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Airspace Systems Program Newsletter: Quarter 1, OCT–DEC 2013

QUARTER 1: OCT–DEC 2013

Airspace Systems 

Program Newsletter

National Aeronautics and Space Administration

www.nasa.gov

p4 SFO Stratus Ground Delay

Program Completes Field Trial

p9 DWR Operational Trial Key

Findings
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Airspace Systems Program Newsletter: Quarter 1, OCT–DEC 2013

NASA-US Airways Surface Concept of 

Operations Meeting, October 2012

NASA researchers held a two-day meeting on 

October 2 and 3 with US Airways technical staff 

and ramp operations personnel at Charlotte Douglas International Airport. The discussion concerned 

the joint development of a concept of operations for 

the ramp traffic management decision support tool 

based on NASA’s Spot and Runway Departure Advisor (SARDA) technology. Points of consideration 

specifically included core functions such as the surface 

scheduler and taxi-time predictor, the user interface for 

ramp controllers, including electronic flight strips, and 

the scope of potential human-in-the-loop simulation 

of the tool. The group is targeting completion of an 

initial draft concept of operations document by the end 

of November. NASA and US Airways plan to jointly 

develop a prototype decision support tool and evaluate 

performance and human factors via human-in-the-loop 

simulations at Ames Research Center’s Future Flight 

// Technical/Programmatic Highlights 

Satellite view of Charlotte/Douglas International Airport, NASA World Wind 1.3.5
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Airspace Systems Program Newsletter: Quarter 1, OCT–DEC 2013

Central, a high-fidelity tower simulator. Following 

the technical meeting, the NASA researchers gathered 

operational observation data of both US Airways ramp 

operations and air traffic control tower operations. 

(POC: Yoon Jung)

Langley Team Conducts Software 

Verification Workshop, October 2012

The Formal Methods Research Team at Langley 

Research Center organized and taught a class on software verification during a workshop October 9-12 at 

the National Institute of Aerospace (NIA) in Hampton, 

Va. Course instruction focused on the prototype verification system (PVS) theorem prover, which can be used 

to verify safety statements about software systems. 

Forty-one people attended the workshop in person 

and three participated remotely via online connection. 

The list of attendees included not just those from the 

United States, but also researchers from Colombia, 

Brazil, Canada and the United Kingdom, among 

others. Coursework was organized by Cesar Munoz and 

Anthony Narkawicz, who are members of the formalmethods team in the Safety Critical Avionics Systems 

Branch (SCASB) at NASA Langley. Lectures were 

given by team members, including Ricky Butler, Ben 

Di Vito, Alwyn Goodloe, Jeff Maddalon, Cesar Munoz 

and Anthony Narkawicz. Other presenters included 

Heber Herencia-Zapana of NIA, and Sam Owre of SRI 

International, the main developer of the PVS theorem 

prover. Sam Owre also gave an invited lecture on “PVS 

6.0 and Beyond.”

The workshop was comprehensive in its treatment 

of PVS, including basic topics such as modeling, specification, and verification; intermediate topics such as 

PVS proving for algebra and propositional logic; and 

advanced topics such as computational reflection and 

proof scripting. The attendees expressed high interest 

in the covered subjects and provided positive feedback 

about the class. 

Several participants expressed interest in collaborating 

with SCASB personnel on research of common interest, 

such as formal verification of safety-critical software. 

PVS is a key component of several formal verification 

projects at NASA Langley, including the softwareintensive systems component of the System-wide Safety 

Assurance Technologies (SSAT) project, which is part 

of the Aviation Safety Program, and the separationassurance component of the NexGen Concept and 

Technology Development (CTD) project, which is 

part of the Airspace Systems Program. PVS research 

advancing theorem-proving techniques for complex 

Charlotte-Douglas International Airport.
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Airspace Systems Program Newsletter: Quarter 1, OCT–DEC 2013

safety-critical applications is important to the accomplishment of NASA’s mission. 

(POC: Anthony Narkawicz)

Presentations on CD&R at DASC,

October 2012

Denise Jones presented two Conflict Detection 

and Resolution (CD&R) papers at the 31st Digital 

Avionics Systems Conference (DASC) in Williamsburg, 

Va., held October 14-18. The papers, entitled “Airport 

Traffic Conflict Detection and Resolution Algorithm 

Evaluation” and “SURF IA Conflict Detection and 

Resolution Algorithm Evaluation,” were co-authored 

by Denise Jones, Ryan Chartrand, Sara Wilson and 

Sean Commo of NASA; Sharon Otero of Northrop 

Grumman; and Glover Barker of Science Systems and 

Applications, Inc. The papers described results of a 

fast-time simulation study to evaluate CD&R algorithms for collision avoidance in the terminal 

maneuvering area. 

