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Airspace Systems Program Newsletter: Quarter 1, OCT–DEC 2011

QUARTER 1: OCT–DEC 2011

Airspace Systems 

Program Newsletter

National Aeronautics and Space Administration

www.nasa.gov

p2 Efficient Descent Advisor 

Achieves Technology Transfer

p10 NASA/FAA Collaborative 

Research to Improve Tactical 

Departure Scheduling
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Airspace Systems Program Newsletter: Quarter 1, OCT–DEC 2011

Efficient Descent Advisor Achieves 

Technology Transfer

The Efficient Descent Advisor (EDA) was transferred 

to the FAA on November 30, 2011, culminating a 

three-year collaborative effort between NASA, FAA, 

Boeing and airline partners to develop and transition automation for efficient arrival operations during 

capacity-constrained conditions. Launched under a 

Research Transition Team (RTT) in 2008 that later 

became known as the 3D-Path Arrival Management 

(3D-PAM) activity, EDA was developed as a decisionsupport tool for sector controllers in the Air-Route 

Traffic Control Center (ARTCC). The automation was 

developed for deployment in the 2014–2018 timeframe, in support of mid-term NextGen operations.

// Technical/Programmatic Highlights 

Figure 2: A picture of a controller’s computer screen during the simulation shows how the Efficient Descent Advisor indicates 

cruise speed, descent speed and path components.

Figure 1: This graph shows the different advisories generated by 3D-PAM involving a combination of cruise-speed 

and descent-speed (top), and descent-speed and routing 

adjustments (bottom).
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Airspace Systems Program Newsletter: Quarter 1, OCT–DEC 2011

Concept: EDA leverages core elements of NASA’s 

Center-TRACON Automation System (CTAS) to 

develop strategic arrival solutions over time horizons 

of up to 30 minutes. Solutions are sought that allow 

aircraft to perform fuel-efficient, continuous descents at 

low engine power while satisfying time-based-metering 

constraints at the TRACON boundary computed by 

the Traffic-Management Advisor (TMA) – a previous CTAS tool that is now deployed at all 20 ARTCC 

facilities in the United States. Whenever possible, 

EDA computes trajectory solutions that are predicted 

to be conflict free in order to minimize interruptions 

to an otherwise continuous descent. Once computed, 

EDA’s trajectory solutions are decomposed into specific maneuver advisories, which are presented to the 

radar-side sector controller upon request. In the final 

prototype delivered under 3D-PAM, advisories involve 

a combination of cruise-speed, descent-speed and 

routing adjustments, as depicted in Figure 1. Although 

EDA is designed to deliver aircraft to the TRACON 

boundary, it facilitates continuous descents to the runway by reducing the need for unnecessary delay absorption within TRACON airspace. 

Figure 2 illustrates a controller’s use of EDA in a 

Human-in-the-Loop (HITL) simulation conducted in 

support of 3D-PAM. In this example, a controller has 

clicked on the EDA portal for a flight near the center 

of the display. The EDA portal is located at the bottom of the aircraft’s flight-data block. Once a portal is 

clicked, a separate window opens on the controller’s 

Figure 3: Two air traffic controllers use Efficient Descent Advisor during the simulation in the Crew-Vehicle Research 

Facility at NASA’s Ames Research Center.
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Airspace Systems Program Newsletter: Quarter 1, OCT–DEC 2011

display containing the advisory information. The 

trial-plan route associated with this advisory is also 

displayed, which includes the location of the aircraft’s 

predicted top-of-descent point (not visible in Figure 2 

due to scale). EDA advisories become available once 

aircraft have crossed an arc where the TMA scheduled 

time-of-arrival has been frozen. This arc, known as the 

freeze horizon, is typically 20 minutes or more from 

the TRACON-boundary meter fix, adjustable for traffic and airspace conditions within the TMA system. 

