A second experiment was run to compare performance between displaying intent information directly and incorporating it into a conflict probe. A different set of eight airline pilots flew four traffic scenarios with the TCAS and Commanded State Displays with and without the conflict probe. Conflict probes with two minute and long range look-ahead times were tested. Displaying conflict bands or showing intent information directly both led to fewer separation violations and earlier avoidance maneuvers than the base TCAS Display. Performance was similar between the two minute and long range look-ahead conflict probes. Pilots preferred all intent displays over the TCAS Display.

1997-05-01T00:00:00Z Vakil, Sanjay S. Midkiff, Alan H. Hansman, R. John https://hdl.handle.net/1721.1/35914 2019-04-12T08:35:51Z 1996-06-01T00:00:00Z

Development and Evaluation of an Electronic Vertical Situation Display Vakil, Sanjay S.; Midkiff, Alan H.; Hansman, R. John Current advanced commercial transport aircraft, such as the Boeing B777/B747-400, the Airbus A320/A340 and the McDonnell Douglas MD-11, rely on AutoFlight Systems (AFS) for flight management, navigation and inner loop control. These systems have evolved from straightforward autopilots into multiple computers capable of sophisticated and interrelated tasks. These tasks span the range from high level flight management to low level inner loop control. In addition, these systems provide envelope protection to prevent pilots from committing mistakes such as stalling the aircraft or lowering flaps at high speeds. Unfortunately, as these systems have become more complex and interconnected, a new class of problems has developed associated with pilots’ interaction with the automation. Many incidents have been reported where there exists some confusion between the pilots’ expectations of the AFS and what the system is actually doing (Corwin, 1995). This confusion has been termed a Mode Awareness Problem (MAP). After a description of the AFS, a formal definition of mode awareness problems is presented in Section 1.3 followed by representative incidents in which mode awareness problems are suspected as being a contributory factor.

1996-06-01T00:00:00Z Johnson, Eric N. Pritchett, Amy R. https://hdl.handle.net/1721.1/35913 2019-04-11T11:07:02Z 1995-03-01T00:00:00Z

Experimental Study of Vertical Flight Path Mode Awareness Johnson, Eric N.; Pritchett, Amy R. An experimental simulator study was run to test pilot detection of an error in autopilot mode selection. Active airline air crew were asked to fly landing approaches by commanding the Flight Path Angle mode while monitoring the approach with both a Head Up Display and Head Down Displays. During one approach, the Vertical Speed mode was intentionally triggered by an experimenter instead, causing a high rate of descent below the intended glide path. Of the 12 pilots, 10 were unable to detect the high descent rate prior to significant glide path deviation.

1995-03-01T00:00:00Z Prechtl, Eric Frederick https://hdl.handle.net/1721.1/35912 2019-04-12T08:35:51Z 1994-04-24T00:00:00Z

Development of a Piezoelectric Servo-Flap Actuator for Helicopter Rotor Control Prechtl, Eric Frederick An actuator using a piezoelectric bender to de ect a trailing edge servo- ap for use on a helicopter rotor blade was designed, built, and tested. This actuator is an improvement over one developed previously at MIT. The design utilizes a new exure mechanism to connect the piezoelectric bender to the control surface. The e ciency of the bender was improved by tapering its thickness properties with length. Also, implementation of a nonlinear circuit allowing the application of a greater range of actuator voltages increased the resultant strain levels. Experiments were carried out on the bench top to determine the frequency response of the actuator, as well as hinge moment and displacement capabilities. Flap de ections of 11.5 deg were demonstrated while operating under no load conditions at 10 Hz. Excessive creep at low frequencies precluded the measurement of achievable hinge moments, but extrapolation from de ection and voltage characteristics indicate that if properly scaled, the present actuator will produce ap de ections greater than 5 deg at the 90% span location on an operational helicopter. In addition, the rst mode of the actuator was at seven times the rotational frequency (7/rev) of the target model scale rotor. Proper inertial scaling of this actuator could raise this modal frequency to 10/rev on an operational helicopter, which is adequate for most rotor control purposes. A linear state space model of the actuator was derived. Comparisons of this model with the experimental data highlighted a number of mild nonlinearities in the actuator's response. However, the agreement seen between the experiment and analysis indicate that the model is a valid tool for predicting actuator response.

1994-04-24T00:00:00Z Vigeant-Langlois, Laurence Hansman, R. John https://hdl.handle.net/1721.1/35887 2019-04-12T08:35:50Z 2003-06-16T00:00:00Z

Implications of Contingency Planning Support for Weather and Icing Vigeant-Langlois, Laurence; Hansman, R. John A human-centered systems analysis was applied to the adverse aircraft weather encounter problem in order to identify desirable functions of weather and icing information. The importance of contingency planning was identified as emerging from a system safety design methodology as well as from results of other aviation decision-making studies. The relationship between contingency planning support and information on regions clear of adverse weather was investigated in a scenariobased analysis. A rapid prototype example of the key elements in the depiction of icing conditions was developed in a case study, and the implications for the components of the icing information system were articulated.

2003-06-16T00:00:00Z Tam, Ryan Hansman, R. J. https://hdl.handle.net/1721.1/35886 2019-04-10T09:58:53Z 2003-07-01T00:00:00Z

Air Transportation And Socioeconomic Connectivity In The United States Since Deregulation Tam, Ryan; Hansman, R. J. In light of ongoing threats to the viability of traditional airline business models and the provision of air service in the United States, this paper studies the fundamental interdependence of the national economy and the air transportation system. A conceptual framework has been developed to identify the mechanisms that enable air transportation to shape regional economic productivity and social connectivity. Regional economic census data is combined with airline traffic and financial data to illustrate the changes in supply and demand for air travel after the deregulation of the airline industry in 1978. The paper focuses on how the utilization of air transportation system supports economic and social activities across greater distances than would otherwise be possible—changing the economic geography of market access. An analysis of industry restructuring after the economic bubble and the attacks of September 11, 2001 are also used to look at the potential impacts on economic activity at the regional and national levels.

2003-07-01T00:00:00Z Tam, Ryan Hansman, R. John https://hdl.handle.net/1721.1/35885 2019-04-10T09:58:53Z 2003-05-01T00:00:00Z

An Analysis of the Dynamics of the US Commercial Air Transportation System Tam, Ryan; Hansman, R. John Major trends in the airline industry are analyzed to highlight key dynamics that govern the US domestic air transportation system. The hypothesis is that air travel supply and demand equilibriums, a reliance on outside capital, and intra-industry competition are among the most critical forces that are driving the current restructuring of the airline industry. Data on airline operational and financial performance is used to trace these dynamics as the industry evolved through periods of industry deregulation, an economic growth bubble, and the aftermath of the attacks of September 11, 2001. The thesis identifies the post-deregulation development of hub-and-spoke networks and yield management systems as the key forces that would set the stage for a bifurcation of the air travel market during a cycle of economic growth in the late 1990’s. During this bubble economy, the dynamics of supply and demand fundamentally shifted as the major carriers focused on high-revenue, high-cost operations and travelers began to flock to newer low-fare, low-cost carriers. With the end of the economic growth cycle in 2000, the bifurcation of the airline industry began to affect revenues and profits at the major carriers. Massive and unprecedented industry losses would ensue, and would be compounded by the attacks of 9/11. Airline operational strategies in response to 9/11 and longer-term restructuring efforts are discussed in order to further identify the key dynamics affecting the air transportation system. These dynamics are synthesized and then discussed within the broader context of the air transportation system, the impact of air travel on the economy and mobility, and the role of government.