The NASA and Surface Indications and Alerts 

(SURF IA) algorithms were evaluated for various 

runway, taxiway, and low-altitude air-to-air scenarios, 

various levels of CD&R equipage, and various levels 

of horizontal position accuracy. Study results will be 

incorporated into future NASA research to develop 

technology to improve safety and operations on and 

around the airport during NextGen operations, and 

also support development of industry and government 

standards for conflict detection and resolution under 

RTCA Special Committee (SC) 186 to prevent collisions on the runway. 

Shannon Zelinski received a “best in track” and 

a “best in session” acknowledgement for two papers 

she presented at the DASC gathering. In addition, 

co-author Walt Johnson was recognized for his contributions to another “best in track” paper at DASC. 

A list of papers, including these, can be found at 

http://toc.proceedings.com/16464webtoc.pdf

(POC: Denise Jones)

SFO Stratus Ground Delay Program 

Completes Field Trial, October 2012

The operational field evaluation of a model designed 

to calculate key parameters that are used when planning 

ground delay programs at San Francisco International 

Airport, which began on May 15, was completed on 

October 15. The field trials were conducted at the Federal Aviation Administration (FAA) Air Traffic Control 

System Command Center in Vint Hill, Virginia. The 

dates of the field trial were selected to coincide with 

the period of the year during which the marine stratus 

layer typically affects arrivals into San Francisco International Airport. 

Preliminary findings from the field trials indicate that 

the model was able to reduce the avoidable delay by 

an average of 900 minutes: valued in monetary terms 

at nearly $90,000 per ground-delay event. In November 2013, the FAA is slated to decide if the model 

should be included in their Collaborative Air Traffic 
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Airspace Systems Program Newsletter: Quarter 1, OCT–DEC 2013

Management Technology Work Package 4, which is 

scheduled for operational deployment in 2016. 

(POC: Shon Grabbe)

Simulation Achieves Major Milestone, 

October 2012

The Terminal Area Precision Scheduling and 

Spacing (TAPSS) research group made major strides 

over the past four months, extending the TAPSS system 

to include flight deck interval management capabilities for human-in-the-loop (HITL) evaluation. The 

advanced scheduling capabilities in the TAPSS system were also ported and tested in the FAA’s software 

baseline. To validate the system integration and develop 

the concept of operations, procedures, symbology and 

phraseology, HITL simulations were completed with 

eight controllers and 13 pseudo pilots. The experiment, held October 15-19, investigated controller and 

pilot interactions in a mixed-equipage environment. 

Simulation results will be used to refine the concept of 

operations in preparation for the Air Traffic Management (ATM) Technology Demonstration-1 (ATD-1), 

an operational demonstration of the integrated set of 

advanced time-based scheduling with controller- and 

flight deck-based precision spacing capabilities that 

expedites fuel-efficient arrival operations during periods 

of high throughput. 

(POC Jane Thipphavong) 

Charlotte Airport Operations 

SME Workshop, October 2012

A two-day workshop was held at Ames Research 

Center October 22-23 to discuss surface traffic 

operations at Charlotte-Douglas International Airport (CLT). NASA researchers learned about CLT 

operations in great detail from subject matter experts 

(SMEs), including a retired ATC tower controller, a 

retired traffic management coordinator/supervisor, a 

US Airways ramp controller, and a pilot. The information gathered from the workshop will be used for 

modeling airport operations and designing a ramp 

controller decision support tool based on NASA’s Spot 

and Runway Departure Advisor (SARDA) technology. 

The SMEs provided comprehensive overviews of their 

different roles, responsibilities, and interactions with 

others and also conducted a role-play to illustrate the 

flow of aircraft control from descent to takeoff. NASA 

researchers demonstrated the SARDA tool, and the 

San Francisco, Golden Gate Bridge encased in fog.
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Airspace Systems Program Newsletter: Quarter 1, OCT–DEC 2013

group discussed NASA’s future development of surface 

tools. (POC: Yoon Jung)

Aircraft Self-Separation Experiment Data 

Collection, October 2012

Separation Allocations in Shared Airspace (SALSA) 

data collection was initiated on October 31 for a 

human-in-the-loop experiment, which investigates an 

advanced separation assurance concept for Air Traffic Management—Autonomous Flight Rules (AFR). 

