10th Seminar Papers

All papers and presentations can be downloaded and distributed free of charge. Please use the following publication reference: FAA/EUROCONTROL (Editors): Proceedings of the USA/FAA Air Traffic Management R&D Seminar 2013. ISSN 2406-4068.

Paper ID Title Paper Presentation Theme
1 163 Airport Gate Scheduling for Passengers, Aircraft, and Operation
Author: Sang Hyun Kim , Eric Feron, Aude Marzuoli, John-Paul Clarke, Daniel Delahaye

abstract

Passengers' experience is becoming a key metric to evaluate the air transportation system's performance. Efficient and robust tools to handle airport operations are needed along with a better understanding of passengers' interests and concerns. Among various airport operations, this paper studies airport gate scheduling for improved passengers' experience. Three objectives accounting for passengers, aircraft, and operation are presented. Trade-offs between these objectives are analyzed, and a balancing objective function is proposed. The results show that the balanced objective can improve the efficiency of traffic flow in passenger terminals and on ramps, as well as the robustness of gate operations.
pdf logo image pdf logo image ATM Performance Measurement and Management
2 169 Evaluation of the Controller-Managed Spacing Tools, Flight-deck Interval Management and Terminal Area Metering Capabilities for the ATM Technology Demonstration #1
Author: Jane Thipphavong , Harry Swenson, Jaewoo Jung, Kevin Witzberger, Melody Lin, Jimmy Nguyen, Lynne Martin, Michael Downs, Terry Smith

abstract

NASA has developed a suite of advanced arrival management technologies combining time-based scheduling with controller- and flight deck-based precision spacing capabilities that allow fuel-efficient arrival operations during periods of high throughput. An operational demonstration of these integrated technologies, i.e., the ATM Technology Demonstration #1 (ATD-1), is slated for 2016. Human-in-the-loop simulations were conducted to evaluate the performance of the ATD-1 system and validate operational feasibility. The ATD-1 system was found to be robust to scenarios with saturated demand levels and high levels of system delay. High throughput, 10% above baseline demand levels, and schedule conformance less than 20 seconds at the 75th percentile were achievable. The flight-deck interval management capabilities also improved the median schedule conformance at the final approach fix from 5 to 3 seconds and with less variance.
pdf logo image pdf logo image Air Ground Integrated Concepts
3 170 Assessing the Benefits of NextGen Performance Based Navigation (PBN)
Author: Sebastian Timar , George Hunter, Joseph Post

abstract

NextGen is the ongoing transformation of air traffic control technologies and procedures in the United States. Two key components of NextGen are Performance Based Navigation (PBN) and the Optimization of Airspace and Procedures in the Metroplex (OAPM). PBN leverages state-of-the-art navigation technologies, such as satellite-based Area Navigation (RNAV) and Required Navigation Performance (RNP), to improve airport access, shorten flight paths, and increase en route efficiency. OAPM is a systematic and expedited approach to implementing PBN procedures and airspace changes. The Federal Aviation Administration (FAA) is seeking to quantify the benefits of Performance Based Navigation (PBN). The approach is to identify all PBN benefit mechanisms, develop explicit models capturing those mechanisms, and conduct simulations to quantify their impacts under representative operating conditions. In support of this effort, we investigated the throughput impact of implementing PBN to mitigate metroplex inefficiencies. Metroplex inefficiencies identified in this study involved individual or multiple airports, typically occurred in the terminal airspace domain, and impacted both departures and arrivals. PBN capabilities included RNAV Standard Instrument Departure (SID) and Standard Terminal Arrival (STAR) procedures, and RNP Approval Required (AR) final approach procedures. The investigation included simulations to evaluate the throughput impacts of RNAV SIDs or STARs in addressing metroplex inefficiencies. We formulated simple, generic queuing system-based models of the baseline SIDs or STARs capturing the inefficiency, and the RNAV SIDs or STARs mitigating the inefficiency. We then extended the models to represent instances in the Northern California metroplex. Results show that RNAV SIDs and STARs demonstrated significant increases in throughput compared with baseline SIDs and STARs, particularly at saturated traffic demand levels. This paper describes the modeling assumptions, methods, and results including the quantitative throughput impacts and their sensitivity to traffic level, traffic distribution, and the in-trail separation minima.
pdf logo image pdf logo image Enhanced Surveillance and Navigation
4 177 An Operational Evaluation of the Ground Delay Program Parameters Selection Model (GPSM)
Author: Lara Shisler , Christopher Provan, David Clark, William Chan, Shon Grabbe, Kenneth Venzke, Christine Riley, Dan Gilani, Ed Corcoran

abstract

The results of an operational evaluation of an Air Traffic Management (ATM)-Weather integrated tool, the Ground Delay Program (GDP) Parameters Selection Model (GPSM), are presented. A shadow evaluation was conducted in 2011, followed by an operational evaluation in 2012. The execution of these evaluations required collaboration and joint support across various agencies and organizations, including the National Aeronautics and Space Administration (NASA), the Federal Aviation Administration (FAA), the National Weather Service (NWS), Mosaic ATM, and MIT Lincoln Laboratory, along with the participation of the National Airspace System (NAS) user community. The shadow evaluation in 2011 showed that ground delays issued during the initial GDP could have been reduced by 20% if GPSM’s recommendations had been used operationally. These promising results led to an operational evaluation the following year. Despite challenges related to unexpected weather patterns, weather sensor outages, and slow user acceptance, analytical results show that GPSM provided benefits when used in operational decision making. On days where GPSM recommendations were closely followed, ground delays were on average 20% lower relative to days where recommendations were not followed, consistent with expectations set in 2011. The gap between planned and observed arrival rates fell by 29% relative to the preceding three years.
pdf logo image pdf logo image Weather in ATM
5 180 Investigation of NASA’s Spot and Runway Departure Advisor Concept at PHL, CLT, and LAX Airports
Author: Stephen Atkins , Brian Capozzi, Andrew Churchill, Alicia Fernandes, Christopher Provan

abstract

NASA has developed the Spot and Runway Departure Advisor (SARDA), which plans spot crossing times and runway sequences to more efficiently manage departures on an airport surface, and extensively studied the concept and algorithms in the context of Dallas/Fort Worth International Airport. This paper reports on a study of the SARDA concept at three new airports – Philadelphia International Airport (PHL), Charlotte-Douglas International Airport (CLT), and Los Angeles International Airport (LAX). The investigation of SARDA at these new airports included both fast-time simulation experiments as well as a human factors evaluation. A fast-time simulation was developed for PHL, CLT, and LAX airports, capable of simulating both baseline operations and operations with NASA’s SARDA concept in use. Multiple traffic scenarios were simulated at each airport and metrics detailing the differences between the SARDA and baseline operations analyzed. Results supported the conclusion that SARDA provides substantial benefits at all three airports. To complement the simulations, structured interviews were conducted with retired air traffic controllers who had experience at the focus airports. The human factors study provided a qualitative, alternative investigation into how SARDA would operate at these airports, and identified issues not observable through the simulations as well as additional concept and algorithmic requirements related to off-nominal situations.
pdf logo image pdf logo image Trajectory and Queue Management
6 182 2011 Trajectory Based Operations Flight Trials
Author: Christopher Wynnyk , Paul MacWilliams, Mahesh Balakrishna, Thomas Becher

abstract

This paper presents findings from the Federal Aviation Administration (FAA) 2011 Trajectory Based Operations (TBO) flight trials, performed November 30, 2011 to December 22, 2011 at Seattle-Tacoma International Airport (KSEA). The flight trials evaluated the operational concept of meeting metering times into the terminal area using the Required Time-of-Arrival (RTA) function available in modern Flight Management Systems (FMSs). The trial objectives were to test the concept on a large scale, streamline the process of assigning an RTA, and facilitate an in-depth evaluation of the utility of RTA as a flow management tool for Air Traffic Control (ATC) and operators. Findings show that the Boeing 737 Next Generation (B737NG) aircraft equipped with GE Aviation FMSs are capable of meeting the technical performance expectations of RTA. A total of 833 Alaska Airline (ASA) revenue flights participated in the trials, with 595 aircraft (71%) executing an RTA to completion, and 575 of those 595 (96.6%) arriving within a 30 second tolerance. The trials identify several areas where additional research, standardization, and automation enhancements are needed for RTA to be operationally viable.
pdf logo image pdf logo image Trajectory and Queue Management
7 183 Identifying Temporally Persistent Flows in the Terminal Airspace via Spectral Clustering
Author: Marco Enriquez  

abstract

Given a specified amount of flight trajectory data, data reduction and clustering methods (e.g., Principal Components Analysis and k-means) have become established tools for identifying flows (i.e., a group of similar flight trajectories). However, most flow identification algorithms in the literature rely solely on spatial clustering, without considering the temporal dimension. Temporal characterization of flows is important, as it: enables identification of salient air traffic features, provides a basis for scenario (“what-if”) analyses, and allows for a more robust distillation of large and time-varying air traffic datasets. To address this shortcoming, this work proposes a methodology for identifying flows which persist over an arbitrary time span. This process leverages a generic Spectral Clustering framework, building upon the methodologies established by Enriquez and Kurcz [4]. This algorithmic approach produces robust results, while remaining easy to implement and being computationally inexpensive. We present two examples to show the promise of this algorithm. First, the algorithm is used to automatically identify days in which irregular air traffic patterns occur in the Miami International Airport (MIA) terminal airspace. Second, we use this algorithm to help identify the minimum required number of new Performance Based Navigation (PBN) arrival and departure procedures in the National Airspace (NAS), based on six months of historic data.
pdf logo image pdf logo image ATM Performance Measurement and Management
8 184 ADS-B: The Case for London Terminal Maneuvering Area (LTMA)
Author: Busyairah Ali , Arnab Majumdar, Washington Ochieng, Wolfgang Schuster

abstract

EUROCONTROL in collaboration with various Air Navigation Service Providers (ANSPs) in Europe and in the United Kingdom established the CASCADE program to coordinate the implementation of Automatic Dependent Surveillance Broadcast (ADS-B) applications. In this program, the CRISTAL initiative provides data from validation trials in each country, to test the ADS-B technology in real scenarios where the operational needs exist. The ADS-B system is expected to play a key role to facilitate some of the safety-critical functions envisioned under the future operational concepts, including self-separation and Air Traffic Control based separation with reduced separation minima. ADS-B is a very complex system, highly dependent on the navigation and communication systems. A rigorous, clear and comprehensive assessment method is required to ensure that it is safe to operate in any particular context. This paper proposes a comprehensive framework to evaluate ADS-B data (obtained from NATS CRISTAL project) performance to assess whether it can meet the accuracy, latency and update rate requirements to support the above-mentioned safety-critical applications. In the proposed framework, Global Positioning System (GPS) data from aircraft navigation system are used as the reference data to validate ADS-B data accuracy as recorded by ground stations. The framework begins by decoding both sets of data (ADS-B and GPS) into the ASCII format. Both sets are then correlated based on the time and horizontal position, the most challenging task in the data evaluation process. A statistical evaluation is carried out in terms of accuracy, latency and update rate. The key challenges in this analysis and errors identified in each dataset are discussed in this paper.
pdf logo image pdf logo image Enhanced Surveillance and Navigation
9 189 Operational Demonstration of a Performance-Based Separation Standard at The Hartsfield-Jackson Atlanta International Airport - Implementation and Benefits of Equivalent Lateral Spacing Operation (ELSO) Departures
Author: Ralf Mayer , Dennis J. Zondervan, Remi L. Gottheil, Graham K. Glover