2003-05-01T00:00:00Z Tam, Ryan Hansman, R. J. https://hdl.handle.net/1721.1/35884 2019-04-12T08:35:50Z 2002-10-01T00:00:00Z

Impact of Air Transportation on Regional Economic and Social Connectivity in the United States Tam, Ryan; Hansman, R. J. This paper identifies some of the forces that influence the impact of air transportation on regional connectivity and economic productivity in the United States. In light of recent threats to the financial viability of the airline industry, a conceptual model has been developed to highlight the interdependence of the national economy and the air transportation system. These complex relationships are identified using regional economic and social indicators combined with airline traffic and financial data. The changes in supply and demand for air travel after the deregulation of the airline industry in 1978—as well as the challenges faced after the attacks of September 11, 2001—are used to frame this discussion.

2002-10-01T00:00:00Z Reynolds, T. G. Hansman, R. J. https://hdl.handle.net/1721.1/35882 2019-04-12T08:35:50Z 2003-11-01T00:00:00Z

Investigating Conformance Monitoring Issues in Air Traffic Control Using Fault Detection Approaches Reynolds, T. G.; Hansman, R. J. In order to maintain Air Traffic Control (ATC) system safety, security and efficiency, conformance monitoring must be performed to ensure that aircraft adhere to their assigned clearances. New Decision Support Tools (DSTs), coupled to advanced communication, navigation and surveillance technologies are being developed which may enable more effective conformance monitoring to be undertaken relative to today. However, there are currently no general analysis techniques to help identify fundamental conformance monitoring issues and more effective approaches that new DSTs should employ. An approach to address this need is presented in this work that draws parallels between ATC conformance monitoring and general system fault detection, allowing fault detection methods developed for other domains to be employed for this new application. The resulting Conformance Monitoring Analysis Framework provides a structure to research conformance monitoring issues and approaches. Detailed discussions are presented for each of the elements of the framework, including the Conformance Basis, Actual System Representation, Conformance Monitoring Model, Conformance Residual Generation and Decision-Making components. Flight test data during a simple lateral non-conformance maneuver was used to demonstrate various implementation options of the framework. Application of the framework for ATC conformance monitoring research was demonstrated using flight test and simulator data in various operational and surveillance environments. Key findings in the lateral, vertical and longitudinal domains during non-transitioning and transitioning flight regimes are presented. In general, it was found that more effective conformance monitoring can be conducted relative to existing systems in the non-transitioning environments when advanced surveillance systems provide higher accuracy, higher update rate and higher order dynamic state information for use in more sophisticated DST algorithms. This is contrasted to the significantly greater conformance monitoring challenges that exist in the transitioning regimes due to Conformance Basis and modeling uncertainties. These challenges can be handled through the use of procedural design, higher fidelity modeling techniques or the surveillance of intent states. Two extended applications of the framework are also presented: a method for intent inferencing to determine what alternative trajectory a non-conforming aircraft may be following and a technique for environmental parameter estimation.

2003-11-01T00:00:00Z Mozdzanowska, A. Hansman, R. J. Histon, J. Delahaye, D. https://hdl.handle.net/1721.1/35881 2019-04-12T08:35:49Z 2003-06-27T00:00:00Z

Emergence of Regional Jets and The Implications on Air Traffic Management Mozdzanowska, A.; Hansman, R. J.; Histon, J.; Delahaye, D. Airlines are increasingly using regional jets to better match aircraft size to high value, but limited demand markets. This has been especially important following increased financial pressure on the industry after September 11th 2001. The increase in regional jets represents a significant change from traditional air traffic patterns. To investigate the possible impacts of this change, this study analyzed the emerging flight patterns and performance of regional jets compared to traditional jets and turboprops. In addition, a comparison between regional jet flight patterns in the United States and Europe was conducted. Regional jet operations generally cluster in the regions with high traditional jet operation density, implying a high level of interaction between the two aircraft types. The regional jets were observed to fly shorter routes than traditional jets, with few transcontinental flights. However, the gap between regional and narrow body traditional jet stage lengths appears to be closing. In addition, regional jets were observed to exhibit lower climb rates than traditional jets, which may impact air traffic control handling and sector design. It was also observed that regional jets cruise at lower altitudes than traditional jets possibly due to their shorter flight routes. Finally, it was observed that regional jets cruise at a lower Mach number than traditional jets, except on specific high density routes where the regional jets are either slowing down the traditional jet traffic or flying above their optimum cruise speed. Since the composition and utilization of the national fleet is changing, this will pose potential problems for air traffic management. In particular, it may cause serious congestion issues when demand increases during an economic recovery.

2003-06-27T00:00:00Z Mozdzanowska, A. Hansman, R. J. https://hdl.handle.net/1721.1/35865 2019-04-10T09:58:54Z 2003-07-01T00:00:00Z

Observations and Potential Impacts of Regional Jet Operating Trends Mozdzanowska, A.; Hansman, R. J. Airlines are increasingly using regional jets to better match aircraft size to high value demand markets, and reduce labor costs. This has been especially important due to the increased pressure on the industry following September 11th 2001, because airlines see regional jets as a major part of their financial recovery plan. The increase in regional jets represents a significant change from traditional air traffic patterns and airline business models. To investigate the possible impacts of this change, this study analyzed the economic characteristics of regional jets, and well as the emerging flight patterns and performance of regional jets compared to traditional jets and turboprops. It was found that regional airlines have lower crew costs per number of block hours and take offs, but higher crew cost per ASMs and RPMs. As a result, the revenues at regional airlines are more susceptible to changes in crew cost. It was also observed that regional jets operate differently then traditional jets. Regional jets increase the number of operations at airports and in the take off tracks around airports, which may result in increased congestion. Regional jets were also observed to exhibit lower climb rates than traditional jets, which may negatively impact air traffic control handling and sector design. Given the possible economic and operational problems associated with regional jets, their growth may pose unanticipated problems.

2003-07-01T00:00:00Z Lohrenz, Maura https://hdl.handle.net/1721.1/35820 2019-04-10T09:58:47Z 2003-06-01T00:00:00Z

Cognitive Issues Related to Advanced Cockpit Displays: Supporting the Transition Between Lohrenz, Maura A critical issue in military aviation is the pilot’s ability to transition between primarily internal (head-down, instrument-driven) and external (head-up, out of the cockpit) guidance. Experimental cockpit displays were designed and tested for how well they might support this transition phase for military pilots performing time-critical air-to-ground targeting missions such as Forward Air Control and Close Air Support. Twelve subjects performed three sets of experiments using a flight simulator (with simulated heads-up display in the forward field of view) connected to a moving-map display. The experiments were designed to help explain which visual cues in the displays might best help a pilot 1) navigate to a given target area (the “flight guidance” phase of a mission) and 2) search for, find and identify a target (the “target acquisition” phase).

2003-06-01T00:00:00Z Jiang, H. Ren, L. Hansman, R. J. https://hdl.handle.net/1721.1/35819 2019-04-12T08:35:45Z 2003-11-17T00:00:00Z

Market and Infrastructure Analysis of Future Air Cargo Demand in China Jiang, H.; Ren, L.; Hansman, R. J. This paper describes an analysis of future air cargo demand in China and its implications for system infrastructure. By extrapolating current trends and evaluating government policies, China is projected to achieve sustained economic development over the next 20 years. Based on this assumption, a forecast for future air cargo demand is made for the period through 2020 using econometric methods. The forecast projects air cargo traffic growth at 11.2% per annum, expanding more than seven fold by 2020 – resulting in an expected 27 million tonnes cargo throughput originating from Chinese airports. A baseline forecast for the cargo throughput at the major hubs and large airports in mainland China, Hong Kong and Taiwan is presented.