AFR is a NASA Langley-developed airspace operating 

concept in which an aircraft equipped with Automatic 

Dependent Surveillance Broadcast (ADS-B) reception 

capability and a flight deck automation tool is responsible for maintaining separation from other traffic. 

The three-week SALSA simulation experiment, 

conducted in the Langley Air Traffic Operations Lab 

(ATOL), focuses on airline pilot operations under 

AFR, and is a companion experiment to an air-trafficcontroller-based experiment recently completed at the 

NASA Ames Airspace Operations Lab (AOL). In each 

of the three weeks of the Langley experiment, 10 to 

12 airline pilots operated five to six desktop simulators 

equipped with self-separation technology in highdensity simulated NextGen airspace managed by 

three air traffic controllers. 

The challenge addressed in these two coordinated 

experiments, both sponsored by the NASA Airspace 

Systems Program’s NextGen Concepts and Technology Development Project, is the development of a safe 

and operationally acceptable (to pilots and controllers) 

integration in the same airspace of two “function 

allocations” for separation assurance: self-separating 

aircraft and ground-based separation for non-equipped 

aircraft (a.k.a. Instrument Flight Rules (IFR) aircraft). 

The integration rules establish that AFR aircraft are 

burdened to resolve any conflicts that occur with IFR 

aircraft and that air traffic control is not responsible for 

AFR-IFR separation. 

The Langley ATOL experiment tests various conflict 

timings, geometries, and intent-information-sharing 

conditions to determine the performance and pilot 

acceptability of mixed operations from the pilot’s 

perspective. The simulation platform incorporates the 

Autonomous Operations Planner (AOP), a NASA 

Langley-developed prototype flight deck tool for separation assurance. Results of the SALSA experiment 

will be combined with controller-based results from 

the NASA Ames AOL experiment to inform the airspace community on options for introducing new automation capabilities and revised air/ground allocations 

of the separation function in the pursuit of NextGen. 

The potential impact of AFR to operators is a significant increase in operational flexibility and a significant 

decrease in the operating costs associated with ground 

delays and various airspace and operational restrictions 

imposed in today’s airspace operations. In addition, 

if the mixed-operations concept tested in SALSA is 

successful, AFR compatibility with near-to-midterm 

NextGen operations would enable AFR implementation to be accelerated.

(POC: David Wing)
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Airspace Systems Program Newsletter: Quarter 1, OCT–DEC 2013

NASA Offers Support to RTCA SC-186 

WG-4/EuroCAE WG51-Subgroup 3, 

November 2012

 Dr. Bryan Barmore and Mr. Michael Koch attended 

a November 5-8 meeting of the Radio Technical 

Commission for Aeronautics (RTCA) Special Committee 186 (SC-186) and the European Organization 

for Civil Aviation Equipment (EuroCAE) Working 

Group 51 (WG-51) subgroup at the Airbus Company 

in Toulouse, France. SC-186 and WG-51 are developing Flight Deck Interval Management (FIM) and 

Traffic Situation Awareness with Alerts (TSAA) Minimum Operational Performance Standards (MOPS), 

which are new capabilities being introduced as part of 

the FAA’s NextGen Airspace Program. The NextGenSystem Analysis, Integration, and Evaluation (SAIE) 

Air Traffic Management (ATM) Technology Demonstration-1 (ATD-1) activity intends to demonstrate 

MOPS-based FIM procedures, software, and equipment for use in flight trials planned for 2015-2017. 

This meeting was the third in a series of quarterly 

meetings and only included committee members 

supporting the FIM MOPS. Its primary focus was to 

discuss the results and status of several ongoing efforts 

in support of Operational Performance Analysis (OPA) 

and Operational Safety Analysis (OSA) activities. Dr. 

Barmore led the Delta operational services and environment description (OSED) discussion presenting a summary of final operational scenarios and the results of a 

workshop conducted to address several small OSEDrelated questions that rose out of previous meetings. 

Mr. Koch held several breakout meetings with committee leadership and equipment manufacturer representatives to discuss the impacts of new display requirements 

the FIM equipment must support. New display 

requirements have impacted the architecture assumed 

for ATD-1, affecting planned experiments and the 

avionics development already underway. 

The results of the OPA and OSA activities will drive 

many of the MOPS requirements, which will directly 

affect the FIM avionics development for ATD-1. Some 

analyses were mature enough to begin driving requirements. Others are still a work in progress and have not 

yet led to any tangible requirement recommendations. 