abstract

Performance-Based Navigation (PBN) represents a cornerstone of the Federal Aviation Administration (FAA) Next Generation Air Transportation System (NextGen). Improvements in aircraft navigation precision associated with PBN operations enable the development of advanced spacing concepts that evolve currently applicable separation standards. The Equivalent Lateral Spacing Operation (ELSO) concept was developed to advance the current 15-degree divergence requirement for independent parallel as well as successive departures and enables reduced-divergence departure operations. The concept was first presented at the Ninth ATM Seminar in 2011. The Hartsfield-Jackson Atlanta International Airport (KATL) implemented reduced-divergence Area Navigation (RNAV) departure procedures based on this concept on 20 October 2011. This paper outlines the standard concept and reviews KATL’s designs of RNAV ELSO procedures. It also describes the implementation approach taken to demonstrate the standard concept and presents the methodologies developed to characterize associated operational changes and estimate resulting benefits. For the 2011 level of departure demand, the results indicate a net average operator benefit of $44.00 per KATL departure and a net annual operator benefit of $19.2 million at the airport. Successful operational demonstration of the ELSO concept at KATL paves the way for regulatory changes that adopt the concept as a separation standard.
pdf logo image pdf logo image Enhanced Surveillance and Navigation
10 192 Increased Acceptance of Controller Assistance by Automatic Speech Recognition
Author: Hartmut Helmke , Heiko Ehr, Matthias Kleinert, Friedrich Faubel, Dietrich Klakow

abstract

Situation awareness of today's automation relies on sensor information, data bases and the information delivered by the operator using an appropriate HMI. The situation is mostly influenced by voice communications between controller and pilots. Hence, voice communication is an important part for the human operator to implement his plans. Voice communication runs independent and in parallel to the process the automation performs to understand the situation. Therefore, the automation, specifically the support system, is not aware of agreements between human operators. Even worse, the operators have additional effort to inform the support systems about their communication, i.e. their intents. This additional effort can be avoided by using automatic speech recognition systems (ASR). Nowadays, ASR is used in many applications, e.g. Siri® in Apple's iPhone®. This paper focuses on the integration of ASR with DLR's arrival manager 4D-CARMA. ASR improves situation awareness of both assistant system and controller. As the controller is responsible for his advisories he sometimes deviates from the recommendations of the automation. The automation often needs at least 40 seconds until it recognizes the deviations from the plan if radar data is available only. Trials performed at DLR's Institute of Flight Guidance have shown that ASR can reduce this deviation time of an Arrival Manager (AMAN) by approx. 90% down to 5 seconds.j As a side-effect, the combination of ASR and AMAN also improves the performance of ASR. The AMAN provides context information about the current and estimated future situations. It creates hypotheses on controller intents and predicts which advisories the controller will probably transmit via voice. First trials have shown that this approach can reduce the word error rate by up to 80%. This can foster the use of ASR in ATM.
pdf logo image pdf logo image Human Factors
11 193 Which data provide the best insight? A field trial for validating a remote tower operation concept.
Author: Maik Friedrich , Christoph Möhlenbrink

abstract

This paper describes the validation of a Remote Tower Control workplace. The study shows how Air Traffic Control Officers (ATCOs) observe traffic from a Tower Control Working Position at Airport Erfurt-Weimar (ERF) in comparison to a Remote Controller Working Position. The validation exercise targets low traffic density airports. Shadow-mode trials were used to cover perceptual, operational and human factors aspects of a Remote Tower System, including a live video panorama and a German Aerospace Center (DLR) research aircraft. The aircraft was used to fly different maneuvers within the aerodrome. These maneuvers allow insights on the detectability of an aircraft within different distances from the tower and the gathering of operation information about an aircraft status. In addition, a Deutsche Flugsicherung (DFS) vehicle was used to position static objects on the airfield to determine the detectability of these objects for different distances to the Control Tower (RTO-camera system). Eight ATCOs from the DFS participated in the validation exercise. Time-synchronized questionnaires for the controller working position remote (CWP-remote) and the controller working position tower (CWP-tower) were applied, addressing operational relevant questions to the ATCOs. The results reveal that the information sources play a different role at the CWP-remote than for the CWP-tower. The results are discussed taking performance and subjective data into consideration. Further, the implications for the consolidation of functional requirements and system specifications for a future remote tower system are worked out.
pdf logo image pdf logo image Human Factors
12 198 Ground-based Estimation of the Aircraft Mass, Adaptive vs. Least Squares Method
Author: Richard Alligier , David Gianazza, Nicolas Durand

abstract

This paper focuses on the estimation of the aircraft mass in ground-based applications. Mass is a key parameter for climb prediction. It is currently not available to ground- based trajectory predictors because it is considered a competitive parameter by many airlines. There is hope that the aircraft mass might become widely available someday, but in the meantime it is possible to estimate an equivalent mass from the data already available, assuming the thrust to be known (maximum climb thrust for example). In this paper, we compare the performances of two mass esti- mation methods proposed in recent publications. Both methods estimate the aircraft mass by fitting the modeled energy rate (i.e. the power of the forces acting on the aircraft) with the energy rate observed at several points of the past trajectory. The first method, proposed by Schultz et al., dynamically adjusts the weight parameter so as to fit the energy rate, using an adaptive sensitivity parameter to weight each observation. The second method, introduced in one of our previous publications, estimates the mass by minimizing the quadratic error on the observed energy rate, taking advantage of the polynomial expression of the modeled power when using the BADA model. The robustness of both methods to the observation errors is assessed, using simulated data with various distributions of the noise added to the observed state variables. The results show that both methods are able to find mass estimates that are very close to the “actual” mass, with slightly better performances for the least squares method.
pdf logo image pdf logo image Trajectory and Queue Management
13 199 Applying Flight-deck Interval Management based Continuous Descent Operation for Arrival Air Traffic to Tokyo International Airport
Author: Eri Itoh , Kazuhiko Uejima

abstract

Aiming to realize Continuous Descent Operation (CDO) in high-density air traffic, Flight-deck Interval Management (FIM) is seen as one of the promising applications in the Aircraft Surveillance Applications System (ASAS). In the FIM application, an aircraft’s arrival time at an airport is estimated while it is in flight, and its airspeed is controlled to achieve an assigned time spacing between its immediately preceding aircraft at the runway threshold. In order to evaluate the performance of the FIM application, this paper simulates CDO based on the FIM application for arrivals at Tokyo International Airport. A medium-fidelity aircraft model, which includes Vertical/Lateral NaVigation (VNAV/LNAV) autopilot modes, an engine system, and a Total Energy Control System (TECS), is implemented in a fast-time simulation. Potential CDO arrival routes at Tokyo International Airport are proposed. The simulation results evaluate the accuracy of FIM-based time spacing and fuel consumption.
pdf logo image pdf logo image Separation
14 205 Benefits Analysis of a Departure Management Prototype for the New York Area
Author: James DeArmon , Norma Taber, Hilton Bateman, Lixia Song, Tudor Masek, Daniel Gilani

abstract

Integrated Departure Route Planning (IDRP) is a decision support tool being developed and prototyped by MITRE's Center for Advance Aviation System Development (CAASD) to explore new concepts and capabilities for departure management. IDRP provides demand estimates for departure fixes and routes in terminal airspace, including identification of specific flights impacted by capacity constraints, their route information, and accurate estimates of their expected take-off times. In general, IDRP benefits accrue when there is contention for departure resources (runways, fixes, routes, sectors), plus the feasibility of off-loading or otherwise balancing demand as a means of mitigating delay. This scenario is common in the New York area, where the prototype has been installed since 2009. In 2011 and 2012, field evaluations were conducted at tower, terminal, and center facilities. These evaluations allowed the capture of “use cases”—instances of essential applications of the tool. These use cases were later examined via offline replay, and led to benefits analyses in which a queuing model was employed to compare scenarios with and without IDRP. The modeling suggests significant benefits are attributable to IDRP.
pdf logo image pdf logo image ATM Performance Measurement and Management
15 208 An Investigation of Flight Deck Data Link in the Terminal Area
Author: Sandra Lozito , Lynne Martin, John Kaneshige, Victoria Dulchinos, Shivanjli Sharma

abstract

Abstract— The Next Generation Air Transportation System (NextGen) and Europe’s Single European Sky ATM Research (SESAR) concepts require an increased use of trajectory-based operations, including extensive strategic air traffic control clearances. The clearances can be lengthy and complex, which necessitates data link communications to allow for message permanence and integration into the autoflight systems (i.e., “autoload” capability). This paper examines the use of flight deck data link communications for strategic and tactical clearance usage in the terminal area. A human-in-the-loop simulation was conducted using a high-fidelity flight deck simulator, with ten commercial flight crews as participants. Data were collected from six flight scenarios in the San Francisco terminal airspace. The variables of interest were ATC message modality (voice v. data link), temporal aspect of the message (tactical v. strategic) and message length. Dependent variables were message response times, communication clarifications, communication-related errors, and pilot workload. Response time results were longer in data link compared to voice, a finding that has been consistently revealed in a number of other simulations [1]. In addition, strategic clearances and longer messages resulted in a greater number of clarifications and errors, suggesting an increase in uncertainty of message interpretation for the flight crews when compared to tactical clearances. The implications for strategic and compound clearance usage in NextGen and SESAR are discussed.
pdf logo image pdf logo image Human Factors
16 211 Comparison of operational wind forecasts with recorded flight data
Author: Emilien Robert , David De Smedt