Once aircraft have crossed the freeze horizon, controllers are alerted to the availability of EDA advisories by 

blue-colored EDA portals. In the example shown in 

Figure 2, the EDA advisory consists of cruise speed, 

descent speed, and path components. Path advisories 

are typically issued whenever advised slow downs are 

insufficient for absorbing the delay needed to meet 

TMA-scheduled times. EDA ensures that path-stretch 

maneuvers do not cross lateral sector boundaries in 

order to minimize controller workload associated with 

inter-sector coordination. 

The format, phraseology and procedures associated with EDA advisories and clearance delivery were 

designed to be compatible with current air-traffic operations and flight-deck equipage. Once received on the 

flight deck, pilots enter EDA clearances directly into 

the Flight Management System (FMS) for precision 

guidance and control along the intended trajectory. As 

the aircraft progresses along the trajectory, EDA continuously monitors conformance to the scheduled arrival 

time at the meter fix and provides controllers with corrective advisories if necessary. 

Research Approach: Technology transfer of EDA 

was based primarily on the iterative design and development of a research prototype, validated using HITL 

simulation (Figure 3). For added fidelity, these simulations included trajectory-prediction uncertainty, modeled using results from two flight tests conducted at 

Denver Center in which revenue flights operated by 

United, Continental and Skywest were issued predefined EDA speed clearances. These flight tests also 

involved an FAA aircraft – a Global 5000 business 

jet – that was issued a combination of speed and path 

clearances (Figure 4). 

Seven HITL simulations were conducted in the 

NASA Ames Crew-Vehicle Research Facility (CVSRF). 

Figure 4: The flight deck crew of FAA’s Global 5000 prep 

for flight tests to model trajectory-prediction uncertainty.
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Airspace Systems Program Newsletter: Quarter 1, OCT–DEC 2011

These simulations involved controllers from the Denver ARTCC, with later simulations including controllers representing the National Air Traffic Controllers 

Association. While NASA focused on ground-based 

automation and procedures, Boeing focused on airborne 

automation and procedures by running separate experiments in their Seattle laboratories as part of the joint 

3D-PAM activity. 

Research Findings and Deliverables: The majority of the HITL simulations were intended to facilitate 

prototype development by comparing various design 

alternatives. For example, simulation #3 evaluated the 

use of intermediate altitude for arrival-time conformance and conflict resolution. Although altitude advisories were effective in resolving conflicts, the workload 

and procedures required for implementing them proved 

Figure 5: This graph shows how adding Efficient Descent Advisor’s capabilities to the Traffic Management Advisor improved 

the aircraft’s arrival time accuracy and precision. 
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Airspace Systems Program Newsletter: Quarter 1, OCT–DEC 2011

impractical for controllers. Other design studies looked 

at variations on path-stretch anchor points and the use 

of EDA during all traffic conditions as opposed to only 

when demand exceeds capacity. Controllers favored the 

use of EDA during all traffic conditions because of the 

consistent procedures that it afforded and the knowledge of arrival intent that it provided. In simulation #5, 

the use of conflict-probe automation alongside EDA 

was evaluated to aid in the detection and resolution of 

conflicts up to 25 minutes away. Results showed that 

controllers benefited from strategic conflict probe automation in terms of both performance and workload. 

The final HITL simulation, completed in September 

2011, examined the benefits of EDA compared to baseline operations with TMA alone. The final simulation 

also included airline pilots who flew the Boeing 747 

and 737 cockpit simulators at the CVSRF. This was 

the first simulation to make use of the new B737 model 

installed in the CVSRF’s Advanced Concepts Flight 

Simulator. Results showed substantial improvement 

in arrival-time accuracy and precision at the meter 

fix with EDA, as shown by the error histogram in 

Figure 5. Results also showed a 100% reduction in 

number of manual sequence adjustments required by 

the controller for managing traffic with EDA, which 

suggests further capacity benefits through the preservation of the sequence assigned by TMA for optimal 