2003-11-17T00:00:00Z Miller, Bruno Clarke, John-Paul https://hdl.handle.net/1721.1/35818 2019-04-10T09:58:47Z 2003-06-10T00:00:00Z

The hidden value of air transportation infrastructure Miller, Bruno; Clarke, John-Paul Air transportation is a key strategic asset in that it provides access to markets and thereby enables the economic development of nations. Thus, in order to maintain their competitiveness in a global economy, countries must invest in air transportation infrastructure to ensure their ability to meet current and future demand for aviation services. The objective of this paper is to develop and illustrate a methodology for evaluating the strategic value of air transportation infrastructure, in particular the benefits associated with the ability to react quickly to changes in the market. The hypothesis is that by recognizing and taking advantage of this strategic value, it may be possible to design better policies for aviation infrastructure delivery.

2003-06-10T00:00:00Z Doble, Nathan Hansman, R. John https://hdl.handle.net/1721.1/35817 2019-04-10T09:58:50Z 2003-06-01T00:00:00Z

Design And Evaluation Of A Portable Electronic Flight Progress Strip System Doble, Nathan; Hansman, R. John There has been growing interest in using electronic alternatives to the paper Flight Progress Strip (FPS) for air traffic control. However, most research has been centered on radar-based control environments, and has not considered the unique operational needs of the airport air traffic control tower. Based on an analysis of the human factors issues for control tower Decision Support Tool (DST) interfaces, a requirement has been identified for an interaction mechanism which replicates the advantages of the paper FPS (e.g., minimal head-down time, portability) but also enables input and output with DSTs. An approach has been developed which uses a Portable Electronic FPS that has attributes of both a paper flight strip and an electronic flight strip. The prototype Portable Electronic Flight Progress Strip system uses handheld computers to replace individual paper strips in addition to a central management interface which is displayed on a desktop computer. Each electronic FPS is connected to the management interface via a wireless local area network. The Portable Electronic FPSs replicate the core functionality of paper flight strips and have additional features which provide an interface to a DST. A departure DST is used as a motivating example. This report presents the rationale for a Portable Electronic FPS system and discusses the formatting and functionalities of the prototype displays. A usability study has been conducted to determine the utility of the Portable Electronic FPS in comparison to paper flight strips. This study consisted of a human-in-the-loop experiment which simulated the tasks of an air traffic controller in an airport control tower environment. Specific issues explored during the experiment include the appropriateness of displaying departure advisories on the Portable Electronic FPS, the importance of FPS portability, and the advantages of interaction mechanisms enabled by an electronic interface. Experimental results are presented which show that test subjects preferred the Portable Electronic FPS to a paper FPS. However, results for performance-based measures were partially confounded by a dominance of practice effects, experimental limitations, and characteristics of the prototype hardware itself. The implications of the experimental results are discussed with the aim of directing further research toward the goal of creating an operationally-deployable Portable Electronic FPS system. Future research should explore emergent display technologies which better emulate the physical characteristics of the paper FPS. Once this is accomplished, higher-fidelity performance-based analyses may be conducted, engaging air traffic controllers on design and implementation issues.

2003-06-01T00:00:00Z Davison, H. J. Hansman, R. J. https://hdl.handle.net/1721.1/35816 2019-04-12T08:35:44Z 2003-01-01T00:00:00Z

Supporting the Future Air Traffic Control Projection Process Davison, H. J.; Hansman, R. J. In air traffic control, projecting what the air traffic situation will be over the next 30 seconds to 30 minutes is a key process in identifying conflicts that may arise so that evasive action can be taken upon discovery of these conflicts. A series of field visits in the Boston and New York terminal radar approach control (TRACON) facilities and in the oceanic air traffic control facilities in New York and Reykjavik, Iceland were conducted to investigate the projection process in two different ATC domains. The results from the site visits suggest that two types of projection are currently used in ATC tasks, depending on the type of separation minima and/or traffic restriction and information display used by the controller. As technologies improve and procedures change, care should be taken by designers to support projection through displays, automation, and procedures. It is critical to prevent time/space mismatches between interfaces and restrictions. Existing structure in traffic dynamics could be utilized to provide controllers with useful behavioral models on which to build projections. Subtle structure that the controllers are unable to internalize could be incorporated into an ATC projection aid.

2003-01-01T00:00:00Z Davison, H. J. Histon, J. M. Ragnarsdottir, M. D. Major, L. M. Hansman, R. J. https://hdl.handle.net/1721.1/35814 2019-04-10T09:58:46Z 2003-06-23T00:00:00Z

Impact of Operating Context on the Use of Structure in Air Traffic Controller Cognitive Processes Davison, H. J.; Histon, J. M.; Ragnarsdottir, M. D.; Major, L. M.; Hansman, R. J. This paper investigates the influence of structure on air traffic controllers’ cognitive processes in the TRACON, En Route, and Oceanic environments. Radar data and voice command analyses were conducted to support hypotheses generated through observations and interviews conducted at the various facilities. Three general types of structure-based abstractions (standard flows, groupings, and critical points) have been identified as being used in each context, though the details of their application varied in accordance with the constraints of the particular operational environment. Projection emerged as a key cognitive process aided by the structure-based abstractions, and there appears to be a significant difference between how time-based versus spatial-based projection is performed by controllers. It is recommended that consideration be given to the value provided by the structure-based abstractions to the controller as well as to maintain consistency between the type (time or spatial) of information support provided to the controller.

2003-06-23T00:00:00Z Davison, H. J. Hansman, R. J. https://hdl.handle.net/1721.1/35812 2019-04-10T09:58:46Z 2003-03-01T00:00:00Z

Use of Structure as a Basis for Abstraction in Air Traffic Control Davison, H. J.; Hansman, R. J. The safety and efficiency of the air traffic control domain is highly dependent on the capabilities and limitations of its human controllers. Past research has indicated that structure provided by the airspace and procedures could aid in simplifying the controllers cognitive tasks. In this paper, observations, interviews, voice command data analyses, and radar analyses were conducted at and using data from the Boston Terminal Route Control (TRACON) facility to determine if there was evidence of controllers using structure to simplify their cognitive processes. The data suggest that controllers do use structure-based abstractions to simplify their cognitive processes, particularly the projection task. These structure-based abstractions were outlined and their effect on various ATC cognitive processes were discussed. Suggestions for the design of future ATC information tools were provided based on the findings from this study.

2003-03-01T00:00:00Z Winder, Lee F. Kuchar, James K. https://hdl.handle.net/1721.1/35763 2019-04-10T09:58:38Z 2004-08-01T00:00:00Z

Hazard Avoidance Alerting With Markov Decision Processes Winder, Lee F.; Kuchar, James K. This thesis describes an approach to designing hazard avoidance alerting systems based on a Markov decision process (MDP) model of the alerting process, and shows its benefits over standard design methods. One benefit of the MDP method is that it accounts for future decision opportunities when choosing whether or not to alert, or in determining resolution guidance. Another benefit is that it provides a means of modeling uncertain state information, such as knowledge about unmeasurable mode variables, so that decisions are more informed. A mode variable is an index for distinct types of behavior that a system exhibits at different times. For example, in many situations normal system behavior is safe, but rare deviations from the normal increase the likelihood of a harmful incident. Accurate modeling of mode information is needed to minimize alerting system errors such as unnecessary or late alerts. The benefits of the method are illustrated with two alerting scenarios where a pair of aircraft must avoid collisions when passing one another. The first scenario has a fully observable state and the second includes an uncertain mode describing whether an intruder aircraft levels off safely above the evader or is in a hazardous blunder mode. In MDP theory, outcome preferences are described in terms of utilities of different state trajectories. In keeping with this, alerting system requirements are stated in the form of a reward function. This is then used with probabilistic dynamic and sensor models to compute an alerting logic (policy) that maximizes expected utility. Performance comparisons are made between the MDP-based logics and alternate logics generated with current methods. It is found that in terms of traditional performance measures (incident rate and unnecessary alert rate), the MDP-based logic can meet or exceed that of alternate logics.