abstract

The behavior of an aircraft adjusting its speed in order to meet a Required Time of Arrival at a given fix in its flight plan strongly depends on the accuracy of the predicted time of arrival at that fix. Thus, assessing the accuracy of such predictions is a key element in the research on time based operations in Air Traffic Management. The accuracy of a predicted Time of Arrival at a given fix will depend on the weather forecast that is available in the cockpit. For thousands of flights over a one year period, the forecasted winds that were uplinked from the ground to the aircraft have been compared with the winds measured by the aircraft. Given the large number of flights, a statistical approach was possible and the distributions (standard deviations and mean values) of the wind speed difference, wind direction difference and resulting groundspeed difference were computed. Additionally, results have been analyzed from two different perspectives. First, a waypoint-based analysis has been performed for which the statistics have been computed for all the waypoints of all the flights. The impact of different elements, e.g. flight of phase, wind magnitude, waypoint altitude, season, aircraft tail number and forecast latency has been assessed. It seems that the wind magnitude and the forecast latency are the main drivers. Secondly, a trajectory-based analysis has been performed for which the data along a complete descent profile has been averaged for each flight, to obtain an idea of the impact of the wind forecasts on the average ground speed uncertainty during descent. This analysis has shown that the difference in average ground speed during descent that would result from applying the measured winds instead of the forecasted winds in the trajectory computations, is below 12 knots for 95% of the time.
pdf logo image pdf logo image Weather in ATM
17 212 Energy Efficient Strategies for Reducing the Environmental Impact of Aviation
Author: Banavar Sridhar , Neil Chen, Hok Ng

abstract

The main goal of Air Traffic Management (ATM) is to enable safe operation of air traffic while accommodating the demand and doing it efficiently with minimum disruption to schedules. The impact of aircraft emissions on the environment adds an additional dimension to the planning of aircraft operations. This paper describes a new simulation capability to analyze the relationship between air traffic operations and their impact on the environment. This is the first simulation to integrate all air traffic in the US based on flight plans, aircraft trajectory calculations based on predicted wind data, contrail calculations based on predicted temperature and humidity data, a common metric to combine the effects of different types of emissions, and algorithms to generate alternate trajectories for aircraft traveling between city-pairs. The integrated simulation is used to evaluate the energy efficiency of contrail reduction strategies. The aircraft trajectories are varied from their baseline flight plans to reduce contrails in three different ways: changes to altitude, optimal changes to planned route, and three-dimensional change of trajectory. The method is applied to three different scenarios: a single flight between a city-pair, all flights between 12 city-pairs, and all flights in the US airspace. Results for the 12 city-pairs show that contrail reduction involving horizontal route change only is not fuel efficient, the three-dimensional trajectory change produces the best results at a computational cost, and changes to the altitude only produces good results as well as the ability to add airspace capacity constraints. For the scenario of all flights in the US airspace, initial results based on one month data show that contrail reduction strategies involving altitude changes applied to medium and long-range flights on days with high-contrail activity provide the maximum environmental benefit for a small reduction in energy efficiency.
pdf logo image pdf logo image Environment and Energy Efficiency
18 215 Human Factors Evaluation of Conflict Detection Tool for Terminal Area
Author: Savita Verma , Huabin Tang, Debbi Ballinger, Thomas Kozon, Amir Farrahi, Fay Chinn, Estela Buchmann, John Walker, Darrell Wooten, Jacob Pfeiffer, Diane Carpenter, Ronald Lehmer

abstract

A conflict detection and resolution tool¬, Terminal-area Tactical Separation-Assured Flight Environment (T-TSAFE), is being developed to improve the timeliness and accuracy of alerts and reduce the false alert rate observed with the currently deployed technology. The legacy system in use today, Conflict Alert, relies primarily on a dead reckoning algorithm, whereas T-TSAFE uses intent information to augment dead reckoning. In previous experiments, T-TSAFE was found to reduce the rate of false alerts and increase time between the alert to the controller and a loss of separation over the legacy system. In the present study, T-TSAFE was tested under two meteorological conditions, 1) all aircraft operated under instrument flight regimen, and 2) some aircraft operated under mixed operating conditions. The tool was used to visually alert controllers to predicted Losses of separation throughout the terminal airspace, and show compression errors, on final approach. The performance of T-TSAFE on final approach was compared with Automated Terminal Proximity Alert (ATPA), a tool recently deployed by the FAA. Results show that controllers did not report differences in workload or situational awareness between the T-TSAFE and ATPA cones but did prefer T-TSAFE features over ATPA functionality. T-TSAFE will provide one tool that shows alerts in the data blocks and compression errors via cones on the final approach, implementing all tactical conflict detection and alerting via one tool in TRACON airspace.
pdf logo image pdf logo image Human Factors
19 216 Airspace Sectorisation using Constraint-Based Local Search
Author: Pierre Flener , Peter Jägare, Justin Pearson

abstract

Airspace sectorisation provides a partition of a given airspace into sectors, subject to geometric constraints and workload constraints, so that some cost is minimised. Using the constraint programming paradigm, we define plug-and-play airspace sectorisation constraints and use them to model declaratively a problem of free-form static airspace sectorisation starting from a regular mesh of cells. We design a local search (meta-) heuristic that operates on the model and is competitive with the existing NEVAC Sector Builder Algorithm.
pdf logo image pdf logo image Network and Strategic Traffic Flow Optimization
20 217 Improved Trajectory Information for the Future Flight Planning Environment
Author: Stephane Mondoloni  

abstract

The impact on ATM performance of improved trajectory-related information exchange was determined. This was first evaluated on trajectory prediction accuracy with a follow-on impact on conflict detection and resolution and flow management performance. The trajectory prediction model was validated against operational data to ensure validity of the impact of variability in parameters. The distinction between pre- and post-clearance trajectories enabled an assessment of the impact of open versus closes clearances. Uncertainty was shown to be reducible to one-third of present levels with closed clearances and improved data exchange. Normalized conflict detection performance was sensitive to the transitioning state of flights, significantly more than to airspace. Resulting improvements in resolution were shown to reduce conflict-induced perturbations by up to 3.5 nautical miles per flight hour. The combined reduction in uncertainty and conflict-induced perturbations were evaluated against alternative TFM strategies. An example illustrated reductions in fuel of 60 pounds per flight, 2.2 minutes of ground delay and 50 seconds of airborne delay per flight.
pdf logo image pdf logo image Trajectory and Queue Management
21 220 Performance Evaluation of Individual Aircraft Based Advisory Concept for Surface Management
Author: Gautam Gupta , Waqar Malik, Leonard Tobias, Yoon Jung, Ty Hoang, Miwa Hayashi

abstract

Surface operations at airports in the US are based on tactical operations, where departure aircraft primarily queue up and wait at the departure runways. NASA’s Spot And Runway Departure Advisor (SARDA) tool was developed to address these inefficiencies through Air Traffic Control Tower advisories. The SARDA system is being updated to include collaborative gate hold, either tactically or strategically. This paper presents the results of the human-in-the-loop evaluation of the tactical gate hold version of SARDA in a 360? simulated tower setting. The simulations were conducted for the east side of the Dallas/Fort Worth airport. The new system provides gate hold, Ground Controller and Local Controller advisories based on a single scheduler. Simulations were conducted with SARDA on and off, the off case reflecting current day operations with no gate hold. Scenarios based on medium (1.2x current levels) and heavy (1.5x current levels) traffic were explored. Data collected from the simulation were analyzed for runway usage, delay for departures and arrivals, and fuel consumption. Further, Traffic Management Initiatives were introduced for a subset of the aircraft. Results indicated that runway usage did not change with the use of SARDA, i.e., there was no loss in runway throughput as compared to baseline. Taxiing delay was significantly reduced with the use of advisory by 45% in medium scenarios and 60% in heavy. Observed gate-holds were less than 15 minutes in all but one scenario, and even in this scenario 95% of the aircraft had a gate hold of less than 15 minutes. Arrival delay was unaffected by the use of advisory. Total fuel consumption was also reduced by 23% in medium traffic and 33% in heavy. TMI compliance appeared unaffected by the advisory.
pdf logo image pdf logo image Integrated Airport/Airside Operations
22 222 Validation of the Time Based Separations concept at London Heathrow Airport
Author: Peter Choroba , Charles Morris, John Peters

abstract

Headwind conditions on final approach cause a reduction in the landing rate which impacts not only the achieved capacity, but also the predictability of operations, time and fuel efficiency, and the environment (emissions). The ground speed reduction in headwind conditions results in an increase in the time spacing between each arrival pair for distance-based separations. The Time Based Separation (TBS) concept changes the separation rules on final approach from distance based to time based to stabilize the time spacing between arrival pairs across headwind conditions in order to recover the lost landing rate currently experienced. This paper presents the key results of the final research phase of the validation of the TBS concept. This validation has been conducted in the framework of the SESAR Development phase project P06.08.01 Flexible and Dynamic Use of Wake Turbulence Separations. The work in P06.08.01 started in 2010 and is about to be finalized in February 2013 achieving pre-industrial development (V3) maturity level. The project has developed and assessed both the generic TBS concept and a local adaptation of the concept to the London Heathrow operating environment. The scope of this paper is focused on the validation of the concept for London Heathrow (LHR) airport covering the real-time simulation results and the wake turbulence safety data analysis results.
pdf logo image pdf logo image Separation
23 223 Flexibility Metrics and Their Application to Departure Queue Management
Author: Len Wojcik , Stephane Mondoloni, Seli Agbolosu-Amison, Paul Wang

abstract

Flexibility for operators is a Key Performance Area (KPA) for Air Traffic Management (ATM). This paper presents a framework for development of operator flexibility metrics, with a first test-case application to management of departure queues. Through the use of virtual queuing (VQ) in departure operations, operators are provided with additional flexibility in prioritizing flights for departure. VQ allows flights whose delays are more expensive to skip ahead in the departure queue, while other flights with less expensive delays move back. Operators are expected to benefit significantly from the additional flexibility of VQ because the cost of departure queuing delays can vary widely among different flights due to differences in delay already accumulated, different number and types of passengers, and considerations such as crew time limits. Flexibility metrics derived from delay recovered with VQ relative to physical queuing (PQ) are compared under a variety of operational scenarios. These scenarios include: non-linear delay costs, variable costs by aircraft type, flexibility across all flights and flexibility constrained to intra-operator exchanges, as well as small physical queues at the departure runway end. Flexibility measures have been defined that are not dependent on the specifics of the operator business case (i.e., cost structure or decision criteria). This is accomplished through a comparative assessment of flexibility metrics derived from fast-time simulations assuming a variety of operator cost functions and optimization objectives. Results show that metrics can be normalized to allow operators, based upon their cost-structure and optimization objectives, to infer a value of improved flexibility. Results also indicate that constraining exchanges to intra-operator and including small physical queues at the departure runway end substantially reduce the flexibility performance of VQ, which implies that operational mechanisms to permit inter-operator exchanges and to reduce the size of small physical queues
pdf logo image pdf logo image ATM Performance Measurement and Management
24 226 Assessing the NextGen Avionics Business Case from the Airline Perspective: The Implications of Airline Responses to Changes in Operational Performance
Author: Felipe Moreno-Hines , Deborah Kirkman

