DM 4/4/02

Direct-To Controller Tool

FAA/NASA Joint University Program MeetingNASA Ames Research Center

April 4-5, 2002

Dave McNallyDirect-To Project Lead

Automation Concepts Branch

Heinz ErzbergerSenior Scientist

Aviation Systems Division

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Origins• Under current day operations aircraft generally fly on fixed routes and

en route Center radar controllers have very limited automation to help them work traffic more efficiently.

• Potential of a Direct-To Tool was discovered unexpectedly during field tests of CTAS Conflict Probe / Trial Planning functions at Denver Center (Sept. 97) and was confirmed at Fort Worth Center (Nov. 98)

• At both centers, controllers pointed out a preferred use for the Trial Planning function: Searching for and evaluating direct routes that are conflict free.

• The Direct-To Tool was built to automate the search for and execution of direct route trajectories.

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Direct-To (D2) Features

• Radar controller tool for analysis and input of route and altitude options

• Advisories for traffic conflicts and time-saving (wind-favorable) direct routes

• Trial Planner analyzes traffic conflicts, wind effect on flying time, preferential routing restrictions, special use airspace

• Rapid feedback software design and sparse information display well suited to radar controller

• Based on CTAS trajectory analysis methodology and software. One additional module connected to CTAS TMA system

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D2 Route Advisories

Direct-To identifies aircraft that can save at least one minute by flying direct to a down-stream fix on their route of flight.

Route advisories are displayed in the flight data block (FDB) and an optional list on the controller’s traffic display The Trial Planner allows controllers to easily

display, modify, and input Direct-To flight plan amendments to the Host computer.

Potential savings in flying time for Ft. Worth Center airspace is approximately 1,800 minutes per day or about 2.5 minutes per Direct-To clearance advisory.

N797FA > 6

330 C215 390

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D2 Routing Algorithm

DFW.DALL5.TXK ..LIT.J131.PXV.J29.JHW.J82.ALB.GDM2.BOSMSP./.TUL.J87.BILEE.CUGAR6.IAH

Examples:

Boundaries of Limit Rectangle1000 x 800 nm

800

nm

1000 nm

.TORNN

Direct-To RoutesFlight Plan Routes

..CUGAR

IAH

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Trial Planner• Click D2 advisory

(list or FDB) to activate Trial Planner

• Trial Plan status updates every 1 sec– Graphic display

– Traffic Conflicts

– Pref. Routings

– Time Savings

– Special Use Airspace

• Click fix menu to modify route

• Click “Accept” to amend flight plan

Direct-To Display

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Auxiliary Waypoints

• Click and drag anywhere on

trial plan route to add auxiliary

waypoint

• Wind-corrected magnetic

heading to the waypoint

appears in flight data block

• Waypoint automatically added

to flight plan amendment

message

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Conflict Probe• Probabilistic analysis of CTAS

trajectories (12 sec update)

• Flight data block or list-based alerting

on traffic display

• Click for graphic display

• Direct route advisories automatically

probed for conflict

• Expanded separation criteria for route

advisories and trial planning (12 mi,

4000 ft for transitioning a/c)

• Conflict status updates every 1 sec

while in trial planning

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Automatic Altitude Probe

Altitude Trial Planner automatically conflict probes climb or descent to any altitude

Climb Example

FL330

FL310

290280

270260

250240

230220

210

AAL123 BOS230T 207B767 380

AAL123Accept330C310C290C280C270C260R250R240C230RCancel

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Direct-ToOperational Testing

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Field Test Operations

• 3 high altitude sectors, Fort Worth Center, May 21 - June 14, 2001.

• 9 member controller team

• D-Side controller operated Direct-To Tool

• 4 weeks, 4 days/week, 136 sector-hours

• 3204 trial plans, 1198 flight plan amendments

Direct-To Display

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Trial Planner Usage - Monitor Alert Period

Sector 86 Monitor Alert = 13 aircraft

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Direct-To Usage vs. Traffic Count

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Obsolete Weather Avoidance Routes

• Severe weather affected aircraft routing during 8 of 16 field test days

• Direct-To identified several routes where weather no longer a factor

• Controller team pointed out that without D2, routing opportunity may have gone unnoticed due to route truncation on paper strips

• 27 aircraft routed direct, 253 min total savings, 9.4 min average savings

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A

BTM - minimum time to fly

TD2

TB

TFPNet D2 Savings

Max

imum

Bas

elin

eP

oten

tial

Flying Time Savings Model

Time Savings

Flying Time

D2

Fie

ld T

est

TFP - time to fly on flight plan

TB - baseline time to fly (no tool)TD2 - time to fly with D2 aiding

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Texarkana/PXV - DAL204

Average Net D2 Savings = 0.96 Minutes

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Normalized Net D2 Savings

Net D2 SavingsS =

Potential Savings

AAL1614

DAL204

All 86/HRV

All 90/PXV

S No. FieldTest Flts.

No. Base-line Flts.

4 6

6 5

18 27

25 51

66%

59%

51%

35%

Net D2 Savings

Max

imum

Bas

elin

eP

oten

tial

Time Savings

D2

Fie

ld T

est

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Conclusions• Direct-To is suitable for the R-Side traffic situation

display and will provide substantial benefit to the R-Side controller.

• Direct-To facilitates a net savings in flying time for aircraft operating in Fort Worth Center.– 1 minute on common routes– 5 minutes or more on obsolete weather avoidance routes– 50% of facility-wide potential savings

• Direct-To and TMA can run on a common CTAS system under operational conditions.

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Current Research

• Merge D2 with operational radar displays (DSR R-Side)

• Develop methods for integration of D2 with Traffic Flow Management and arrival metering

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References

www.ctas.arc.nasa.gov

Publications

UPR Papers

Direct-To Papers

POC: Dave McNallydmcnally@arc.nasa.gov

(650) 604-5440