2004-08-01T00:00:00Z Clarke, John-Paul Ho, Nhut Ren, Lilling Brown, John Elmer, Kevin Tong, Kwok-On Wat, Joseph https://hdl.handle.net/1721.1/35762 2019-04-10T20:32:27Z 2004-04-01T00:00:00Z

Design and Flight Demonstration Test of a Continuous Descent Approach Procedure for Louisville International Airport Clarke, John-Paul; Ho, Nhut; Ren, Lilling; Brown, John; Elmer, Kevin; Tong, Kwok-On; Wat, Joseph A design methodology based on the principles of system analysis was used to design a noise abatement approach procedure for Louisville International Airport. In a flight demonstration test, this procedure was shown to reduce the noise at seven locations along the flight path by 3.9 to 6.5 dBA and reduce the fuel consumed during approach by 400 to 500 lbs. The noise reduction is significant given that a 3-decibel difference represents a 50% reduction in acoustic energy and is noticeable to the human ear, and the 7% reduction in the size of the 50 DNL contour that would result if all aircraft were to perform the procedure. The fuel saving is also significant given the financial benefit to airlines and the accompanying reduction in gaseous and particulate emissions. While the analysis of aircraft performance data showed how pilot delay, in combination with auto-throttle and flight management system logic, can result in deviations from the desired trajectory, the results confirm that near-term implementation of this advanced noise abatement procedure is possible. The results also provide ample motivation for proposed pilot cueing solutions and low-noise guidance features in flight management systems.

2004-04-01T00:00:00Z Major, Laura Hansman, R. John https://hdl.handle.net/1721.1/35761 2019-04-10T09:58:37Z 2004-02-01T00:00:00Z

Human-Centered Systems Analysis Of Mixed Equipage In Oceanic Air Traffic Control Major, Laura; Hansman, R. John Technical capabilities for improved communication, surveillance, and navigation (CNS) over the oceans are currently available. However, all aircraft operators will not equip simultaneously because of the high costs required. Consequently, as these CNS systems are integrated into oceanic air transportation architecture, the controller will have to manage the current low frequency surveillance and communication paths in parallel with future enhanced CNS. The cognitive effects of the mixed equipage environment were studied through field studies and experimental analysis.

2004-02-01T00:00:00Z Vigeant-Langlois, Laurence Hansman, R. John https://hdl.handle.net/1721.1/35760 2019-04-12T08:35:07Z 2004-06-01T00:00:00Z

Human-Centered Systems Analysis of Aircraft Separation from Adverse Weather Vigeant-Langlois, Laurence; Hansman, R. John Adverse weather significantly impacts the safety and efficiency of flight operations. Weather information plays a key role in mitigating the impact of adverse weather on flight operations by supporting air transportation decision-makers’ awareness of operational and mission risks. The emergence of new technologies for the surveillance, modeling, dissemination and presentation of information provides opportunities for improving both weather information and user decision-making. In order to support the development of new weather information systems, it is important to understand this complex problem thoroughly. This thesis applies a human-centered systems engineering approach to study the problem of separating aircraft from adverse weather. The approach explicitly considers the role of the human operator as part of the larger operational system. A series of models describing the interaction of the key elements of the adverse aircraft-weather encounter problem and a framework that characterizes users’ temporal decisionmaking were developed. Another framework that better matches pilots’ perspectives compared to traditional forecast verification methods articulated the value of forecast valid time according to a spacetime reference frame. The models and frameworks were validated using focused interviews with ten national subject matter experts in aviation meteorology or flight operations. The experts unanimously supported the general structure of the models and made suggestions on clarifications and refinements which were integrated in the final models. In addition, a cognitive walk-through of three adverse aircraft-weather encounters was conducted to provide an experiential perspective on the aviation weather problem. The scenarios were chosen to represent three of the most significant aviation weather hazards: icing, convective weather and low ceilings and visibility. They were built on actual meteorological information and the missions and pilot decisions were synthesized to investigate important weather encounter events. The cognitive walkthrough and the models were then used to identify opportunities for improving weather information and training. Of these, the most significant include opportunities to address users’ four-dimensional trajectorycentric perspectives and opportunities to improve the ability of pilots to make contingency plans when dealing with stochastic information.

2004-06-01T00:00:00Z Jiang, Helen Hong Hansman, R. John https://hdl.handle.net/1721.1/35759 2019-04-10T09:58:37Z 2004-12-01T00:00:00Z

An Analysis of Profit Cycles In the Airline Industry Jiang, Helen Hong; Hansman, R. John The objective of this paper is to understand the financial dynamics of the airline industry by identifying profit cycle periods of the industry and their driving factors. Assuming that the industry profit cycles could be modeled as an undamped second-order system, the fundamental cycle period was identified to be 11.3 years for the U.S. airlines and 10.5 years for the world airlines. Analyses of industry profits reveal that such cycle period is endogenous, neither deregulation nor September 11 have significantly changed it. Parametric models were developed under the hypothesis that phase lag in the system caused profit oscillations; and two hypotheses, lag in capacity response and lag in cost adjustment were studied. A parametric model was developed by hypothesizing the delay in capacity response caused profit oscillations. For this model, the system stability depends on the delay between aircraft orders and deliveries and the aggressiveness in airplane ordering. Assuming industry profits correlated to capacity shortfall, the delay and gain were calculated and the results were consistent with the observed delay between world aircraft deliveries and net profits. Since the gain in the model has lumped impacts of exogenous factors, exaggerated capacity response was observed in simulation. This indicates capacity shortfall alone cannot fully explain the industry dynamics. The model also indicates reduced delay may help to mitigate system oscillations. Similarly, a parametric model was developed by hypothesizing the delay in cost adjustment caused profit oscillations, and simulation results were consistent with industry profits. A coupled model was developed to study the joint effects of capacity and cost. Simulations indicated that the coupled model explained industry dynamics better than the individual capacity or cost models, indicating that the system behavior is driven by the joint effects of capacity response and cost adjustment. A more sophisticated model including load factor and short-term capacity effects is proposed for future work in an effort to better understand the industry dynamics. This document is based on the thesis of Helen Hong Jiang submitted to the Department

2004-12-01T00:00:00Z Anagnostakis, Ioannis Clarke, John-Paul https://hdl.handle.net/1721.1/35758 2019-04-10T09:58:37Z 2004-09-01T00:00:00Z

A Multi-Objective, Decomposition-Based Algorithm Design Methodology and its Application to Runway Operations Planning Anagnostakis, Ioannis; Clarke, John-Paul Significant delays and resulting environmental impacts are commonly observed during departure operations at major US and European airports. One approach for mitigating airport congestion and delays is to exercise tactical operations planning and control with an objective to improve the efficiency of surface and terminal area operations. As a subtask of planning airport surface operations, this thesis presents a thorough study of the structure and properties of the Runway Operations Planning (ROP) problem. Runway Operations Planning is a workload-intensive task for controllers because airport operations involve many parameters, such as departure demand level and timing that are typically characterized by a highly dynamic behavior. This research work provides insight to the nature of this task, by analyzing the different parameters involved in it and illuminating how they interact with each other and how they affect the main functions in the problem of planning operations at the runway, such as departure runway throughput and runway queuing delays. Analysis of the Runway Operations Planning problem revealed that there is a parameter of the problem, namely the demand “weight class mix”, which: a) is more “dominant” on the problem performance functions that other parameters, b) changes value much slower than other parameters and c) its value is available earlier and with more certainty than the value of other parameters. These observations enabled the parsing of the set of functions and the set of parameters in subsets, so that the problem can be addressed sequentially in more than one stage where different parameter subsets are treated in different stages. Thus, a decompositionbased algorithm design technique was introduced and applied to the design of a heuristic decomposed algorithm for solving the ROP problem. This decomposition methodology offers an original paradigm potentially applicable to the design of solution algorithms for a class of problems with functions and parameters that, similar to those of the ROP problem, can be parsed in subsets. The potential merit in decomposing the ROP problem in two stages and the resulting utility of the two-stage solution algorithm are evaluated by performing benefits analysis across specific dimensions related to airport efficiency, as well as stability and robustness analysis of the algorithm output.