runway throughput. Preliminary results also indicate a 

reduction in controller workload and fuel consumption 

with EDA. The average number of maneuver-related 

arrival clearances issued per flight was reduced by 60% 

with EDA. A reduction in maneuver clearances can be 

Figure 6: This graph shows that Efficient Descent Advisor reduced the average number of maneuver-related arrival 

clearances per flight by 60 percent.
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Airspace Systems Program Newsletter: Quarter 1, OCT–DEC 2011

seen in Figure 6, which shows how controllers managed 

arrival traffic with fewer tactical altitude instructions 

with EDA. A reduction in altitude assignments also 

contributed to an estimated fuel savings of 180 lbs per 

flight with EDA averaged across all aircraft types in the 

busier of the two traffic scenarios evaluated. 

The findings from each simulation and field-test 

activity were delivered in reports to the FAA. NASA 

also delivered a detailed specification of the final EDA 

prototype design. This deliverable served as the foundation for the transfer of EDA technology to the FAA and 

the culmination of the government/industry 3D-PAM 

activity launched by the RTT in 2008.

Next Steps: The FAA Air Traffic System Concept 

Development Group, which led the 3D-PAM activity, 

is currently engaging the FAA’s service-level organizations in discussions pertaining to EDA deployment. In particular, planning is underway to address 

a requirement for new ground-based automation in 

2014, stemming from the FAA’s Trajectory-Based Flow 

Management Office. This office is interested in deploying EDA technology to extend the capabilities of the 

current TMA system in support of NextGen. 

(POC: Rich Coppenbarger)

Wakenet USA Meeting, October 2011 

Neil O’Connor, Ed Johnson, Nash’at Ahmad, Randy 

Vanvalkenburg, and Fred Proctor attended the Wakenet 

USA meeting at the United Airlines Flight Training 

Center in Denver. Don Delisi, David Lai, and Matt 

Pruis from Northwest Research Associates also attended 

under the sponsorship of a NASA NRA contract. 

Approximately 70 people attended the meeting representing government agencies, airlines, airframe manufactures, industry, academia, and international agencies. 

Subject areas included mid- and long- term wake solutions for aircraft spacings, Recategorization of Aircraft 

Spacings (RECAT), enroute wake recognition and 

mitigation, the details of an agreement for the FAA to 

obtain in-flight wake data from the National Research 

Laboratory (Canada), and a briefing of the aviation 

safety reporting system for wake encounters. 

(POC: Neil O’Connor)

At the EDA technology transfer ceremony, (left to right) 

Dr. Jaiwon Shin, NASA ARMD associate administrator; 

Victoria Cox, assistant administrator for Next Gen, FAA; 

and David Grizzle, chief operating officer, FAA’s Air 

Traffic Organization. 
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Airspace Systems Program Newsletter: Quarter 1, OCT–DEC 2011

Presentations from the NASA team at this 

workshop included:

1. Proctor, F.H., 2011: Transport and Decay of Wake 

Vortices under the Influence of Crosswind Shear. 

Wakenet USA, 18-19 October, Denver, Colo., Powerpoint Presentation, 18pp.

2. Pruis, M., and D. Delisi, 2011: Update on the NASA 

Probabilistic Model. Wakenet USA, 18-19 October, 

Denver, Colo., Powerpoint Presentation, 17pp.

3. Johnson, E., and C. Lunsford, 2011: Progress in 

Including Aircraft Meteorology Data in ADS-B 

Message Sets. Wakenet USA, 18-19 October, Denver, Colo., Powerpoint Presentation, 13pp.

4. Lai, D., 2011: A Lidar Simulator Tool for Vortex 

Measurements. Wakenet USA, 18-19 October, Denver, Colo., Powerpoint Presentation, 17pp.

5. O’Connor, N., and D. Delisi, 2011: New NASA 

Research Announcement for Wake. Wakenet USA, 

18-19 October, Denver, Colo., Powerpoint Presentation, 12pp.