The objective of presenting such work was to gain committee buy-in with regard to the analysis approach, or 

to share preliminary results, which must be studied further. Once complete, the MOPS will pave the way for 

FIM to be integrated into commercial aircraft and into 

the national airspace system, contributing to efficiency 

gains in arrival operations and improvement in airport 

throughput and capacity.

The next meeting is scheduled for early March at the 

RTCA Headquarters in Washington D.C. The MOPS 

development is scheduled for completion in May, 2014. 

(POC: Michael Koch)

ATD-1 Field Test Demonstration Kickoff 

Meeting, November 2012

The November 6-7 meeting in Washington D.C. 

included the FAA chief scientist for architecture and 

NextGen development, the ASP deputy program 
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Airspace Systems Program Newsletter: Quarter 1, OCT–DEC 2013

manager, research transition team members from NASA 

research centers Ames and Langley, and multiple FAA 

organizations and projects. The ATD-1 chief engineer 

presented information about ATD-1 and addressed key 

questions regarding field-demonstration constraints, 

FIM equipage, and use of National Air Traffic Controllers Association personnel. The FAA presented detailed 

schedules for Time-based Flow Management (TBFM); 

Surveillance and Broadcast Service (SBS); Terminal 

Automation and Modernization (TAMR); and En 

Route Automation Modernization (ERAM). Each 

showed investment decision points and deployments, 

and the test-NCP process for field-testing prototypes. 

The primary outcome was identifying that the FAA’s 

SBS office is looking at a field test in FY16 that would 

be an opportunity to use NASA FIM designs with the 

FAA equipping a few planes and providing a key site. 

The next step is for the ATD-1 team to draft a field 

demonstration description of what would be included 

to leverage the FAA field test, and to iterate the 

expected benefits of the demonstration. The FAA will 

provide feedback and, from its point of view, describe 

the necessary steps to prepare for and achieve demonstration objectives. 

(POC: Ron Johnson)

ATD-1 Phase 1 Avionics Concept 

Development Report, November 2012

On November 12, Mr. Michael Koch hosted representatives from The Boeing Company who were 

presenting results of a trade study report in support of 

the ATD-1 Phase 1 Avionics Concept Development 

contract. The meeting was well attended. ATD-1, 

sponsored by the SAIE Project within ASP, aims to 

demonstrate the feasibility and value of integrating 

three NASA research efforts intended to achieve high 

throughput, fuel-efficient arrival operations throughout a busy terminal airspace. Two of these efforts are 

focused on ground-based tools for center and terminal 

controllers while the third – FIM – focuses on the 

aircraft avionics and flight crew procedures to conduct 

airborne spacing operations. The heart of FIM operations is the algorithm used to achieve and maintain 

a desired spacing interval. NASA Langley researchers 

have developed a trajectory based algorithm called Airborne Spacing for Terminal Arrival Routes (ASTAR), 

which promises to support Performance-Based Navigation (PBN) requirements and address deficiencies 

found in other approaches. This contract represents the 

first step in a multi-phase effort to develop FIM avionics for the ATD-1 demonstration. It focuses on feasibility and trade studies, simulator and cockpit integration, 

a demonstration, and recommendations. 

The trade study report and associated presentation 

represent the second major deliverable of the contract. 

The report focused on architectural evaluation of the 

integration of the ASTAR algorithm in air transport 

class aircraft during the NextGen midterm 2016-

2020 timeframe. For existing aircraft, such as a 737-

NG, configurations for both forward-fit and retro-fit 
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Airspace Systems Program Newsletter: Quarter 1, OCT–DEC 2013

implementation types were considered. A 787-8 was 

also considered since it is representative of an advanced 

avionics platform from which a NextGen baseline type 

can be formed. A total of 28 architectures arising from 

seven trade variables were evaluated. Rough order-ofmagnitude, non-recurring engineering estimates and 

approximate time-on-task development flow times 

were generated for each. 

Moving forward, the results of the trade study will 

be used to guide ATD-1 FIM avionics development. 

ATD-1 aims to equip multiple aircraft to demonstrate 

in-flight interval management operations in the 2015–

2017 timeframe. The information generated by all 

ATD-1 activities, including this trade study, the avionics development, and the in-flight demonstration, will 

inform the FAA and industry on the FIM concept and 

facilitate NextGen technology transfer into the national 

airspace system.