abstract

The Next Generation Air Transportation System (NextGen) is expected to improve flight efficiency in the National Airspace System (NAS). However, some of these benefits will only be realized at the pace with which operators equip their fleets with the required enabling avionics. To accurately assess the prospects of voluntary equipage, policymakers must understand the value of NextGen improvements as seen from the airlines’ perspective. Traditional cost-benefit valuation methods are not well suited for providing this perspective. The MITRE Corporation (MITRE) conducted research to better understand how airlines perceive NextGen, and how they internalize changes in flight performance in their operations. This understanding was pursued through interviews with airline managers and with regression analysis of historical airline operational data. We observe the pervasiveness of block time management in response to operational changes for a subset of airlines, and the impact of this response on various aspects of airline operations. The results of this research will be used to incorporate airline response into operational modeling and benefit valuation methodologies.
pdf logo image pdf logo image Finance and Policy
25 229 Sector Workload Model for Benefits Analysis and Convective Weather Capacity Prediction
Author: Jerry Welch , John Cho, Ngaire Underhill, Richard DeLaura

abstract

En route sector capacity is determined mainly by controller workload. The Federal Aviation Administration’s (FAA) current operational capacity model provides traffic alert thresholds based on hand-off workload. It provides accurate estimates for most sectors, but tends to over-estimate capacity in both small and large sectors, since it does not account for conflict-resolution and recurring workload. Because of those omissions it cannot be applied to benefits analysis of proposed air traffic management workload reduction initiatives. Furthermore, it cannot be extended to estimate capacity when hazardous weather increases all workload types. Previously, we developed a model that accounts for all task types. Extensions of the model to handle hazardous weather introduced additional parameters. We determine the workload parameters by regressing against busy-day peak traffic counts for en route sectors. In this paper we analyze the impact of parameter ambiguity on benefit analyses. We also present the results of a new regression against a comprehensive traffic database in the United States that confirms earlier trial findings based on limited data. Finally, we modify the weather-impacted sector capacity model to provide a more stable normalized capacity measure and illustrate its potential application to operational sector capacity forecasts.
pdf logo image pdf logo image Dynamic Airspace and Capacity Management
26 230 Designing Coordinated Initiatives for Strategic Traffic Flow Management
Author: Christine Taylor , Craig Wanke

abstract

This paper develops an approach for automation-assisted design of strategic traffic management strategies. The goal of strategic traffic flow management is to develop traffic management initiatives that mitigate potential large-scale congestion in the future when the imbalance cannot be effectively managed with tactical measures. Thus, despite the inherent uncertainties in the demand and capacity forecasts at longer look-ahead times, decisions regarding National Airspace-wide behavior are necessary. As such it is desirable to develop a decision support system that provides quantitative feedback on predicted traffic impact and aids in developing effective solutions. This paper proposes a framework to address this need by simulating and evaluating the effectiveness of proposed strategies across a variety of metrics. Using a realistic example taken from historic data, we explore the traffic management design space by varying the parameters associated with different management initiatives. The results are compared to those obtained using a naïve heuristic optimization approach and recommendations on requirements for future design approaches are provided.
pdf logo image pdf logo image Network and Strategic Traffic Flow Optimization
27 232 Operational Evaluation of Dynamic Weather Routes at American Airlines
Author: David McNally , Kapil Sheth, Chester Gong, Mike Sterenchuk, Scott Sahlman, Susan Hinton, Chuhan Lee, Fu-Tai Shih, , ,

abstract

Dynamic Weather Routes (DWR) is a search engine that continuously and automatically analyzes in-flight aircraft in en route airspace and proposes simple route amendments for more efficient routes around convective weather while considering sector congestion, traffic conflicts, and active Special Use Airspace. NASA and American Airlines (AA) are conducting an operational trial of DWR at the AA System Operations Center in Fort Worth, Texas. The trial includes only AA flights in Fort Worth Center airspace. Over the period from July 31, 2012 through October 31, 2012, 45% of routes proposed by DWR and evaluated by AA users, air traffic control coordinators and flight dispatchers, were rated as acceptable as proposed or with some modifications. The wind-corrected potential flying time savings for these acceptable routes totaled 470 flying min. DWR identified reroutes offering an additional 4,066 min of potential flying time savings for AA flights, but these routes were not evaluated due to staffing limitations. A sector congestion analysis shows that in only three out of 83 DWR routes rated acceptable by AA staff were the flights predicted to fly through a congested sector inside of 30 min downstream of present position. This shows that users considered sector congestion data provided by DWR automation and in nearly all cases did not accept routes through over-capacity sectors.
pdf logo image pdf logo image Weather in ATM
28 233 Regression Analysis of Top of Descent Location for Idle-thrust Descents
Author: Laurel Stell , Jesper Bronsvoort, Greg McDonald

abstract

In this paper, multiple regression analysis is used to model the top of descent (TOD) location of user-preferred descent trajectories computed by the flight management system (FMS) on over 1000~commercial flights into Melbourne, Australia. In addition to recording TOD, the cruise altitude, final altitude, cruise Mach, descent speed, wind, and engine type were also identified for use as the independent variables in the regression analysis. Both first-order and second-order models are considered, where cross-validation, hypothesis testing, and additional analysis are used to compare models. This identifies the models that should give the smallest errors if used to predict TOD location for new data in the future. A model that is linear in TOD altitude, final altitude, descent speed, and wind gives an estimated standard deviation of 3.9~nmi for TOD location given the trajectory parameters, which means about 80\% of predictions would have error less than 5~nmi in absolute value. This accuracy is better than demonstrated by other ground automation predictions using kinetic models. Furthermore, this approach would enable online learning of the model. Additional data or further knowledge of algorithms is necessary to conclude definitively that no second-order terms are appropriate. Possible applications of the linear model are described, including enabling arriving aircraft to fly optimized descents computed by the FMS even in congested airspace.
pdf logo image pdf logo image Trajectory and Queue Management
29 237 Usability Evaluation of the Spot and Runway Departure Advisor (SARDA) Concept in a Dallas/Fort Worth Airport Tower Simulation
Author: Miwa Hayashi , Ty Hoang, Yoon Jung, Waqar Malik, Hanbong Lee, Victoria Dulchinos

abstract

Spot and Runway Departure Advisor (SARDA) is a decision-support tool proposed to aid air traffic control tower controllers in reducing taxi delay and optimizing the runway sequence. The purpose of the present paper was to evaluate the tool’s usability to ensure that its claimed performance benefits are not being realized at the cost of increasing the work burden on controllers. The study analyzed workload ratings and questionnaire responses collected during a human-in-the-loop simulation experiment and assessed the effects of the SARDA advisories on the controllers’ cognitive resources (e.g., workload, spare attention) and satisfaction. The results showed that SARDA reduced the controllers’ workload and increased their perceived spare attention. SARDA also made workload and attention levels less susceptible to the effects of increases in the traffic load. The questionnaire responses suggested that the controllers generally were satisfied with the ease of use of the tool and the intended benefits of the SARDA concept, but with slight reservations. Sharing high-level reasoning behind SARDA’s optimization process with the controllers may help the concept to gain more trust from them.
pdf logo image pdf logo image Human Factors
30 239 Climate cost functions as a basis for climate optimized flight trajectories
Author: Christine Frömming , Volker Grewe, Patrick Jöckel, Sabine Brinkop, Simone Dietmüller, Hella Garny, Michael Ponater, Eleni Tsati, Sigrun Matthes

abstract

Climate cost functions are a measure for the climate impact of individual aviation emissions in dependency of the emission location, altitude, time and weather situation during emission. To determine the climate change contribution due to an individual emission as function of emission location, altitude and time, four-dimensional climate cost functions are computed. Therefore the ECHAM5/MESSy Atmospheric Chemistry model (EMAC) has been employed. The emitted trace species are transported by means of the Lagrangian advection scheme ATTILA. To evaluate the climate impact from several emission locations and dates within one simulation, a new submodel (AIRTRAC) has been developed. Chemical changes of ozone, methane and water vapor, as well as contrail formation and aging caused by a particular emission are computed directly on air parcels. For each emission location and date, the changes of radiatively active species and the corresponding radiative forcings are computed, from which the climate cost functions are derived. The climate cost functions form the basis for the optimization of air traffic flight trajectories with respect to minimum climate impact. Typical weather situations are considered and differences in climate impact are investigated. The North Atlantic flight corridor is considered for route optimization.
pdf logo image pdf logo image Environment and Energy Efficiency
31 242 Controlled Time of Arrival Feasibility Analysis
Author: David De Smedt , Jesper Bronsvoort, Greg McDonald

abstract

Previous research studies and operational trials have shown that using the airborne Required Time of Arrival (RTA) function, an aircraft can individually achieve an assigned time to a metering or merge point accurately. This study goes a step further and investigates the application of RTA to a real sequence of arriving aircraft into Melbourne Australia. Assuming that the actual arrival times were Controlled Time of Arrivals (CTAs) assigned to each aircraft, the study examines if the airborne RTA solution would work. Three scenarios were compared: a baseline scenario being the actual flown trajectories in a two hour time-span into Melbourne, a scenario in which the sequential landing slot times of the baseline scenario were assigned as CTAs and a third scenario in which the landing slots could be freely redistributed to the inbound traffic as CTAs. The research found that pressure on the terminal area would sometimes require aircraft to lose more time than possible through the RTA capability. Using linear holding as an additional measure to absorb extensive delays, up to 500NM (5%) of total track reduction and 1300kg (3%) of total fuel consumption could be saved in the scenario with landing slots freely distributed as CTAs, compared to the baseline scenario. Assigning CTAs in an arrival sequence requires the ground system to have an accurate trajectory predictor to propose additional delay measures (path stretching, linear holding) if necessary. Reducing the achievable time window of the aircraft to add control margin to the RTA function, had a negative impact and increased the amount of intervention other than speed control required to solve the sequence. It was concluded that the RTA capability is not a complete solution but merely a tool to assist in managing the increasing complexity of air traffic.
pdf logo image pdf logo image Trajectory and Queue Management
32 243 4-D Trajectory Optimizers for Conflict Avoidance Using Speed Advisories
Author: Arthur Richards , Oliver Turnbull

abstract

This paper extends 4-D trajectory optimizers to resolve conflicts through “speed advisories”, separating high-level decision making from the detailed trajectory optimization. Details of Mixed Integer Linear Programming (MILP) and collocation optimizers are briefly reviewed before the additional constraints are developed to force resolution only through speed changes. Results for a multi-sector area over Wales and North- West England illustrate how the method can be used. A brief evaluation of the computational complexity of the method is shown. This paper describes results from the SUPEROPT project that is part of SESAR WorkPackage E, which is addressing long-term and innovative research.
pdf logo image pdf logo image Separation
33 244 Markov Model for Cost and Benefits Analysis of Air Traffic Technologies
Author: Vineet Mehta , Scot Campbell, Kavitha Chandra, Ngaire Underhill, Richard DeLaura