NASA Researchers Awarded Session Best 

Papers at 30th DASC, October 2011 

“Integration of Weather Avoidance and Traffic Separation,” a paper by Maria Consiglio, Jim Chamberlain, 

and Sara Wilson, won the Best Paper of the session 

award from the ATM Efficiency Track at the Digital Avionics Systems Conference (DASC). Jim Chamberlain 

presented the paper which was based on the Weather 

Integration and Scheduling Performance (WISP) Study. 

The paper describes a dynamic convective weather 

avoidance concept that compensates for weather motion 

uncertainties, the integration of this weather avoidance 

concept into a prototype 4-D trajectory-based Airborne 

Separation Assurance System (ASAS) application, and 

test results from a batch (non-piloted) simulation of the 

integrated application with high traffic densities and a 

dynamic convective weather model. 

The weather model can simulate a number of pseudorandom hazardous weather patterns, such as slow- or 

fast-moving cells and opening or closing weather gaps, 

and also allows for modeling of onboard weather 

radar limitations in range and azimuth. The weather 

avoidance concept employs nested “core” and “avoid” 

polygons around convective weather cells, and the simulations assess the effectiveness of various avoid polygon sizes in the presence of different weather patterns, 

using traffic scenarios representing approximately two 

times the current traffic density in en-route airspace. 

Results from the simulation experiment show that the 

weather avoidance concept is effective over a wide range 

of weather patterns and cell speeds. Avoid polygons that 

are only 2-3 miles larger than their core polygons are 

sufficient to account for weather uncertainties in almost 

all cases, and traffic separation performance does not 

appear to degrade with the addition of weather polygon 

avoidance. Additional “lessons learned” from the batch 

simulation study are discussed in the paper, along with 

insights for improving the weather avoidance concept. 

The paper can be found at: http://ntrs.nasa.gov/archive/

nasa/casi.ntrs.nasa.gov/20110020261_2011018011.pdf
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Airspace Systems Program Newsletter: Quarter 1, OCT–DEC 2011

“Effects of Scheduling and Spacing Tools on Controller’s Performance and Perceptions of their Workload,” authored by Lynne Martin, Harry Swenson, 

Alex Sadovsky, Jane Thipphavong, Liang Chen and 

Anthony Seo, was awarded Best Paper in session within 

the Human Factors Track. The paper documented 

recent Terminal Area Precision Spacing and Scheduling (TAPSS) system human-in-the-loop simulation 

experiments and the positive system performance and 

workload benefits. The TAPSS system research has been 

focused on investigating potential benefits for NextGen 

mid-term operations and forms the basis for the Airspace Technology Demonstration-1. The paper can be 

found at http://www.aviationsystemsdivision.arc.nasa.gov/

publications/2011/DASC2011_Martin.pdf

Additional participation included Will Johnson chairing the Software Applications session in the Avionics 

Design track and presentation of nine other papers by 

researchers from the Airspace Systems Program in areas 

of Air Traffic Management research. 

(POC: Sandy Lozito)

Boeing 737-800W Model Integrated with 

Advanced Concepts Flight Simulator, 

October 2011

The Simulation Laboratories (SimLabs) recently 

completed a successful integration of the Boeing 737-

800W airframe model with the Advanced Concepts 

Flight Simulator (ACFS). Both were then utilized for 

the seventh and final simulation of EDA. To facilitate 

The B747-400 Simulator at NASA’s Ames Research Center. 
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Airspace Systems Program Newsletter: Quarter 1, OCT–DEC 2011

the accurate descent trajectories required for the simulation, the Boeing 737 autopilot functionality was 

implemented and integrated with the simulator’s GE 

Aviation simulated Flight Management System (sFMS). 

The high-fidelity engine and fuel-burn models available with the 737 and 747 simulation models allowed 

comparison of the fuel used during descent, with and 

without EDA. The initial integration and testing of the 

B737-800W model on the ACFS was funded by an 

American Recovery and Reinvestment Act task order. 