(POC: Michael Koch)

Presentation of CD&R Algorithm Evaluation 

to RTCA SC-186 SURF IA Committee, 

November 2012

On November 14, Denise Jones presented results of a 

fast-time simulation study to evaluate Enhanced Traffic 

Situation Awareness on the Airport Surface with Indications and Alerts (SURF IA) algorithm to the Radio 

Technical Commission for Aeronautics (RTCA) Special 

Committee 186 (SC-186). This committee developed 

SURF IA requirements to increase flight crew situation 

awareness of the runway environment and facilitate an 

appropriate and timely response to potential conflict 

situations to prevent collisions on the runway. The 

goal of the fast-time study was to evaluate the performance of the SURF IA algorithm under various runway 

conflict scenarios, multiple levels of SURF IA system 

equipage, and various levels of horizontal position 

accuracy. The study uncovered some shortcomings with 

the SURF IA algorithm that the RTCA committee will 

address in further development of the SURF IA industry and government standards.

(POC: Denise Jones)

DWR Operational Trial Key Findings, 

November 2012

The Dynamic Weather Routes (DWR) tool has been 

running nearly continuously – 23 hours a day, seven 

days a week – at the American Airlines (AA) Operations 

Center in Fort Worth, Texas since the operational trial 

began on July 17, 2012. AA users – air traffic control 

Dynamic Weather Routes tool in operation at the 

American Airlines System Operations Center in 

Fort Worth, Texas
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Airspace Systems Program Newsletter: Quarter 1, OCT–DEC 2013

coordinators and flight dispatchers – evaluate time and 

fuel saving routes proposed by DWR, and may also use 

DWR to evaluate reroutes for any of their flights, e.g., 

ones where a route is not proposed. Analysis of 60 days 

of trial data (from July 31 through September 30) comprising about 800 AA flights in Fort Worth Center airspace clearly shows that the DWR search engine, which 

automatically finds more efficient weather-avoidance 

routes, results in five times as many routes rated acceptable by AA users compared with the manually initiated 

search. Users are busy, especially during weather events, 

so it is more effective to let automation find the highvalue reroutes.

 The data show that 38% of DWR routes evaluated 

by AA users were rated as acceptable for a total potential 

savings of 311 flying minutes, with significant potential 

for additional savings. Reroutes totaling over 3,000 minutes of potential savings were left unevaluated mainly 

due to limited staffing during the trial. Assuming that 

the acceptance rates are consistent for unevaluated 

routes, 1,000 more minutes of potential savings could 

be achieved. User feedback has been very favorable and 

some DWR route clearances have been issued to AA 

flights; analysis of actual savings is under way.

(POC: Dave McNally)

NASA Develops Technology To Aid Regional 

Jet Operators, November 2012

NASA engineers met with flight operations personnel from regional jet operator SkyWest Airlines on 

November 15 to discuss recent NASA findings, which 

suggest that SkyWest could save upwards of 50 pounds 

of fuel per regional jet flight by altering arrival procedures to use more optimal flight-path angles that 

would avoid the need to deploy speed brakes. NASA 

has developed an algorithm that can inform operators, such as SkyWest, what flight-path angle would be 

optimal given the prevailing winds, route of flight and 

other factors such as the descent-speed profile being 

advised by the Efficient Descent Advisor (EDA), where 

in use. These savings are above and beyond the fuel and 

environmental benefits provided by EDA, and the new 

algorithm/tool would also reap benefits for un-delayed 

flights (e.g., into low-density “out stations”), essentially 

providing EDA-like benefits without using EDA. The 

SkyWest officials quickly verified that even 20 pounds 

of fuel savings would make an operationally and economically significant difference, since their policy is to 

plan fuel loads down to tens of pounds. They also confirmed the viability of the proposed operational concept 

for the tool. An invention disclosure is being written, 

and planning for a January 2013 technical interchange 

meeting at Ames Research Center is underway. 

(POC: Steve Green)

Initial International Collaborations 

Workshops, December 2012

Dr. Banavar Sridhar, Dr. Yoon Jung, and Mr. Ty 

Hoang attended two workshops in early December 

to kick-off recently signed international collaboration 
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Airspace Systems Program Newsletter: Quarter 1, OCT–DEC 2013

agreements between NASA and the German Aerospace 

Center (Deutschen Zentrums für Luft- und Raumfahrt, DLR) and the National Aerospace Laboratory 

of the Netherlands (Nationaal Lucht en Ruimtevaartlaboratorium, NLR). The first workshop, hosted by 

DLR’s Institute of Flight Guidance in Braunschweig, 

Germany, included participants from DLR research 

centers in Braunschweig, Hamburg, Cologne, and 

Oberpfaffenhofen, who shared their expertise in generating the impact of aviation emissions and contrails as a 

function of space and time. NASA shared its knowledge 

in generating trajectories to minimize environmental 

cost functions. 