2004-09-01T00:00:00Z Lohrenz, Maura C. Hansman, R. John https://hdl.handle.net/1721.1/35757 2019-04-12T08:35:07Z 2004-09-20T00:00:00Z

Investigating Issues Of Display Content Vs. Clutter During Air-To-Ground Targeting Missions Lohrenz, Maura C.; Hansman, R. John This paper investigates competing influences of display content and clutter on pilot performance during flight guidance and target acquisition phases of air-to-ground targeting missions. Based on interviews with F/A-18 pilots, a cognitive process model is presented to help understand how pilots use and transition between internal and external sources of information to support decision-making and aircraft control. Experiments were conducted in which subjects flew targeting missions using a flight simulator connected to the Navy’s FalconView moving-map. In one experiment, subjects referred to three versions of the display: 1) a detailed map overlaid with critical mission symbology, 2) the map only, and 3) mission overlays only. Flight guidance and target acquisition performances were best with the overlays-only display. Performance was comparable or worse with the combination display and significantly worse with the map only, suggesting that the distraction of map clutter countered the benefits of map content.

2004-09-20T00:00:00Z Major, Laura Johannsson, Hlynur Davison, Hayley Hvannberg, Ebba Thora Hansman, R. John https://hdl.handle.net/1721.1/35756 2019-04-12T08:35:07Z 2004-09-01T00:00:00Z

Key Human-Centered Transition Issues for Future Oceanic Air Traffic Control Systems Major, Laura; Johannsson, Hlynur; Davison, Hayley; Hvannberg, Ebba Thora; Hansman, R. John Communication, navigation, surveillance, and decision support capabilities in Oceanic air traffic control are evolving significantly. It is important to consider the effect of the changes on the controller’s task. In this paper the results from multi-disciplinary studies performed at MIT (Massachusetts Institute of Technology) and the University of Iceland are presented. At MIT, a human-centered systems analysis was used to identify key human factors issues for the future Oceanic air traffic control environment to be experimentally investigated. At the University of Iceland, a prototype for a future air traffic control display was designed and evaluated. Both studies identified three key human factors issues that require consideration. The first is a mismatch between time and space separation restrictions imposed and information support provided, requiring the controller to cognitively resolve temporal/spatial mismatches to meet restrictions. The second issue is the effects of mixed communication and surveillance equipage, which complicates the control task and requires the controller to cognitively integrate asynchronous information. The final is the importance of cultivating controller trust and understanding issues of complacency and automation disuse when implementing highly automated conflict probes that are being considered in the future Oceanic environments.

2004-09-01T00:00:00Z Hansman, R. John https://hdl.handle.net/1721.1/35726 2019-04-12T09:32:28Z 2004-04-01T00:00:00Z

Overview of Recent Trends in the Airline Industry Hansman, R. John

2004-04-01T00:00:00Z Midkif, Alan H. Hansman, R. John Reynolds, Tom G. https://hdl.handle.net/1721.1/35725 2019-04-10T09:58:34Z 2004-07-01T00:00:00Z

Air Carrier Flight Operations Midkif, Alan H.; Hansman, R. John; Reynolds, Tom G. Most air carriers operate under a system of prioritized goals including safety, customer service (on-time departures and arrivals) and operating economics. The flight operations department is responsible for the safe and efficient movement of passengers and/or cargo which ultimately generate the revenue for the airline. The major components needing to be coordinated for any given flight include the aircraft and support equipment, cockpit and cabin crews (together known as the “flight crew”), maintenance, and ground service personnel. Although the maintenance and ground crew activities are critical to support flight operations, the emphasis in this document is on the regulation and scheduling of the flight crews to conduct a given flight, followed by a detailed discussion of the activities of flight crews during the phases of a typical revenue flight sequence. Note that this chapter does not attempt to address detailed airmanship and flight maneuvering topics and only includes such information in the context of the overall flight operation. However, specific flight procedures that may have a direct impact on the operational goals are included to aid in understanding the nature and complexity of the factors involved.

2004-07-01T00:00:00Z Doble, Nathan Hansman, R. John https://hdl.handle.net/1721.1/35252 2019-04-12T07:34:05Z 2004-10-01T00:00:00Z

Experimental Evaluation Of Portable Electronic Flight Progress Strips Doble, Nathan; Hansman, R. John Air traffic service providers are increasingly embracing electronic alternatives to the traditional paper Flight Progress Strip (FPS). However, most development of such electronic systems, and of Decision Support Tools (DSTs) in general, has centered on radar-based en route or terminal-area facilities, rather than the airport air traffic control tower. Based on an analysis of the unique human factors requirements of the control tower environment, a prototype Portable Electronic FPS has been designed that also serves as an interface to a DST for departure operations. The Portable Electronic FPS has been implemented using a system of networked, handheld computers as prototype hardware. A study has been conducted to evaluate the usability of the Portable Electronic FPS. The study consisted of a human-in-the-loop experiment that simulated the tasks an air traffic controller performs at a major airport. Three issues were explored: the importance of FPS portability, the appropriateness of departure sequence DST advisories distributed onto each Portable Electronic FPS, and the advantages of interaction mechanisms enabled by an electronic interface. Test subjects used multiple versions of the Portable Electronic FPS as well as a current-day paper FPS. Quantitative measures of departure sequencing efficiency and traffic monitoring ability were recorded for each test subject, as well as subjective FPS preference rankings. This paper reviews the final design and prototype implementation of the Portable Electronic FPS, presents the design and results of the usability study, and suggests future research that should be pursued in order to create an operationally deployable Portable Electronic FPS system.

2004-10-01T00:00:00Z Jiang, Helen Hansman, R. John https://hdl.handle.net/1721.1/34988 2019-04-12T08:38:25Z 2006-09-25T00:00:00Z

An Analysis of Profit Cycles in the Airline Industry Jiang, Helen; Hansman, R. John This paper discusses the financial dynamics of the airline industry by identifying the fundamental cycle periods of profitability and their driving factors. Assuming the industry profit cycles could be modeled as an undamped second-order system, the fundamental cycle period was found to be 11.3 years for the U.S. airline industry and 10.5 years for the world airline industry. An empirical profitability model was estimated and the results revealed that such cycle period is endogenous, neither deregulation nor September 11 have significantly changed the cycle length. To analyze the causes of profit cyclicality, parametric models were developed under the hypothesis that phase lag in the system caused the profit oscillations; and two hypotheses, lag in capacity response and lag in cost adjustment were studied. Analysis of the parametric model of capacity response indicated that the system stability depends on the delay between aircraft orders and deliveries and on the aggressiveness in airplane ordering. Exaggerated capacity response was observed in the simulation as the gain in the model has lumped impacts of exogenous factors, suggesting capacity shortfall alone cannot fully explain the industry dynamics. The model also indicates reducing delay may help to mitigate system oscillations. Simulation results of the parametric model regarding cost adjustment were consistent with profit observations. Finally, a coupled model was developed to study the joint effects of capacity and cost. Simulation results indicated that the coupled model explained industry dynamics better than individual capacity or cost models, suggesting that the system behavior is driven by the joint effects of capacity response and cost adjustment.