(POC: Bimal Aponso)

Successful Test of En Route Trajectory 

Automation Integrated with FANS-1/A 

and En Route Automation Modernization, 

October 2011 

Two-way air/ground data-link communication 

(data comm) using today’s actual data comm network 

(ARINC) and actual Boeing 777 flight hardware was 

demonstrated using NASA ground-based trajectory 

automation from the Center/TRACON Automation System (CTAS) at Ames, and a B777 simulator 

equipped with integrated Flight Management System 

(FMS)/data comm at Boeing in Seattle, Wash. The 

Boeing “Gateway” application enabled a variety of 

route and altitude messages anticipated to be typical in 

future NextGen data comm operations, such as log-on 

and log-off needed to establish and discontinue data 

comm, route and altitude uplink and downlink messages and their associated wilco and/or unable messages, and downlink of aircraft flight plan intent and 

FMS trajectory intent data. The work completes an 

FY10/11 American Reinvestment and Recovery Act task 

to prototype the integration of NASA ground-based 

trajectory automation with today’s integrated FMS/data 

comm and the FAA’s En Route Automation Modernization (ERAM) system. Similar testing in August 2011 

at Lockheed-Martin (Rockville, Md.) demonstrated 

two-way communication between CTAS and ERAM. 

Lockheed and Boeing together have proposed to NASA 

that this integrated CTAS/data comm/ERAM system be 

the basis for operational trials of trajectory-based automation with data comm in the FY13/14 time frame. 

(POC: Dave McNally)

SOSS Released, October 2011

The Surface Operations Simulator and Scheduler 

(SOSS), a fast-time surface modeling and simulation 

software developed by NASA, was released to a 

This screen shot captures the controller display from the 

Trajectory-Based Automation System. 
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Airspace Systems Program Newsletter: Quarter 1, OCT–DEC 2011

private organization for the first time since the 

software was created. The SOSS source code and 

associated documents were released to Saab Sensis, 

which is using the software for modeling airports and 

conducting benefit assessments of the surface functions developed by NASA. Future plans include wider 

release of the software.

(POC: Yoon Jung)

NASA/FAA Collaborative Research to 

Improve Tactical Departure Scheduling, 

October and November 2011

Development, evaluation, and transition of the Precision Departure Release Capability (PDRC) continued 

with a new NASA Research Announcement (NRA) 

contract and further collaboration with the FAA. At 

an NRA contract kickoff meeting held October 21st, 

This graphic shows the PDRC field test observation positions in the vicinity of DFW airport.
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Airspace Systems Program Newsletter: Quarter 1, OCT–DEC 2011

Mosaic ATM, Inc. presented plans to enhance and 

extend the PDRC concept, collect quantitative PDRC 

benefits data via operational evaluations, and support 

transition of NASA-developed PDRC technology to 

the FAA. In a separate but related event on October 

25th, FAA headquarters stakeholders visited the NASA/

FAA North Texas Research Station to assess the maturity of the PDRC concept and discuss how best to 

transfer PDRC technology for implementation in the 

National Airspace System. NASA presented recently 

published results and provided a live-traffic demonstration of the PDRC system. During the follow-on meeting in November the FAA recipients for this NASA 

technology and the specific transfer deliverables were 

identified. An overview of the PDRC field evaluation 

in July was also discussed, and plans were presented for 

how to proceed with possible follow-on field evaluations and development of the transition deliverables. 

(POC: Shawn Engelland)

Assessment of Environmental Impacts Due 

to Air Traffic, October 2011 

A research team led by Metron Aviation, which 

includes the Logistics Management Institute and Purdue University, presented their plans to continue NASA 

supported research to assess environmental impacts. 

SEACAT (System-level Environmental Assessment of 

Concepts and Technologies) will refine the estimates 

of the effects of new ATM technologies and perform 

a more extensive analysis of how each technology 

contributes to the trades between environmental 

impacts, enabling more projected throughput, and 

reducing delay. SEACAT is also exploring the potential 

benefits of alternative fuels and reducing greenhouse gas 

impact of aviation. The team presented results on CO2 

emissions and noise results based on simulation runs. 