abstract

A critical step in the design and development of new tools and systems for air traffic management is the estimation of potential benefits of the added technology. The current methodology of estimating the added benefit of a new tool is based on a combination of simulation and field observations, requiring either an extensive model of the system or a fielded prototype. This paper contributes a Markov model for benefits estimation, which allows for quick assessment of benefit uncertainty and rapid evaluation of different operational scenarios. In this paper, a Markov model is employed to estimate the benefits of a strategic departure management tool. The model probabilities are derived from a historical archive of Route Availability Planning Tool (RAPT). Monte Carlo simulations are performed to estimate the range of benefit for uncertainties in model parameters and technology performance accuracy. Using this model we also provide an illustration of how different decision procedures can be accommodated, and their impact on benefits.
pdf logo image pdf logo image ATM Performance Measurement and Management
34 245 Automated Integration of Arrival/Departure Schedules
Author: Paul Diffenderfer , Zheng Tao, Gaea Payton

abstract

At airports where there is a dependency between arrival and departure operations, existing procedures often result in inefficient coordination between the arriving and departing flights, compromising airport throughput. With two key changes the throughput can be improved without affecting safety: integrating the arrival and departure streams and increasing communication between the Tower and the Terminal Radar Approach Control (TRACON). The airports include those that conduct arrival and departure operations to crossing or converging runways, or conduct same runway operations such as Ronald Reagan Washington National Airport (KDCA) or London’s Gatwick Airport (EGKK). Typically at these types of airports, a static interval is set between arriving flights so that the airport’s Tower Controller can depart aircraft in the gaps. The static interval is maintained even without any waiting departures and is usually adjusted only with verbal coordination between the Tower and TRACON. At these airports, throughput can be improved by providing dynamic spacing guidance to Approach Controllers that accounts for the departure queue. The MITRE Corporation’s Center for Advanced Aviation System Development (CAASD) is investigating methods to provide automated arrival spacing guidance. A research prototype called the Automated Integration of Arrival/Departure Schedules provides automated arrival spacing guidance for Approach Controllers. The guidance communicates arrival intervals depending on the type and order of departure aircraft queued at or taxiing to the dependent runway. It provides an indication to use minimum arrival spacing when there are no queued departures. MITRE has conducted fast-time and Human-in-the-Loop (HITL) simulations to assess the feasibility of this solution in terms of adherence to spacing guidance and workload impacts. Controllers achieved a high level of conformance to guidance and workload levels were within a safe range. This paper reviews the shortfalls of relevant current operations, the proposed solution and prototype,
pdf logo image pdf logo image Air Ground Integrated Concepts
35 246 Computational Red Teaming for Correction of Traffic Events in Real Time Human Performance Studies
Author: Hussein Abbass , Rubai Amin, Jiangjun Tang, Mohamed Ellejmi, Stephen Kirby

abstract

In human performance studies using real-time air traffic simulation, the human performance analyst faces challenges to ensure that certain events and scenario characteristics will occur during the experiments. While some events, such as specific categories of conflicts, can be designed in the scenario, the interaction of the humans can undo these events early in the simulation. This poses a challenge and the objective of the experiment can become difficult to meet. Computational Red Teaming (CRT) is a computational environment that attempts to play devil advocates. A CRT is designed and used in this paper to monitor, re-steer and adjust traffic events in these real-time air-traffic simulation environments. The approach was able to correct events successfully, when possible. In situations were the time to correct events is greater than the time remaining for the experiments or when the constraints of the scenario do not allow certain steering requests to be issued or accepted, those events can't be recreated. Therefore, analysts are advised to avoid designing events closer to the end of the session to allow for the CRT to take corrective actions if the session does not evolve as planned.
pdf logo image pdf logo image Human Factors
36 247 Optimizing the Next Generation Collision Avoidance System for Safe, Suitable, and Acceptable Operational Performance
Author: Jessica Holland , Mykel Kochenderfer, Wesley Olson

abstract

The Traffic Alert and Collision Avoidance System (TCAS) is mandated worldwide on large commercial aircraft and has been shown to substantially reduce the risk of mid-air collision. However, the logic used to select pilot advisories is difficult to modify and does not easily support new surveillance inputs. The next generation system, called Airborne Collision Avoidance System (ACAS X), currently addresses many of the design limitations of TCAS. ACAS X is optimized with respect to a cost function. The system was initially optimized to increase safety and decrease alerts. Recent work has focused on tuning ACAS X to also meet operational suitability and pilot acceptability performance metrics. An iterative tuning process reduced the operational impact on the air traffic system and improved acceptability of alerts. This paper summarizes a fifteen-month effort that resulted in substantial improvements. Compared with TCAS, ACAS X reduces collision risk by 59%, lowers the alert rate by 59%, and issues 28% fewer disruptive alerts. ACAS X also resolves encounters with simpler alert sequences and issues less than half as many reversal and crossing advisories.
pdf logo image pdf logo image Safety and Resilience
37 249 Initial 4D Trajectory Management Concept Evaluation
Author: Laurence Mutuel  

abstract

Results are presented from the evaluation of Initial 4D (I4D) Trajectory Management concept developed under the Single European Sky ATM Research (SESAR) framework as one of the six key features associated with Time-Based Operations. The objective of this first step is to synchronize trajectory information between Air Traffic Controllers (ATC) and their supporting automation and the flight crew/aircraft avionics so that the arrival sequence can be optimized. The shared common view of the trajectory is translated into an agreed 2D route and a time constraint. The implementation of the I4D concept is distributed over aircraft avionics systems and ATM automation systems across navigation and communication domains. The I4D first flight trial was performed on 10 February 2012 following a series of validation exercises in simulator to assess the concept and prepare all actors for the flight. The Airbus A320 Test Aircraft took off from Toulouse-Blagnac airport (France) for Stockholm Arlanda (Sweden) and tested all I4D key elements over six flight legs. The avionics modifications included an advanced Flight Management System (FMS), an onboard digital communication unit and the cockpit displays; ATM automation systems supported Ground-Ground coordination among the relevant Air Navigation Service Providers (ANSPs) and integrated down-linked aircraft trajectory information. Avionics interoperability was tested through the use of two independently developed FMS. The technical feasibility of the concept was demonstrated from both the crew and the controllers standpoints. In addition, key performance requirements such as tolerance on the mutually agreed time constraint was met with a significant margin on all legs where it was applied. The analysis of the validation exercise led to the publication of a series of recommendations for systems modifications, further investigations to be performed in flight test or simulation and for short-term actions in datalink communication and navigation standardization groups.
pdf logo image pdf logo image Air Ground Integrated Concepts
38 255 Modeling Delivery Accuracy for Metering Operations to Support RNAV Arrivals
Author: Ian Levitt , Lesley Weitz, Michael Castle

abstract

Interval Management (IM) is a future airborne spacing concept that aims to provide more precise inter-aircraft spacing to yield throughput improvements and greater use of fuel-efficient trajectories in arrival and approach environments. To participate in an IM operation, an aircraft must be equipped with avionics that provide speeds to achieve and maintain a desired spacing interval relative to another aircraft. It is not expected that all aircraft will be equipped with the necessary avionics, but rather that IM fits into a larger arrival management concept developed to support the broader mixed-equipage environment. Arrival management concepts are comprised of three parts: a ground-based sequencing and scheduling function to develop an overall arrival strategy, ground-based tools to support the management of aircraft to that schedule, and the IM tools necessary for the IM operation (i.e., ground-based set-up, initiation, and monitoring, and the flight-deck tools to conduct the IM operation). The Federal Aviation Administration is deploying a near-term ground-automation system to support metering operations in the National Airspace System, which fall within the first two components of the arrival management concept. The near-term system will include sequencing and scheduling functions and tools to help air traffic controllers in managing aircraft to meet their scheduled times of arrival (STAs) at meter points. This paper presents a methodology for determining the required delivery accuracy at the meter points in order to achieve desired flow rates, adequate separation at the meter points, and to enable aircraft to meet their STAs while remaining on their RNAV arrivals, which will reduce costly vectoring and holding. An example based on operations at Phoenix airport is presented to illustrate the analysis framework in a real-world context.
pdf logo image pdf logo image ATM as a Complex System
39 263 Synchronization Likelihood in Aircraft Trajectories
Author: Massimiliano Zanin  

abstract

In the continuous effort for ensuring increasing levels of safety, it is of utmost importance to understand the reasons behind the occurrence of operational errors. In this contribution, we propose the use of the Trajectory Synchronization Likelihood metric for the analysis of two types of events: situations resulting in a reduced separation between aircrafts, and situations that might have resulted in similar conditions but were solved on time. Results indicate that unsolved events are associated with highly synchronized pairs of aircraft, which have been deviated from the usual expected trajectories. This opens new way for the development of more effective automated safety systems, capable of detecting in real time events that are known to have a high probability of resulting in a conflict.
pdf logo image pdf logo image ATM as a Complex System
40 264 A New Framework for Solving En-Route Conflicts
Author: Cyril Allignol , Nicolas Barnier, Nicolas Durand, Jean-Marc Alliot

abstract

The en-route conflict resolution problem has been modeled in many different ways, generally depending on the tools that were proposed to solve it. For instance, with purely analytic mathematical solvers, models tend to be very restrictive (constant speeds, linear trajectories...) to respect the inherent limitations of the technology. This paper introduces a new framework that separates the model from the solver so as to be able to: first, enhance the model with as many refinements (e.g. wind and trajectory uncertainties) as necessary to comply with operational constraints; second, compare different resolution methods on the same data, which is one of the crucial aspects of scientific research. To this aim, our framework can generate a benchmark of conflict resolution problems built with various scenarios involving a given number of aircraft, different levels of uncertainties and number of maneuvers. We then compare two different optimization paradigms, Evolutionary Algorithm and Constraint Programming, which can efficiently solve difficult instances in near real time, to illustrate the usefulness of our approach.
pdf logo image pdf logo image Separation
41 265 Assuring Safety of NextGen Procedures
Author: Matthew Placke , Nancy Leveson, Cody Fleming

abstract

This paper introduces an innovative approach to analyzing safety in the next generation of air traffic management systems. The new methodology is applicable during the entire design life-cycle from early concept selection through final certification. Hazard analysis of a completed NextGen concept, In-Trail Procedure, is demonstrated as well as use in the early concept development of Trajectory Based Operations.
pdf logo image pdf logo image Safety and Resilience
42 270 Effect of radii of exemption on ground delay programs with operating cost based cruise speed reduction
Author: Luis Delgado , Xavier Prats