2006-09-25T00:00:00Z Miller, Bruno Clarke, John-Paul https://hdl.handle.net/1721.1/34960 2019-04-15T00:41:55Z 2004-01-01T00:00:00Z

Investments in Rural Air Transportation Networks in Developing Countries Miller, Bruno; Clarke, John-Paul Rural airfields provide vital access to many remote regions of the world, thus enabling their socioeconomic development. While these facilities are usually very simple, their construction and maintenance can be very difficult. Thus, governments must balance the need to provide access with the cost of providing access. In this paper, we present a quantitative methodology for evaluating investment decisions in rural air transportation networks. The intended purpose of the methodology is to provide policymakers with enough understanding so that they can develop strategies that meet the accessibility needs of remote locations while making the best use of available resources. The first step in the methodology is to determine the importance of air links to the different points in the network. Next, the existing and desired infrastructure are evaluated in terms of their ability to support the expected traffic. These evaluations are followed by a gap analysis to determine the infrastructure deficit and provide the basis for the formulation of different investment strategies. In this paper we consider the case of Costa Rica and provide useful insights for policymakers interested in supporting rural air transportation networks.

2004-01-01T00:00:00Z Miller, Bruno Clarke, John-Paul https://hdl.handle.net/1721.1/34959 2019-04-10T16:54:43Z 2004-01-01T00:00:00Z

Application of Real Options to Evaluate the Development Process of New Aircraft Models Miller, Bruno; Clarke, John-Paul Investment decisions in the development and production of new aircraft models is difficult because of the technical and market uncertainties associated with such a complex process. The accompanying risks can be mitigated through a flexible approach that incorporates several decision points at different stages of the process. Therefore, as the project evolves, management will be able to diagnose its progress, compare it to previous expectations, and decide to continue or not. In this paper, we present a methodology to evaluate flexible business strategies that is based on real options analysis (ROA) and Monte Carlo simulation. This methodology takes into account the flexibility that managers have to affect the success of any given project and, therefore, it provides a better estimate of project value. Numerical results are given for a representative process based on actual aircraft manufacturer’s data.

2004-01-01T00:00:00Z Bonnefoy, Philippe Hansman, R. John https://hdl.handle.net/1721.1/34958 2019-04-11T09:50:10Z 2004-01-01T00:00:00Z

Emergence and Impact of Secondary Airports in the United States Bonnefoy, Philippe; Hansman, R. John As major airports in the United States have reached their maximum capacity and became congested, available capacity at surrounding airports has been utilized by the emergence of secondary airports. Given the expectation of a larger number of operations in the National Airspace System (NAS) in the upcoming years, this trend of secondary airports emergence is likely to strengthen. In order to understand the dynamics of the regional airport systems, a study of the factors that led to the emergence of secondary airports was performed. The distribution of population at the regional level, the existence and the proximity of a secondary basin of population close to secondary airports were identified as major factors. Ground access and airport infrastructure were also enabling factors. The nature of the regional airport system, in terms of “Hub” versus “non-Hub” was also identified as a contributing factor. The entry of a low cost carrier was determined to be the essential stimulus in the emergence phenomenon. These entries modify the airport dynamics resulting in the stimulation of both local and peripheral markets. Following the entry of a low cost carrier several other carriers, both legacy and low cost, enter and consolidate the growth of the emerging airport. As a consequence of the emergence of secondary airports and their integration into a region wide multi-airport system, they induce impacts on the NAS structure. Recent consolidations of TRACONs (Terminal Area Control) were identified as primary impacts. As there will be increasing pressure of demand on core airports in the upcoming years, the development of additional secondary airports will be required. The transition from a single core airport to region wide multi-airport systems and the emergence of new secondary airports in existing multi-airport systems, impose new constraints that need to be taken into account in the NAS improvements.

2004-01-01T00:00:00Z Mozdzanowska, Alexandra Hansman, R. John https://hdl.handle.net/1721.1/34957 2019-04-12T08:34:44Z 2004-05-01T00:00:00Z

Evaluation of Regional Jet Operating Patterns in Mozdzanowska, Alexandra; Hansman, R. John Airlines are increasingly using regional jets to better match aircraft size to high value, but limited demand markets. The increase in regional jet usage represents a significant change from traditional air traffic patterns. To investigate the possible impacts of this change on the air traffic management and control systems, this study analyzed the emerging flight patterns and performance of regional jets compared to traditional jets and turboprops. This study used ASDI data, which consists of actual flight track data, to analyze flights between January 1998 and January 2003. In addition, a study of regional jet economics, using Form 41 data, was conducted in order to better understand the observed patterns. It was found that in 1998 US regional jet patterns and utilization closely resembled those of the turboprops. Both aircraft were used for hub feeder operations. They flew relatively short distances, under 500 nautical miles, and exhibited similar cruise altitudes and speeds. These patterns began to change as the number of regional jets increased. By January 2003, the regional jets were no longer used solely for hub feeder operations, but were flying longer routes at higher altitudes and faster speeds than turboprops. As a result, regional jets have come to fill a gap in the market by flying on longer routes than the turboprops, but shorter than the narrow body jets. An economic analysis was conducted in order to better understand the observed regional jet patterns. It was found that regional jets have lower operating costs per trip and higher operating costs per ASM than traditional jets. As a result, regional jets are currently a lower cost alternative for traditional airlines because they cover the cost of regional jet flights on a per departure basis. However, if this structure were to change regional jets would become a less appealing alternative. To better understand the consequences of a change in the operation patterns, changes in the cost of regional and traditional jets were analyzed when trip length and pilot costs per block hour were normalized. It was found that regional jet costs per trip are very similar to traditional jet costs per trip when the trip length between the two aircraft categories is normalized, but that the normalization of pilot cost per block does not have a significant effect on the relative costs of the two aircraft types. In 2003, the US regional jet operations showed a high density of flights in the northeastern part of the country. This part of the US also has the largest concentration of traditional jet operations; this interaction may result in congestion problems since the two types of aircraft exhibit different performance. In particular, regional jets were observed to exhibit lower climb rates than traditional jets, which may impact air traffic control handling and sector design. It was also observed that as regional jets replace turboprops, they compete for runways and take off trajectories with narrow body jets. The combination of the different performance and the competition for resources between regional and other jets may result in increased delays and congestions as well as increased controller workload. The future growth of regional jets is uncertain. However, currently both US Airways and Jet Blue have placed orders for new Embraer aircraft indicating that the growth of regional jets will continue for the time being. In addition, both Embraer and Bombardier are currently designing and manufacturing larger regional jets. These aircraft will be designed to accommodate more passengers on further trips and as a result will further change the composition and performance capabilities of the national fleet.