During the meeting, NASA provided feedback and the 

SEACAT team presented their research plans and deliverables for the year. 

(POC: Neil Chen)

System Oriented Runway Management 

Quarterly Review, November 2011

The 10th quarterly review of the three-year contract 

supporting System Oriented Runway Management 

(SORM) research focused on the work of expanding 

the SORM algorithms to consider Runway Configuration Management (RCM) for multiple airports where 

there are dependencies based on physical proximity 

or flight paths (i.e. metroplexes). Mosaic ATM, Inc., 

the principal investigator, and team members LMI, 

AVMet, and College of William & Mary presented: 

(1) results from initial testing of a metroplex RCM 

algorithm; (2) progress on the New York metroplex 

modeling and simulation; (3) LMI’s work on studying 

whether or not including environmental factors will be 

important for SORM airport configuration decisions; 

(4) AvMet’s work on the relationship between weather 

events and airport configuration decisions; and (5) the 

College of William and Mary’s work on an alternative 
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Airspace Systems Program Newsletter: Quarter 1, OCT–DEC 2011

mathematical technique for more quickly solving the 

tactical RCM problem. The review concluded with a 

discussion of plans for completing the current contract 

and new topics such as an integrated NASA simulation 

incorporating SORM with air-traffic-management tools 

being developed at Ames. 

(POC: Gary Lohr) 

Prototype of Improved Terminal Area 

Scheduling Model, November 2011 

An initial prototype of the Event-Based Stochastic 

Simulation of Terminal Airspace OpeRations (ESSTOR) has been completed. This new simulation is an 

extension of the Stochastic Terminal Area Scheduling 

Simulation (STASS), which has been used for fasttime simulations to investigate aircraft arrival concepts. 

ESSTOR is event based, which will eventually enable 

the simulation of multiple, concurrent schedulers. It 

currently models the FAA’s Traffic Management Advisor 

scheduler with greater fidelity than the previous STASS 

simulation. An effort is currently underway to develop 

input data sets from recorded TMA data. 

(POC: Larry Meyn)

FAA Conflict Resolution Advisory 

Simulation, November 2011

NASA was invited to participate in the FAA’s humanin-the-loop experiment devoted to conflict resolution 

automation. The technical interchange provided a rare 

opportunity for NASA to interact with a variety of 

separation assurance researchers and FAA research managers. NASA’s representative was provided a detailed 

look at FAA’s technology and development plans for 

conflict resolution automation, and NASA was afforded 

an opportunity to share information about its latest 

technology, plans, and recent simulation results. By 

engaging with the FAA at this early stage, NASA is 

seeking to foster a collaborative relationship with the 

FAA on conflict resolution technology for the future, 

and that goal was achieved. NASA has been invited to 

attend the next FAA activity, a large-scale human-inthe-loop experiment scheduled for March 2012. 

(POC: Confesor Santiago) 

FAA Attends T-SAFE Discussions, 

November 2011

FAA members of the Minimum Safe Altitude Warning/Conflict Alert (MSAW/CA) Safety Board visited 

NASA Ames to learn how NASA-developed Terminal-Tactical Separation Assured Flight Environment 

(T-TSAFE) could resolve problems seen with the legacy 

tactical conflict detection tool, Conflict Alert (CA). 

The FAA briefed NASA on current problems with 

CA, which includes late and false alerts causing controllers to become desensitized to the tool and ignore 

it. T-TSAFE (adapted from en-route TSAFE) uses 

flight intent information to improve loss-of-separation 

prediction and significantly reduce false alerts. NASA 

researchers briefed the FAA on the initial evaluation of T-TSAFE algorithms in a human-in-the-loop 
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Airspace Systems Program Newsletter: Quarter 1, OCT–DEC 2011

simulation. NASA also briefed the FAA on an analytical comparison of CA with a newly improved 

severity-based T-TSAFE, which has the potential to 

address difficulties associated with mixed Instrument 

and Visual flight separation rules. The FAA invited 

NASA researchers to deliver briefings at the next official 

MSAW/CA Safety Board meeting to be held at NASA 

Ames Research Center on February 7-9, 2012. 