abstract

When a ground delay program (GDP) is defined, a radius of exemption is typically set to exclude from having to realize ground delay aircraft departing from greater distances than the selected radius distance. A trade-off exists when defining this radius: big radii distribute the required delay among more aircraft and reduce the airborne holding delay close to the destination airport, while the probability to realize unnecessary delay increases if the program is canceled before planned. In order to overcome part of this drawback, a cost based cruise speed reduction strategy aiming at realizing airborne delay was suggested by the authors in previous publications. By flying slower, at a specific speed, aircraft that are airborne can recover part of their initially assigned delay without incurring extra cost if the GDP is canceled before planned. In this paper, the effect of the exemption radius is assessed when applying this strategy and a case study is presented by analyzing all the GDPs that took place at Chicago O'Hare International Airport during one year. Results show that by the introduction of this technique, more delay can be saved. Thus, it is possible to define larger radii of exemption, reducing partially the drawbacks associated with smaller radii.
pdf logo image pdf logo image Network and Strategic Traffic Flow Optimization
43 274 Simulations of Continuous Descent Operations with Arrival-Management Automation and mixed Flight-Deck Interval Management Equipage
Author: Todd Callantine , William Johnson, John Robinson,

abstract

Air traffic management simulations conducted in the Airspace Operations Laboratory at NASA Ames Research Center have addressed the integration of trajectory-based arrival-management automation, controller tools, and Flight-Deck Interval Management avionics to enable Continuous Descent Operations (CDOs) during periods of sustained high traffic demand. The simulations are devoted to maturing the integrated system for field demonstration, and refining the controller tools, clearance phraseology, and procedures specified in the associated concept of operations. The results indicate a variety of factors impact the concept’s safety and viability from a controller’s perspective, including en-route preconditioning of arrival flows, useable clearance phraseology, and the characteristics of airspace, routes, and traffic-management methods in use at a particular site. Clear understanding of automation behavior and required shifts in roles and responsibilities is important for controller acceptance and realizing potential benefits. This paper discusses the simulations, drawing parallels with results from related European efforts. The most recent study found en-route controllers can effectively precondition arrival flows, which significantly improved route conformance during CDOs. Controllers found the tools acceptable, in line with previous studies.
pdf logo image pdf logo image Air Ground Integrated Concepts
44 277 Performance based approach to investigate resilience and robustness of an ATM System
Author: Olga Gluchshenko , Peter Foerster

abstract

Resilience is a fundamental property of the natural ecosystem that enables quick recovery after numerous disturbances occurring frequently. This vital ability of the ecosystem makes resilience a very desirable property of man-made socio-technical systems. The European ATM System, which in future will be set up to achieve the performance targets given by SESAR, is such a socio-technical system. A lot of contradictory definitions of the term resilience in different domains fall into two big categories with semantical meanings of "resilience" or "robustness". Currently, in the ATM Context exists a definition of resilience from the safety science perspective only. This paper will apply a new definition of resilience and robustness on the ATM System to help realizing the agreed performance targets under the influence of disturbances. To follow this approach, a clear differentiation between both terms has to be carried out. The aim of this conceptual paper is to present a developed framework that incorporates concepts of robustness, resilience and relevant terms such as disturbance, stress and perturbation. This is complemented by an according decision-making chain. Furthermore, this paper suggests some qualitative and quantitative forms of measures of resilience and robustness and provides a structured approach for the investigation of both terms. By incorporating the presented terminology in order to identify new methods to increase resilience or robustness, a new modeling approach will be introduced. This will be complemented by an according algorithm. The structure of the modeling approach divides the ATM System into two - a sociological and a physical dimensions. The sociological dimension shall enable to reveal improvement potential in the context of operational rules of particular stakeholders, adapting resources and finding alternative ways to achieve the given performance targets.
pdf logo image pdf logo image Safety and Resilience
45 281 3D-Precision Curved Approaches: A Cockpit View on ATM
Author: Robert Geister , Thomas Dautermann, Vilmar Mollwitz, Christian Hanses, Hayung Becker

abstract

Pre-defined curved approach procedures represent an essential for noise abatement and may reduce the risk of controlled flight into terrain (CFIT) for today’s aviation considerably. In addition, a Ground Based Augmentation System (GBAS) supports accuracy and precision of the desired flight path. While the lateral guidance during current curved approach procedures is usually based on a position solution provided by satellite navigation systems in conjunction with inertial navigation systems, the vertical guidance is still based on measurements of a barometric altimeter. This type of approach with vertical guidance is supposed to enhance the situational awareness for pilots compared to non-precision approach procedures and reduce the risk for controlled flight into terrain. However, the accuracy of the barometric vertical guidance is inferior compared to precision approach procedures, temperature dependent and require the correct pressure setting for each approach in the aircraft. Therefore, novel curved approach procedures are supposed to rely solely on satellite navigation augmented by either a ground based or satellite based system and only optionally by inertial measurement systems. Such coupled (hybrid INS and GNSS) systems are usually highly integrated and monitored by a flight management system. Therefore, the requirements for the equipment of aircraft that are conducting such approach procedures are very stringent. Using only GBAS could relax those requirements. In this work, an option for precision curved approach procedures was investigated and tested in flight trials. This option is based on a GBAS. In general, different possibilities are imaginable to enable GBAS based curved approaches. For instance, GBAS could only serve as means to enhance the navigation performance to achieve stringent RNP requirements. Or GBAS could serve as the sole means to enable a curved approach. This option is described in this paper.
pdf logo image pdf logo image Enhanced Surveillance and Navigation
46 283 Enhancing Cost-Efficiency and Reducing Capacity Shortages: Strategic Planning and Dynamic Shift Management
Author: Gonzalo Tobaruela , Arnab Majumdar, Peter Hendrickx, Washington Ochieng, Wolfgang Schuster

abstract

This paper analyses the relationship between capacity and cost-efficiency at an en-route Air Traffic Control Centre level. It develops a set of cost-efficiency metrics to describe the centre planning process, and compares these results to cost-efficiency values. In order to understand the effect of the new tools and procedures implemented at the centre on its cost-efficiency, statistical analysis of the operational data before and after implementation is undertaken. The results show that the introduction of a dynamic shift management enabled by staff planning automation tools, along with a flexible roster and an appropriate planning process can simultaneously enhance capacity and cost-efficiency. These improvements are mapped to the SESAR Operational Improvements, to assess the feasibility of the programme to achieve its capacity and cost-efficiency improvement targets.
pdf logo image pdf logo image ATM Performance Measurement and Management
47 285 Analysis of Airspace Complexity Factors’ Capability to Predict Workload and Safety Levels in the TMA
Author: Markus Vogel , Kati Schelbert, Trevor Kistan, Hartmut Fricke

abstract

Research on airspace complexity metrics with the aim of characterizing traffic with respect to air traffic controllers’ cognitive workload has been ongoing for the last 40years (complex-ity factors, dynamic density). Nevertheless, simplesector load based on aircraft count remains the key planning figure in ATM & ATFM. The proposed complexity factors lack a commonmodel of causation (pre, peri, post controller intervention), which leads to case-specific workload dependencies. Motivated by EUROCON-TROL’s research in Single European Sky and recent THALES advances studying the introduction of dynamic density metrics in an operational ATFM environment, this study analyzes the predictive capabilities of complexity metrics towards (1) controller workload and (2) the level of safety (collision risk). By means of average-filtering and time-shifting, a linear prediction model’s coefficient of determination was improved significantly. For simulated controller workload, a local optimum is situated at the current timeframe (r² ~ 0.7). For radar-data based collision risk, the bestprediction looks 130 s into the future (r² ~ 0.5). This observation is coherent with the findings for simulation-based collision risk (150 s, r² ~ 0.5).
pdf logo image pdf logo image Dynamic Airspace and Capacity Management
48 288 Data-driven modeling of systemic delay propagation under severe meteorological conditions
Author: Pablo Fleurquin , Jose J Ramasco, Victor M Eguiluz

abstract

The upsetting consequences of weather conditions are well known to any person involved in air transportation. Still the quantification of how these disturbances affect delay propagation and the effectiveness of managers and pilots interventions to prevent possible large- scale system failures needs further attention. In this work, we employ an agent-based data-driven model developed using real flight performance registers for the entire US airport network and focus on the events occurring on October 27 2010 in the United States. A major storm complex that was later called the 2010 Superstorm took place that day. Our model correctly reproduces the evolution of the delay-spreading dynamics. By considering different intervention measures, we can even improve the model predictions getting closer to the real delay data. Our model can thus be of help to managers as a tool to assess different intervention measures in order to diminish the impact of disruptive conditions in the air transport system.
pdf logo image pdf logo image ATM as a Complex System
49 292 Environmental Impacts of Continuous-descent Operations in Paris and New York Regions: Isolation of ATM/Airspace Effects and Comparison of Models
Author: Terence Thompson , Sofia Souihi, Bruno Miller, Charles Murphy, Stephen Augustine, Tyler White

abstract

In order to better understand SESAR and NextGen metrics and models for environmental impact assessment, we analyze the differences in effects of a selected ATM improvement (CDO/CDA) on European and U.S. performance using similar regional data sets and the same analytical methods and models. We have: (1) analyzed one day of traffic for both the Paris (CDG and ORY) and New York regions (LGA, JFK, and EWR); (2) compared the relative benefit pools for reduction of environmental impacts (fuel/CO2, noise, and NOx) in the two regions; (3) estimated the fuel, noise, and air-quality impacts in the two regions using the same modeling techniques; and (4) compared the fuel estimates obtained from 3 different models (NIRS, AEM-III, and IFSET). We find that both absolute and relative CDO/CDA benefits differ substantially for the Paris and New York regions due to significant differences in current traffic intensity, as well as the current distribution of level segments in flight trajectories. The effects estimated focus only on ATM- related trajectory changes, with fleet-composition effects removed from the analysis.
pdf logo image pdf logo image Environment and Energy Efficiency
50 299 Pilot and Controller Evaluations of Separation Function Allocation in Air Traffic Management
Author: David Wing , Thomas Prevot, Timothy Lewis, Lynne Martin, Sally Johnson, Christopher Cabrall, Sean Commo, Jeffrey Homola, Manasi Sheth-Chandra, Joey Mercer, Susan Morey

abstract

Two human-in-the-loop simulation experiments were conducted in coordinated fashion to investigate the allocation of separation assurance functions between ground and air and between humans and automation. The experiments modeled a mixed-operations concept in which aircraft receiving ground-based separation services shared the airspace with aircraft providing their own separation service (i.e., self-separation). Ground-based separation was provided by air traffic controllers without automation tools, with tools, or by automation with controllers in a managing role. Airborne self-separation was provided by airline pilots using self-separation automation enabled by airborne surveillance technology. The two experiments, one pilot-focused and the other controller-focused, addressed selected key issues of mixed operations: the impact of mixed operations on controller performance at four stages of NextGen implementation and the limits to which pilots with automation tools could take full responsibility for separation from ground-controlled aircraft. Results indicate that the presence of self-separating aircraft had little impact on the controllers’ ability to provide separation services for ground-controlled aircraft. Performance was best in the most automated environment in which all aircraft were data communications equipped, ground-based separation was highly automated, and self-separating aircraft had access to trajectory intent for all aircraft. In less automated environments, reduced trajectory intent exchange and manual air traffic control limited safely achievable throughput and negatively impacted the maneuver efficiency of self-separating aircraft through high-density airspace. Flight crews of self-separating aircraft prevented separation loss in all conflicts with detection time greater than one minute. Pilots indicated a preference for at least five minute’s alerting notice and trajectory intent information on all aircraft. When ground-managed aircraft intent was available, self-separating aircraft benefited from fewer conflict alerts and fewer required deviations from trajectory-based operations.
pdf logo image pdf logo image Air Ground Integrated Concepts
51 300 Estimating Current & Future System-Wide Benefits of Airport Surface Congestion Management
Author: Tom Reynolds , Michael McPartland