2004-05-01T00:00:00Z Weibel, Roland E. Hansman, R. John https://hdl.handle.net/1721.1/34955 2019-04-14T06:53:11Z 2004-09-20T00:00:00Z

Safety Considerations for Operation of Different Classes of UAVs in the NAS Weibel, Roland E.; Hansman, R. John Recognizing the significant effort underway to integrate UAV operations in the NAS, a preliminary hazard analysis was conducted for two critical hazards of UAV operation. Models were developed to describe UAV ground impact and midair collisions. Under several assumptions, a model of ground impact was used to calculate the UAV system reliability required to meet a target level of safety, for different UAV classes differentiated by mass. The model showed a significantly higher reliability required for high-mass UAVs, and a large variation in reliability required with population density, with a two order of magnitude increase over metropolitan areas. Midair collision risk was estimated in the vicinity of airways using a model of aircraft collisions based on the density of air traffic in those regions. There is a two order of magnitude difference in risk between on-airway and on-altitude operation and operation away from airways and off major flight levels. Therefore, there are potential operating strategies that can reduce the risk of UAV operation, such as procedural separation from high population and high traffic areas. There are also additional mitigation possibilities to further reduce the risk of integrating UAVs in the NAS.

2004-09-20T00:00:00Z Carr, Francis R. https://hdl.handle.net/1721.1/34945 2019-04-15T00:41:55Z 2004-02-01T00:00:00Z

Robust Decision-Support Tools for Airport Surface Traffic Carr, Francis R. Forecasts of departure demand are one of the driving inputs to tactical decision-support tools (DSTs) for airport surface traffic. While there are well-known results on average- or worst-case forecast uncertainty, it is the forecast errors which occur under best-case minimum-uncertainty conditions which constrain robust DST design and the achievable traffic benefits. These best-case errors have never previously been characterized. Several quantitative models and techniques for computing pushback forecasts are developed. These are tested against a dataset of 17,344 real-world airline ground operations covering 3 months of Lufthansa fights transiting Frankfurt International Airport. The Lufthansa dataset includes detailed timing information on all of the turn processes, including deboarding, catering, cleaning, fueling and boarding. The dataset is carefully filtered to obtain a sample of 3820 minimum-uncertainty ground events. The forecast models and techniques are tested against this sample, and it is observed that current pushback forecast errors (on the order of §15min) cannot be reduced by a factor of more than 2 or 3. Furthermore, for each ground event, only 3 observations are necessary to achieve this best-case performance: the available ground-time between actual onblock and scheduled offblock; the time until deboarding begins; and the time until boarding ends. Any DST used in real-world operations must be robust to this “noise floor". To support the development of robust DSTs, a unified framework called ceno-scale modeling is developed. This class of models encodes a wide range of observed delay mechanisms using multi-resource synchronization (MRS) feedback networks. A ceno-scale model instance is created for Newark International Airport, and the parameter sensitivity and model fidelity are tested against a detailed real-world dataset. Based on the validated model framework, several robust dual control strategies are proposed for airport surface traffic.

2004-02-01T00:00:00Z Feron, Eric R. Hansman, R. John Odoni, Amadeo R. Cots, R.B. Delcaire, B. Hall, W.D. Idris, H.R. Muharremoglu, A. Pujet, N. https://hdl.handle.net/1721.1/34944 2019-04-15T00:40:37Z 1997-12-01T00:00:00Z

The Departure Planner: A Conceptual Discussion Feron, Eric R.; Hansman, R. John; Odoni, Amadeo R.; Cots, R.B.; Delcaire, B.; Hall, W.D.; Idris, H.R.; Muharremoglu, A.; Pujet, N.

1997-12-01T00:00:00Z Vigeant-Langlois, Laurence Hansman, R. John https://hdl.handle.net/1721.1/34942 2019-04-12T08:34:44Z 2003-01-01T00:00:00Z

Implications of Contingency Planning Support for Weather and Icing Information Vigeant-Langlois, Laurence; Hansman, R. John A human-centered systems analysis was applied to the adverse aircraft weather encounter problem in order to identify desirable functions of weather and icing information. The importance of contingency planning was identified as emerging from a system safety design methodology as well as from results of other aviation decision-making studies. The relationship between contingency planning support and information on regions clear of adverse weather was investigated in a scenariobased analysis. A rapid prototype example of the key elements in the depiction of icing conditions was developed in a case study, and the implications for the components of the icing information system were articulated.

2003-01-01T00:00:00Z Weibel, Roland E Hansman, R. John https://hdl.handle.net/1721.1/34912 2019-04-15T00:40:36Z 2006-11-21T19:12:36Z

Safety Considerations for Operation of Unmanned Aerial Vehicles in the National Airspace System Weibel, Roland E; Hansman, R. John There is currently a broad effort underway in the United States and internationally by several organizations to craft regulations enabling the safe operation of UAVs in the NAS. Current federal regulations governing unmanned aircraft are limited in scope, and the lack of regulations is a barrier to achieving the full potential benefit of UAV operations. To inform future FAA regulations, an investigation of the safety considerations for UAV operation in the NAS was performed. Key issues relevant to operations in the NAS, including performance and operating architecture were examined, as well as current rules and regulations governing unmanned aircraft. In integrating UAV operations in the NAS, it will be important to consider the implications of different levels of vehicle control and autonomous capability and the source of traffic surveillance in the system. A system safety analysis was performed according to FAA system safety guidelines for two critical hazards in UAV operation: midair collision and ground impact. Event-based models were developed describing the likelihood of ground fatalities and midair collisions under several assumptions. From the models, a risk analysis was performed calculating the expected level of safety for each hazard without mitigation. The variation of expected level of safety was determined based on vehicle characteristics and population density for the ground impact hazard, and traffic density for midair collisions. The results of the safety analysis indicate that it may be possible to operate small UAVs with few operational and size restrictions over the majority of the United States. As UAV mass increases, mitigation measures must be utilized to further reduce both ground impact and midair collision risks to target levels from FAA guidance. It is in the public interest to achieve the full benefits of UAV operations, while still preserving safety through effective mitigation of risks with the least possible restrictions. Therefore, a framework was presented under which several potential mitigation measures were introduced and could be evaluated. It is likely that UAVs will be significant users of the future NAS, and this report provides an analytical basis for evaluating future regulatory decisions.

2006-11-21T19:12:36Z Clark, John-Paul Miller, Bruno Riedel, Robin Miller, Owen Pamidimukkala, Praveen Raimondi, Michelangelo https://hdl.handle.net/1721.1/34911 2019-04-15T00:40:35Z 2006-11-21T19:09:37Z

Estimation of the Economic Benefit of Air Jamaica to Jamaica between 1995 and 2004 Clark, John-Paul; Miller, Bruno; Riedel, Robin; Miller, Owen; Pamidimukkala, Praveen; Raimondi, Michelangelo In this study, we estimate the economic benefit of Air Jamaica to Jamaica between 1995 and 2004. Specifically, we determine the economic benefit of Air Jamaica by estimating the economic contribution of air transportation for the case where Air Jamaica does not exist and then subtracting this value from the economic contribution of air transportation for the case where Air Jamaica does exist. Thus the value we determine is the incremental contribution of Air Jamaica to the Jamaican economy, i.e. the benefit that can only be attributed to the presence of Air Jamaica. Although there are many different ways in which airlines contribute to socioeconomic growth, only two of these mechanisms are explored in this study: 1) the portion of airline revenues that remain in Jamaica by virtue of the wages that are paid to residents of Jamaica, and the goods and services that are purchased from companies in Jamaica; 2) the expenditures of foreign visitors. Therefore, this study represents a conservative estimate of the benefit of Air Jamaica to the Jamaican economy. The results of our analysis indicate that the economic benefit of Air Jamaica to Jamaica between 1995 and 2004 economy was US5.491 Billion of which US$1.830 Billion was a direct incremental contribution to the economy and US$3.661 Billion is the corresponding indirect incremental contribution.