(POC: Shannon Zelinski) 

NASA Updates RTMA, November 2011

In cooperation with the FAA, NASA updated its modifiable research version of the FAA’s operational Traffic 

Management Advisor called the Research Traffic Management Advisor (RTMA). RTMA is directly derived 

from the Traffic Management Advisor software currently 

deployed across the United States for time-based arrival 

metering and tactical departure scheduling. RTMA 

includes modifications needed to build and run in a 

Linux research environment, without the monitor and 

control infrastructure found in the deployed software. 

RTMA currently supports many NASA research activities including PDRC and the FAA terminal metering 

research at Dallas Love Field. By using a platform similar to the FAA’s most current version of the operational 

TMA, air traffic research concepts and technologies 

developed using RTMA will be more easily transferred 

to the FAA for field-testing and deployment. 

(POC: Shawn Engelland)

Community Interest Follows Release of 

Autonomous Flight Rules (AFR) Concept 

Definition, November 2011

An Autonomous Flight Rules (AFR) Concept has 

been proposed as a new set of operating regulations in 

which aircraft navigate on tracks of their choice while 

self-separating from traffic and weather. AFR would 

exist alongside Instrument and Visual Flight Rules (IFR 

and VFR) as one of three available flight options for 

any appropriately trained and qualified operator with 

the necessary certified equipment. Historically, groundbased separation services evolved by necessity as aircraft 

began operating in the clouds and were unable to see 

each other. Today, technologies for global navigation, 

airborne surveillance, and on-board computing enable 

the functions of traffic conflict management to be fully 

integrated with navigation procedures on-board the 

aircraft. By self-separating, aircraft can operate with 

more flexibility and fewer restrictions than are required 

when using ground-based separation. The AFR concept, described in detail in NASA/TP-2011-217174, 

provides practical means by which self-separating 

aircraft can share the same airspace as IFR and VFR 

aircraft without disrupting the ongoing processes of Air 

Traffic Control. The AFR Technical Paper has generated genuine community interest both in the concept 

itself and in NASA’s air traffic management research. 

Multiple requests for the paper have been received, 

including a request from the JPDO Trajectory Based 
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Airspace Systems Program Newsletter: Quarter 1, OCT–DEC 2011

Operations (TBO) Study Team. The paper can be 

found at: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.

gov/20110023668_2011023330.pdf

(POC: David Wing)

SARDA Benefit Assessments, 

December 2011

To further the surface functions developed by NASA, 

Saab Sensis Corp was selected to perform a systematic 

benefit assessment of the Spot and Runway Departure 

Advisor (SARDA) tool at three airports. After extensive surveys and criteria development, John F. Kennedy 

International Airport, Boston Logan International 

Airport, and Charlotte Douglas International 

Airport were selected. Next steps include modeling 

the selected airports, evaluating the performance of 

NASA-developed surface schedulers emulated from the 

SARDA tool, and applying them to the airports. These 

activities will support the April 2012 human-in-theloop simulation and future collaboration with an industry partner for a potential field evaluation of a decision 

support tool for airline, tower and ramp operators.

(POC: Yoon Jung) 

Second Aviation Climate Change 

Research Initiative (ACCRI) Symposium, 

December 12-15, 2011 

The symposium, sponsored by the FAA Office of 

Environment and Energy, focused on the modeling of 

chemistry climate impacts of aviation, contrails and 

metrics. NASA’s Banavar Sridhar presented a paper on 

the integration of simple climate models, contrails and 

metrics with air traffic simulation in the United States. 