Methodologies were discussed for selecting and 

sharing suitable data needed to generate the computationally intensive environmental cost functions, 

and providing details about the traffic and weather 

information exchange needed to cover U.S., European 

and transatlantic airspace. Researchers from the two 

organizations also discussed simulation tools for global 

air traffic, climate impact, trajectory optimization, 

and relevant surface traffic management technologies, 

and refined the already signed three-year collaboration 

agreement. The surface work is intended to create a 

common integrated concept of departure management 

and taxi management on the airport surface, model 

DLR’s time-based taxi scheduler at a U.S. airport, 

integrate with NASA’s surface movement optimization 

algorithm, and perform fast-time simulations using 

NASA’s fast-time surface simulation tool.

The NASA team attended the second workshop at 

NLR to explore a promising collaboration in surface 

conflict detection that complements current NASA 

research efforts in the airport surface domain. The joint 

NASA-NLR effort will focus on testing NLR’s taxiway movement conflict detection technology, with the 

potential to later integrate this technology with NASA’s 

surface movement optimization algorithm.

(POC: Dr. Banavar Sridhar, Dr. Yoon Jung, Ty Hoang)

Runway Configuration Management 

Discussions in Munich, December 2012

In support of the Runway Configuration Management research area of a collaborative agreement 

between the German Aerospace Center (DLR) and 

NASA under the Airspace Systems Program, Gary Lohr 

visited the Munich Airport Tower to gather information regarding the potential implementation of the 

Tactical Runway Configuration Management (TRCM) 

element of the NASA System Oriented Runway Management (SORM) work at an airport in Germany. The 

Munich Airport is the second busiest in Germany based 

on enplanements. 

Mr. Lohr and Nikolai Okuniek (DLR’s lead for the 

runway management collaboration area) were hosted 

by a senior air traffic controller who provided an 

overview of air traffic operations, including procedures, 

constraints and common practices. At a high level, 

International Civil Aviation Organization (ICAO) 

procedures are not significantly different from those 
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Airspace Systems Program Newsletter: Quarter 1, OCT–DEC 2013

used in the United States, but further investigation is 

required to identify procedural differences that would 

potentially affect the suitability of SORM capabilities 

at German airports. Airport Tower personnel shared 

information enthusiastically and were excited that 

NASA was interested in their operation. Collaboration 

between NASA Langley SORM researchers and DLR 

will continue to advance the state of air traffic efficiency 

in their respective airspace systems. 

Capabilities developed by DLR focus on efficiency 

for arrival, departure, and surface air traffic operations; 

however, they assume a static runway configuration. 

The TRCM capability provides runway configuration 

and usage recommendations that will complement these 

capabilities, thereby improving overall efficiency and 

minimizing disruption during configuration changes. 

(POC: Gary Lohr) 

Yearlong Traffic-Management Study Results Published, December 2012

Results of a yearlong study were recently published in 

Volume 20 (2012) Number 4 of the Air Traffic Control 

Quarterly journal. The study examined the potential 

impact of controlling Hartsfield Jackson Atlanta International Airport arrivals using a new control strategy 

that is referred to as a Traffic Management Advisor 

Flow Program. This new capability reduces the demand 

for a capacity-limited airport by assigning pre-departure 

delays to flights bound for the airport. 

With the help of traffic flow managers at the FAA’s 

Air Traffic Control System Command Center, operationally viable scenarios were developed that were 

subsequently explored by NASA researchers through 

fast-time simulations. The emphasis of the study was 

on examining the distribution of delays and emissions 

for flights included and exempt from this new capability. Among the key findings from this study: as the 

rate of the Traffic Management Advisor Flow Program 

was increased from 54 aircraft per hour to 80 aircraft 

per hour, the fuel burn and emissions associated with 

airborne holding was found to increase by over 100%. 

Although this increase in fuel burn and emissions, in 

general, represents a small percent of the total fuel burn 

and emissions associated with the entire flight’s trajectory, it does illustrate the importance of considering the 

delays as well as the emissions associated with future 

traffic flow management control strategies. 

The study can be read in its entirety at: http://www.

aviationsystemsdivision.arc.nasa.gov/publications/2012/

ATCQ_20-3-203_Grabbe.pdf

(POC: Shon Grabbe)
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