2006-11-21T19:09:37Z Forest, Laura Major Hansman, R. John https://hdl.handle.net/1721.1/34910 2019-04-11T09:50:12Z 2005-01-01T00:00:00Z

Experimental Analysis of the Integration of Mixed Surveillance Frequency into Oceanic Air Operations Forest, Laura Major; Hansman, R. John Technical capabilities for improved surveillance over the oceans are currently available through the use of satellites. However, all aircraft operators will not equip simultaneously because of the high costs required. Consequently, as these CNS systems are integrated into oceanic air transportation architecture, the controller will have to manage the current low frequency surveillance in parallel with enhanced surveillance. The cognitive effects of the mixed equipage environment were studied through experimental analysis. The results confirm that there are human performance issues with integrating mixed surveillance capabilities, which may result in safety and efficiency limitations.

2005-01-01T00:00:00Z Busing, Hans-Georg Hansman, R. John https://hdl.handle.net/1721.1/34909 2019-04-09T16:37:02Z 2006-11-21T18:53:10Z

Air Traffic Control Operating Modes and the Management of Complexity Busing, Hans-Georg; Hansman, R. John This report describes research exploring the relationship between structure and cognitive complexity in Air Traffic Control (ATC). Current work on structure and cognitive processes in ATC is reviewed leading to an ATC process model. Based on observations of the performance of the ATC system it appears that air traffic controllers have the ability to manipulate structure and structure-based abstractions in order to regulate the complexity of an ATC situation. The management of complexity has been integrated into the Controller Process Model through a Complexity Manager. It is hypothesized that the Complexity Manager operates by commanding switches between operating modes. In order to explore whether these operating modes can be observed in a simple ATC task, an experiment was designed. Participants were given scenarios with varying traffic levels. Their commands and their performance have been collected and analyzed. The experimental results show participants appeared to use each of the hypothesized operating modes. The use of the structure in each mode was also as expected.

2006-11-21T18:53:10Z Bonnefoy, Philippe A Hansman, R. John https://hdl.handle.net/1721.1/34908 2019-04-12T08:37:59Z 2006-11-21T18:48:18Z

Emergence of Secondary Airports and Dynamics of Regional Airport Systems in the United States Bonnefoy, Philippe A; Hansman, R. John With the growing demand for air transportation and limited capacity at major airports, there is a need to increase the capacity of airport systems at the metropolitan area level. The increased use of secondary airports has been and is expected to be one of the key mechanisms by which future demand is met in congested metropolitan areas. This thesis provides an analysis of the factors influencing the emergence of secondary airports and the dynamics of multi-airport systems. The congestion of the core airport, the distribution of population at the regional level, the existence and the proximity of a secondary basin of population close to secondary airports were identified as major factors. Ground access and airport infrastructure, the low level of connecting passengers at the core airport were also identified as a contributing factors. The entry of an air carrier –generally a low-cost carrier- was determined to be an essential stimulus in the emergence phenomenon impacting fares and airport competition levels resulting in market stimulation. But the emergence of secondary airports imposes new constraints that need to be taken into account in the national air transportation system improvements. By providing an identification of the factors that influence the emergence of secondary airports and an understanding of the dynamics of regional airport systems this research provides useful support for the planning and the future development of multi-airport systems.

2006-11-21T18:48:18Z Weibel, Roland E Hansman, R. John https://hdl.handle.net/1721.1/34907 2019-04-11T09:50:11Z 2005-09-26T00:00:00Z

An Integrated Approach to Evaluating Risk Mitigation Measures for UAV Operational Concepts in the NAS Weibel, Roland E; Hansman, R. John An integrated approach is outlined in this paper to evaluate risks posed by operating Unmanned Aerial Vehicles in the National Airspace System. The approach supports the systematic evaluation of potential risk mitigation measures recognizing key issues in creation of regulatory and safety policy, including public perception and UAV market forces. Risk mitigation measures are examined for two example concepts of operation: High Altitude Long Endurance UAV and small, local UAV operations. Primary hazards of ground impact and midair collision are considered. The examples illustrate three major areas of risk mitigation: exposure, recovery, and effects mitigation. The different mitigation possibilities raise key issues on how to determine appropriate UAV policies to ensure that an acceptable level of safety is achieved.

2005-09-26T00:00:00Z Davison Reynolds, Hayley J https://hdl.handle.net/1721.1/34894 2019-04-12T15:47:46Z 2006-11-20T00:00:00Z

Modeling the Air Traffic Controller's Cognitive Projection Process Davison Reynolds, Hayley J Cognitive projection enables the operator of a supervisory control system, such as air traffic control, to use predicted future behavior of the system to make decisions about if and how to control the system. New procedures and technologies being implemented in the air traffic control system innately affect the information used for projection and the type of projection required from the controller. Because cognitive projection is not well-understood, launching these projection-impacting technologies and procedures could result in the reluctance of the air traffic controllers to accept these advancements or limit the system performance. A Projection Process Model and a Projection Error Concept were proposed to describe the controller’s projection process and the contextual system influences on the projection process. The two primary influences on the projection process were the information/display system and task-based projection requirements. A mismatch between the information/display system states and the task-based projection requirements was described through a cognitive transform concept. The projection process itself is composed of the state mental model and the time into the future over which the projection is made. Hypotheses based on the assumptions of the Projection Process Model and Projection Error Concept were probed through an experiment using an ATC task paradigm. Results were consistent with the proposed models. They suggested that the controllers were able to incorporate higher-level dynamics into the state mental models used for projection and that the quality of the state mental model used was marginally influenced by the error tolerance required in the task. The application of the Projection Process Model and Projection Error Concept was then illustrated through the analysis of the impact on projection from two ATC domain examples of technology and procedure implementation. The Constant Descent Approach Procedure in the TRACON impacted the intent, projection timespan, and abstractions used in the mental model of the controllers. The Oceanic ATC surveillance, communication and workstation improvements resulted in an impact on the states to be projected, intent, projection timespan, and human/automation projection responsibility. Suggestions for improved transition for the projection process were then provided based on the analysis.

2006-11-20T00:00:00Z Bonnefoy, Philippe A Hansman, R. John https://hdl.handle.net/1721.1/34895 2019-04-15T00:40:35Z 2006-11-20T01:02:41Z

Investigation of the Potential Impacts of the Entry of Very Light Jets in the National Airspace System Bonnefoy, Philippe A; Hansman, R. John Very Light Jets (VLJs) constitute a class of three to eight passenger turbofan-powered aircraft that will enter service in 2006 and will need to be integrated into the National Airspace System. An aircraft performance analysis showed similarities between the predicted performance and capability of Very Light Jets and the performance of existing Light Jets. Based on this an analysis of operating patterns of existing Light Jets was used to predict how Very Light Jets will be operated. Using 396 days of traffic data from the FAA Enhanced Traffic Management System (ETMS), the operating patterns of existing Light Jets were analyzed. It was found that 64% of all the flights flown by Light Jets had their origin, destination or both within the top 23 regional airport systems in the continental United States. This concentration of LJ traffic was found in areas of the air transportation system that are currently exhibiting dense traffic and capacity constraints. The structure of the network of routes flown by existing Light Jets was also studied and a model of network growth was developed. It is anticipated that this concentration will persist with emerging Very Light Jet traffic. This concentration of traffic at key areas in the system will have implications for air traffic control management and airport activity. For regional airport systems, core airports are expected to saturate and, reliever airports will become critical for accommodating traffic demand. The entry of Very Light Jets will significantly increase the traffic load at the terminal airspace; Terminal Radar Approach Control (TRACON). These impacts need to be taken into account to allow a successful integration of these aircraft in the National Airspace System.

2006-11-20T01:02:41Z