The simulation was used to develop route optimization 

methods and to study the impact of cross-polar traffic 

on emissions. The paper, which provided context to 

the topics discussed in the symposium, was very well 

received and cited as an example of interdisciplinary 

research. It was suggested that the route optimization 

methodology could be used to reduce the exposure to 

cosmic radiation during polar flights. During the symposium, Banavar met with Ulrich Schumann (DLR), 

Pat Minnis (LaRC) and John Murray (LaRC). The 

topics discussed included route optimization with 

environmental impacts, convective weather/volcanic 

ash and wake vortex research. These topics are a continuation of ongoing conversations between NASA 

Headquarters and DLR. Both sides have complementary information to contribute including the air traffic 

simulation and optimization work at NASA, and DLR 

expertise in the modeling of contrails and their project, Reducing Emissions from Aviation by Changing 

Trajectories for the benefit of Climate (REACT4C). 

The proposed visit of DLR scientist Volker Grewe to 

NASA’s Ames Research Center during the summer of 

2012 should provide an opportunity to enhance the 

NASA/DLR collaboration. 

(POC: Banavar Sridhar)
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Airspace Systems Program Newsletter: Quarter 1, OCT–DEC 2011

Researchers Achieve Significant Improvement in Climb Trajectory Prediction with 

Actual Flight Track Data, December 2011

A new algorithmic technique developed by NASA 

researchers has reduced climb-trajectory prediction 

errors by about 15% in evaluations with actual host 

radar track data. Aircraft climb trajectories are arguably the most difficult to project; large errors in these 

predictions increase the rate of false and missed alerts 

from separation assurance automation and reduce the 

potential operational benefits of some advanced concepts for NextGen. The algorithm improves climbtrajectory prediction accuracy by dynamically adjusting 

the aircraft weight modeled for trajectory predictions 

based on observed track data. This past fall, researchers 

implemented this adaptive climb-trajectory prediction 

algorithm in CTAS, NASA’s real-time ground-based 

research system. Initial tuning of the algorithm was 

conducted using Fort Worth Center air traffic data from 

the week of November 28. Then, the algorithm was 

evaluated using air traffic data in the same Center from 

the following week. Results indicate the algorithm was 

able to reduce the altitude error by 6-25% (or roughly 

80-220 feet). Future work will include stress testing the 

algorithm over a wider range of traffic and environmental conditions, including high wind uncertainty, low and 

high wind shear, etc. Additional enhancements to the 

algorithm may also include the development of logic 

to infer aircraft climb profile characteristics, including 

capture speeds. 

(POC: David Thipphavong)

Air Traffic Collaborations with the State of 

Alaska, December 2011 

Alaska’s deputy commissioner of the Aviation Division, along with the project manager for the Statewide 

Mapping Initiative from the Alaska Department of 

Transportation, conducted a follow-up visit to NASA 

regarding collaborations related to air traffic management. Three proposals were presented by NASA, to 

which the Alaska officials provided feedback and next 

steps to further solidify the collaborations. One proposal, the Traffic and Atmospheric Information for 

General Aviation (TAIGA) Android-based tool, would 

display weather, air traffic management, and terrain data 

on a smartphone device. The aircraft’s position would 

be updated using built-in GPS technology within the 

smartphone. A second proposal would provide weather 

mitigation strategies to minimize the impact of fog or 

other visibility constraints for Anchorage arrivals. This 

proposal will use the NASA-developed Future Air traffic management Concepts Evaluation Tool (FACET) 

combined with Anchorage weather forecasts and strategic scheduling algorithms. The third proposal would 

provide state-of-the-art conflict alert capability to the 

Anchorage TRACON using NASA’s Terminal Tactical 
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Airspace Systems Program Newsletter: Quarter 1, OCT–DEC 2011

Separation Assured Flight Environment (T-TSAFE) 

technology. The airspace around Anchorage is complex 

and, in addition to the Ted Stevens International Airport, includes within ten miles of each other a seaplane 

‘seaport,’ a busy air force base (Elmendorf AFB), and a 

general aviation airport (Merrill Field).

(POCs: Shon Grabbe, Joey Rios)
National Aeronautics and Space Administration

Headquarters

300 E. Street, SW

Washington, DC 20024

www.aeronautics.nasa.gov

www.nasa.gov