abstract

Air traffic is expected to continue to grow in the future and improved methods for dealing with the increased demand on the system need to be designed and implemented. One method for reducing airport congestion is surface congestion management. The concept generally involves determining a limit to how many aircraft can efficiently taxi to departure runways, and then holding “excess” aircraft at the gate or in the ramp area with engines off instead of releasing them onto the active movement area during periods of high departure demand. This results in reduced congestion and taxi time, with jet fuel and emissions savings. In order to determine the appropriateness of deploying surface congestion management, estimates of the potential benefits at a wide range of airports into the future are necessary to assist with investment analysis decisions. To overcome challenges associated with the resulting wide spatial and temporal scope, a multi-fidelity modeling approach has been developed where high fidelity models are developed and executed for a small number of key airports, and these are used to inform, validate and extrapolate medium and low fidelity models which are applied to ever-broader sets of airports. Application of these models produce estimates of fuel savings from surface congestion management of 2.2-3.9 billion gallons across the top 35 US airports over the period 2010-2030, with a value of $5.5-9.5 billion. Additional benefits in the form of reduced climate and air quality-impacting emissions have also been estimated to have similar orders of magnitude to the fuel savings.
pdf logo image pdf logo image Trajectory and Queue Management
52 301 Airport Characterization for the Adaptation of Surface Congestion Management Approaches
Author: Tom Reynolds , Thomas Teller, Seth Troxel,

abstract

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.
pdf logo image pdf logo image Environment and Energy Efficiency
53 302 Modeling potential hazards within agent-based safety risk analysis
Author: Henk Blom , Sybert Stroeve, Tibor Bosse

abstract

One of the first steps in safety risk assessment of an ATM operation is to identify as many potential hazards as is possible. All these potential hazards have to be analysed upon there possible contribution to safety risk of the operation considered. In an agent-based safety risk assessment of ATM operations there are two approaches towards the assessment of the safety risk impacts of hazards. The direct way is to incorporate the hazard in the agent-based model, and to assess this agent-based model on safety risk by conducting Monte Carlo simulations. The alternative is to avoid the modelling of a potential hazard in the agent-based model, and instead assess the impact of the hazard on safety risk through sensitivity analysis and bias and uncertainty assessment. Because agent-based modelling and simulation of hazards may reveal emergent behaviour that remains invisible through sensitivity analysis, there is a need to know for each hazard how to model it in an agent-based approach. Hence the aim of this paper is to identify the types of agent-based model constructs for potential hazards in ATM. This study leads to the identification of 38 model constructs that are able to capture about 98% of the hazards considered in an agent-based model. The paper also shows how these agent-based model constructs relate to modelling approaches in various other aviation domains, such as system reliability, human performance simulation, Human Reliability Analysis, and aircraft trajectory simulation. The model construct ‘multi-agent situation awareness’ captures by far the highest percentage of hazards (41%). This model construct does not correspond to any of these four well established modelling areas.
pdf logo image pdf logo image Safety and Resilience
54 315 Strategic Planning in Air Traffic Control as a Multi-objective Stochastic Optimization Problem
Author: Gaétan Marceau , Pierre Sav´eant, Marc Schoenauer

abstract

With the objective of handling the airspace sector congestion subject to a continuously growing air traffic, we suggest to create a collaborative working plan during the strategic phase of air traffic control The plan obtained via new decision- support presented in this article consists in a schedule for controllers which specifies time of overflight on the different waypoints of the flight plans. In order to do it, we believe that the decision-support tool shall model directly the uncertainty at a trajectory level in order to propagate the uncertainty to the sector level. Then, the probability of congestion for any sector in the airspace can be computed. Since air traffic regulations and sector congestion are antagonist, we designed and implemented a multiobjective optimization algorithm for determining the best trade-off between these two criteria. The solution comes up as a set of alternatives for the multi-sector planner where the severity of the congestion cost is adjustable. In this paper, the Non- dominated Sorting Genetic Algorithm (NSGA-II) was used to solve an atificial benchmark problem involving 24 aircraft and 11 sectors, and is able to provide a good approximation of the Pareto front.
pdf logo image pdf logo image Network and Strategic Traffic Flow Optimization
55 316 Boarding on the critical path of the turnaround
Author: Michael Schultz , Thomas Kunze, Hartmut Fricke

abstract

Time-efficient boarding strategies are an essential for reliable turnaround progress, since it always on the time critical path. Since the boarding time mainly depends on the amount of passengers, arrival rate, passenger boarding sequence and aircraft type we investigate different boarding scenarios on three reference aircraft: Airbus A320 (single aisle), Boeing B777 and Airbus A380 (both with a twin aisle configuration). The microscopic model of the passenger behavior is based on the asymmetric simple exclusion process (ASEP), where the motion is defined as a one dimensional, stochastic, and time/space discrete process. The analyses of appreciable boarding strategies are focusing on expected time and standard deviation of the boarding. In the context of both reliable boarding progress and delay compensation during the turnaround our results emphasize the use of an additional door (20-25% savings) followed by a change of the boarding strategy (10-15% savings) or application of different seat layouts (3 % savings). First field trials with Airberlin confirm our results.
pdf logo image pdf logo image Integrated Airport/Airside Operations
56 317 Estimating Airspace Capacity Based on Risk Mitigation Metrics
Author: Husni Idris , Ni Shen

abstract

Airspace capacity is a key parameter in the air traffic management system. Numerous metrics for estimating it have been proposed including simple ones such as aircraft count and sophisticated ones representing traffic complexity. In this paper, an approach is presented for estimating airspace capacity that addresses two main factors: (1) the risk element in determining capacity, represented by the tradeoff between capacity and the ability to mitigate the risk of violating traffic management constraints, and (2) the cognitive element in determining capacity, represented by the control strategy used by different control schemes such as human control, automation control, or automation assisted control. The approach is demonstrated using a risk mitigation metric, called adaptability, which estimates the number of feasible trajectories that are available to an aircraft, using a certain control strategy, to avoid violating traffic management constraints. Using this metric, the tradeoff between adaptability and capacity to absorb delay that exists in current human control behavior was identified through analysis of historical track data of two airspace sectors. This metric was also used to compare alternative control strategies in a simulated metering situation involving separation assurance and meeting required times of arrival at a fix. The comparison highlighted the higher capacity and adaptability levels that can be achieved with more efficient control strategies relative to human control. Thus, the presented analysis demonstrates the potential of risk mitigation metrics such as adaptability to estimate airspace capacity limits that achieve desired levels of risk mitigation under different control strategies and automation schemes.
pdf logo image pdf logo image ATM Performance Measurement and Management
57 318 Ground Delay Program Decision-making using Multiple Criteria: A Single Airport Case
Author: Yi Liu , Mark Hansen

abstract

In this paper, we develop GDP models using continuum approximation. Both early GDP cancellation and GDP extensions are considered in the models. We then identify and define four performance criteria for Ground Delay Program (GDP): capacity utilization, predictability, efficiency and equity. Using the proposed GDP models, we represent the trade-offs between the performance goals and relate these to the GDP decisions on: the GDP planned clearance time, the GDP scope and the choice on GDP early cancellation. Each flight operator may prefer a different point on the performance trade-off curves and correspondingly opt for different GDP plans. The decision-making process is formed as a utility optimization problem in our work. Specifically, we employ a linear utility function to illustrate how the trade-off curves could be used by flight operators to select their preferred GDP decisions. The research would lead to improved GDP decision-making, in which traffic managers and flight operators can make informed tradeoffs based on their assessment of the importance of different performance criteria
pdf logo image pdf logo image ATM Performance Measurement and Management
58 320 A Methodology to Assess the Safety of Aircraft Operations when Aerodrome Obstacle Standards cannot be met
Author: Hartmut Fricke ,

abstract

When Aerodrome Obstacle Standards cannot be met as a result of urban or technical development, EASA in-line with ICAO allows proving an equivalent level of safety by carrying out an aeronautical study. However, detailed guidance in doing so is not provided. This paper aims at filling this gap with a proposed safety assessment methodology to value obstacle clearance violations around airports. It was applied for a safety case at Frankfurt Airport where a tower elevating 4 km out of threshold 25R violates severely obstacle limitation surfaces. The model refers to a takeoff and landing performance model (TLPM) computing precisely aircraft trajectories for both standard and engine out conditions at ground proximity forming the model’s reference data: The generated tracks are used to estimate collision risk considering stepwise EASA/FAA, EU-OPS & ICAO clearance criteria. Normal operations are assessed with a probabilistic analysis of empirical takeoff / landing track data generating the local actual navigation performance (ANP) at site. The ANP leads through integration to collision risk with any obstacle. This step passed, the obstacle is tested for clearance within a “5-step-plan” against all performance requirements for landing climb, and takeoff climb. The methodology so delivers a comprehensive risk picture: The presented safety case for Frankfurt Airport showed an equivalent safety level despite the standards violation: The collision risk during both normal and degraded performance operations was found to be still within ICAO CRM limits requiring only limited risk mitigation measures. The presented work should complement ICAO Doc. 9774 Appendix 3.
pdf logo image pdf logo image Integrated Airport/Airside Operations
59 321 Maintaining separation between airliners and RPAS in non-segregated airspace
Author: Enric Pastor , Marc Perez-Batlle, Xavier Prats, Pablo Royo, Raul Cuadrado

abstract

When an airliner and a Remotely Piloted Air System (RPAS) have conflicting courses that may compromise the minimum safety separation between them, how much in advance should the RPAS start the separation maneuver? Which is the optimal heading change that will guarantee the desired separation distance with a minimum reaction time? These same questions can be asked if it is the airliner that performs the separation maneuver. In previous research, the authors showed that in the case the RPAS maneuvers, it has to do it much in advance due to its typical poor flight performance at typical RPAS cruise altitudes. In this paper, we address the safety margins that are left for the RPAS or the airline should any of them execute the separation maneuver. We also investigate if those margins remain safe when the RPAS cannot comply with the required separation maneuver and the airliner needs to initiate that maneuver as a last resort to avoid the conflict. Dealing with an RPAS-airliner conflict opens a new dimension to the safety of the separation maneuver. An RPAS that is commanded to maneuver and initiate a separation maneuver may become all the sudden unresponsive (due to internal failure or due to the feared lost link situation). The paper also assesses the operational point of view by simplifying the reaction times and conflict geometries by grouping them in a small set of cases, regarding the probability of a loss of separation event.
pdf logo image pdf logo image Unmanned Aircraft Systems (UAS) Integration
60 325 En Route Speed Control Methods for Transferring Terminal Delay
Author: James Jones , David Lovell, Michael Ball

abstract

In this paper, we present an approach for transferring delay away from the terminal to the en route phase of flight. We propose a multi-objective integer programming model designed to assign delays to flights well in advance of the terminal. The IP model weights an objective of fuel savings and throughput to assign controlled times of arrival to flights 500 nmi from the airport. A series of trade studies is performed to evaluate our concept. First, the model is tuned by developing a Pareto Frontier to identify weight factors on our objective function. We demonstrate that the model can effectively transfer delay en route. This transfer holds up even with relatively moderate carrier compliance. We go on to demonstrate that this delay transfer yields significant fuel savings benefits on a per flight basis.
pdf logo image pdf logo image Trajectory and Queue Management
61 326 How Airlines Set Scheduled Block Times
Author: Lu Hao , Mark Hansen

abstract

Scheduled block time (SBT) setting is a crucial part in airlines’ scheduling. Interviews with the airline and relevant work in ground transportation have shown that SBT and the historical block time distribution have a close relationship. A better understanding of this relationship is a major goal for the FAA and the airlines because the benefits includes less cost, more efficient operations and better performance in the National Airspace System. This paper investigates this relationship with empirical data and multiple regression models. The historical block time information is aggregated to individual flight level to keep track of the performance of the flight over a time period. The distribution of the flight time for a flight is depicted by the difference between every 10th percentiles. We found that departure delay plays a minor role in setting scheduled block-time, and that SBTs have decreasing sensitivity to historical flight times towards the right tail of the distribution. Airlines tend to act “optimistically” and are willing to experience delays in trade of a shorter SBT. We also include OD pair information in the model and found longer SBT is set for larger airports, as padding for busy traffic. Taking the heterogeneity in the behavior across airlines into consideration, we further decompose the dataset to study specific airlines. The historical flight time distribution has similar effect on SBT for different airlines, and low cost carriers tend to set a shorter SBT than legacy carriers. For legacy carriers, we found that American Airlines values level of service provided the most, whereas United Airlines has a really aggressive behavior to cut SBT. Legacy carriers also set a shorter SBT for flights between their own hubs, to avoid the disruption of early arrivals.
pdf logo image pdf logo image Finance and Policy
62 333 Evaluating Air Carrier Fuel Efficiency and CO2 Emissions in the U.S. Airline Industry
Author: Bo Zou , Mark Hansen, Matthew Elke

abstract

We employ ratio-based, deterministic, and stochastic frontier approaches to investigate fuel efficiency among 15 large jet operators (mainline airlines) in the U.S. Given the hub-and-spoke routing structure and the consequent affiliation between mainline and regional carriers, we consider not only fuel efficiency of individual mainline airlines, but also the joint efficiency of each mainline and its regional subsidiaries, as well as efficiency in transporting passengers from their origins to destinations. We find that: 1) airline fuel consumption is highly correlated with, and largely explained by, the amount of revenue passenger miles and flight departures it produces; 2) depending on the methodology applied, average airline fuel efficiency for the year 2010 is 9-20% less than that of the most efficient carrier, while the least efficient carriers are 25-42% less efficient than the industry leaders; 3) regional carriers have two opposing effects on fuel efficiency of mainline airlines: higher fuel per revenue passenger mile but improved accessibility provision; 4) the net effect of routing circuity on fuel efficiency is small.We employ ratio-based, deterministic, and stochastic frontier approaches to investigate fuel efficiency among 15 large jet operators (mainline airlines) in the U.S. Given the hub-and-spoke routing structure and the consequent affiliation between mainline and regional carriers, we consider not only fuel efficiency of individual mainline airlines, but also the joint efficiency of each mainline and its regional subsidiaries, as well as efficiency in transporting passengers from their origins to destinations. We find that: 1) airline fuel consumption is highly correlated with, and largely explained by, the amount of revenue passenger miles and flight departures it produces; 2) depending on the methodology applied, average airline fuel efficiency for the year 2010 is 9-20% less than that of the most efficient carrier, while
pdf logo image pdf logo image Environment and Energy Efficiency
63 334 Air Traffic Flow Management at Airports: A Unified Optimization Approach
Author: Michael Frankovich , Dimitris Bertsimas

abstract

We present a novel integer optimization approach to optimize in a tractable and unified manner the airport operations optimization problem (AOOP). This includes solving the entirety of key air traffic flow management (ATFM) problems faced at an airport: a) selecting a runway configuration sequence, i.e., determining which runways are open at which times and in which mode they operate; b) assigning flights to runways and determining the sequence in which flights are processed (i.e., when they take off or land); c) determining the gate-holding duration of departures; and d) routing flights to their assigned runway and onwards within the terminal area and the near-terminal airspace. The key contribution of this paper is the modeling of these problems, which until present have been studied in isolation, under a framework which is both unified and tractable. This allows the possibility of obtaining system-optimal solutions in a practical amount of time. Furthermore, the approach is implemented on historic datasets from both Boston Logan International (BOS) and Dallas/Fort Worth (DFW) airports. Computational experience indicates that significant improvements can be achieved from this optimization, and that computational tractability is such that real-world implementation is possible.
pdf logo image pdf logo image ATM Performance Measurement and Management
64 335 Impacts of reporting rules and facility consolidation on recorded operational errors in TRACONs
Author: Michael Seelhorst , Mark Hansen

abstract

This paper focuses on the occurrence of aircraft separation minimum violations as documented in the form of operational errors (OEs) at terminal radar approach control (TRACON) facilities. Poisson regression was used to analyze the daily count of OEs at various facilities. The occurrence of OEs was found to increase approximately with the square of daily traffic at TRACON facilities. At TRACON facilities, where separation violations are not automatically reported, an increase in reporting was seen after a new severity metric was introduced in 2007. It was also found that large, consolidated TRACON facilities tend to behave like a sum of several smaller facilities rather than a single larger facility with respect to the occurrence of OEs vs daily traffic. Weather effects such as visibility and wind were found to influence the occurrence of OEs as well. The model prediction for TRACON facilities is very good for the most severe OE types and very poor for the least severe OE types, indicating many unobserved factors contributing to the reporting of the least severe OE types in the terminal environment.
pdf logo image pdf logo image Safety and Resilience
65 342 Analysis of Conflict Detection Performance for Trajectory-Based Descent Operations
Author: Travis Gaydos , Elida Smith, Bill Liao, Liya Wang

abstract

The evolution of time-based metering introduces greater amounts of Trajectory-Based Operations (TBO) in order to improve meter fix delivery accuracy and flight efficiency. Many TBO concepts have been proposed to yield those benefits; among them is the Three-Dimensional Path Arrival Management (3D PAM) concept of operations. 3D PAM operations are accomplished via ground-based automation that provides speed and path advisories to assist controllers in meeting the meter schedule. On-board capabilities enable pilots to accept and efficiently execute the advisory-based clearance. The result is an increased amount of near-idle thrust descent operations and increased use of closed-loop clearances (with full availability of the speed profile and path for each flight). However, these changes, as beneficial as they are, impact how operations are predicted today by fielded en route medium-term conflict detection support capabilities (i.e., time horizon of 3 to 20 minutes). In order to be effective, the current conflict detection automation must be adapted to best support controllers. This paper describes an analysis completed to determine the performance of fielded en route medium-term conflict detection capabilities given these TBO operations and how it may be better adapted via parameter changes. Results show that parameter changes alone will not provide an acceptable level of conflict detection performance due to a high number of false alerts. While more complex changes, in terms of implementation, are less desirable, they may be needed in order to provide an acceptable level of conflict detection performance, with respect to missed and false alerts, for a 3D PAM operations environment as well as for other TBO concepts of operation.
pdf logo image pdf logo image ATM as a Complex System
66 349 Feasibility of a Networked Air Traffic Infrastructure Validation Environment for Advanced NextGen Concepts
Author: Michael McCormack , Alexander Gibson, Matthew Underwood, Lana Miller, Noah Dennis, James Grisham

abstract

NextGen applications reliant upon aircraft data links such as Automatic Dependent Surveillance-Broadcast promise a sweeping modernization of the national airspace system, but the aviation stakeholder community has not yet established a positive business case for equipage. Full-scale flight tests are necessary to validate ADS-B In applications and solidify message standards; however, such ventures are prohibitively expensive and current standards do not support all proposed applications. The 2012 NASA Aeronautics Academy at Langley Research Center explored the notion of emulating aircraft data links such as ADS-B with commercial in-flight Internet systems and electronic flight bags in order to provide a standards-independent and reduced-cost environment for validating deliverable ADS-B and alternate data link concepts of operations and solidifying ADS-B message standards in full-scale flight tests. By examining certification guidelines, technological requirements, available capabilities, and cost, this study has concluded that a Networked Air Traffic Infrastructure Validation Environment can be feasibly realized with minimum certification requirements, aircraft down time, or major expense by way of Class 2 electronic flight bags, any available in-flight Internet solution, and cloud-computing services.
pdf logo image pdf logo image Air Ground Integrated Concepts
67 350 Statistical prediction of aircraft trajectory: regression methods vs point-mass model
Author: Mohammad Ghasemi Hamed , David Gianazza, M. Serrurier, Nicolas Durand

abstract

Ground-based aircraft trajectory prediction is a critical issue for air traffic management. A safe and efficient prediction is a prerequisite for the implementation of automated tools that detect and solve conflicts between trajectories. Moreover, regarding the safety constraints, it could be more reasonable to predict intervals rather than precise aircraft positions. In this paper, a standard point-mass model and statistical regression method is used to predict the altitude of climbing aircraft. In addition to the standard linear regression model, two common non-linear regression methods, neural networks and Loess are used. A dataset is extracted from two months of radar and meteorological recordings, and several potential explanatory variables are computed for every sampled climb segment. A Principal Component Analysis allows us to reduce the dimensionality of the problems, using only a subset of principal components as input to the regression methods. The prediction models are scored by performing a 10-fold cross-validation. Statistical regression results method appears promising. The experiment part shows that the proposed regression models are much more efficient than the standard point-mass model. The prediction intervals obtained by our methods have the advantage of being more reliable and narrower than those found by point-mass model.
pdf logo image pdf logo image Trajectory and Queue Management

Copyright © ATM Seminar 2017