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Conflict Prediction, Trial Planning and the Direct-To Tool

elements of the

Center/TRACON Automation System

Dave McNallyNASA Ames Research Center

Conflict Probe Technical Interchange MeetingMemphis, Tennessee, October 19-21, 1999

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Background• Airspace users lose $2.8 billion per year due to

inefficient routing. Air Transport Association estimate

• Air Traffic Management Problem:

• Separation

• Metering and Scheduling

• User Preference

• NASA is developing technology to aid controllers with separation and metering and increase user preferred trajectories.

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Transition Airspace

DFW Airport

Arrival Meter Fix

DFW Arrivals

DFW Departures

Overflights in Cruise

flight planroutes

En Route Sector Boundaries

TRACON Boundary

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Conflict Probe and Trial Planner

• CTAS Trajectory Synthesizer (12 sec update)– Radar tracks and flight plans (FAA Host)

– Wind forecast - 1 hour updates (NOAA Rapid Update Cycle)

– Aircraft performance models (FMS quality)

• Conflict Probe (6 sec update)– All aircraft trajectories compared for conflict

– Graphic display of conflict predictions (20 min. look ahead)

• Trial Planner (1 sec update)– Point and click, rapid update, ODID-like “what-if” checking for:

direct, vector, altitude, speed changes

– Trial plan trajectories conflict probed against all other trajectories

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Conflict Probe

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Trial Planner

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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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Traffic Management Advisor

• Computes an efficient arrival sequence that balances arrival demand with airport capacity

• Displays sequence and schedule advisories to help controllers achieve efficient arrival flow

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Trial Planner, TMA, Conflict Probe Integration

390 OK370 OK350 C330 C310 OK

Cancel

NWA732Accept

ACID STA DLY TP DLYDAL456 1439 2AAL629 1437 2 0

TMA METER LIST

NWA732 IHS350B757 390AAL629

&

&

AAL629 020 7350MD80 41001 00 NWA732

Meter Fix

DAL456 DFW350B767 41002 02

&CONFLICT PREDICTION

AAL629 -- NWA732 13 0 2

CONFLICT PAIRS TIME FL NM

TRIAL CONFLICTS

CONFLICT PAIRS TIME FL NM

AAL629 -- NWA732 13 0 15

TMA meteringinformation

Trial plan's effect on conflictand metering status shownsimultaneously

Predicted top-of-descent point

Click for altitudetrial planning

Click and drag forvector trial planning

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Trial Planner, TMA, Conflict Probe Integration

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Denver Center Field TestSeptember, 1997

• Operational evaluation of CTAS Conflict Prediction and Trial Planning capability

• Controllers consistently used Trial Planner for direct route conflict resolution clearances– Ease of use: point and click, menu-

based, graphic display

– Confirm direct route is conflict-free

• Observed 225 % increase in direct routes with CPTP aiding vs. without

Shadow Testing - 10 hours

Operational Testing - 88 hours

3 sectors, 15 test controllers

132 CPTP-aided clearances

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Fort Worth Center Field TestNovember, 1998

Shadow Testing - 54 hours

3 sectors, 6 test controllers

176 accepted Trial Plans

• Operational evaluation of Trial Planner in transition airspace

• Trial planner used as often for non-conflict aircraft as for conflict aircraft.

• Altitude dominant for conflict resolution

– Departures often in conflict– Easy to use altitude trial

planner

• Direct route checking dominant for non-conflict cases

– Mostly DFW departures

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Results Summary

• Trial Planner very well accepted for strategic planning of over-flight and departure aircraft– Controllers preferred use: search for and evaluate conflict-free direct

routes– Observed 225% increase in direct routing with TP vs without.

• Altitude trial planning with automatic altitude probe well accepted

• Additional automation needed for metered arrivals– No time to click and drag for arrival metering problem

• Controller usage of Trial Planner helps identify further automation– Automatic altitude probe, direct route clearance advisories

Trial Planner, TMA, Conflict Probe Integration

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Direct-To Controller Tool

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Origins• 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 Tool• Direct-To identifies

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

• A Direct-To list on the controller’s display shows eligible aircraft, time savings, direct-to fixes, and conflict status.

• The point-and-click Trial Planner allows controllers to easily display, modify, or accept Direct-To flight plan amendments.

• Potential savings in flying time for Ft. Worth Center airspace is approximately 1,800 minutes per day or about 2.5 minutes per aircraft.

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Trial Planning a Direct-To Advisory

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DFW.DALL5.TXK ..LIT.J131.PXV.J29.JHW.J82.ALB.GDM2.BOS

SJC./.TXO..SJT.CUGAR6.IAH

Examples:

Limit Rectangle

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Technical Questions

• Identify operational envelop for use of Direct-To clearance advisories

• Identify sectors or airspace regions where Direct-To could be most beneficial

• Validate fully integrated (CTAS/Host/DSR) Direct-To system

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Trial Planner

A D-Side Operations Concept• Direct-To list filtered by sector ownership displayed on D-Side monitor.

• Controller clicks list element to activate Trial Planner with graphic display. Graphic display closes when Direct-To accepted or rejected.

• Consistent with multiple display windows on D-side (like URET A/C list and GPD)

Direct-To List

DSR R-Side DSR D-Side

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An R-Side Operations Concept

Trial Planner Graphics

Trial Planner Panel

DSR R-Side DSR D-Side

Direct-To List

• Direct-To list filtered by sector ownership displayed on R-Side monitor

• Controller clicks list to activate Trial Planner functions on R-side monitor • R and/or D controllers operate Direct-To

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Recent Activities

• Controller Simulation, NASA Ames, Aug-99– 4 FPL controllers from Fort Worth Center - feedback very favorable

– D controller operated tool and suggested clearances to R controller

– Controller team felt Direct-To ready for field test at Ft. Worth Center

• Host Integration Testing, FAATC, Jun-99– Functional demo of CTAS TMA/Direct-To with 2-way Host interface

– Validated 2 mouse click Direct-To flight plan amendment

– Required only minor mod’s to Host interface (320 patch).

– 250 Direct-To flight plan amendments of various types input to Host

• DSR Integration Testing, Lockheed Martin, Apr-99– Functional demo of CTAS display on D-side monitor with DSR

keyboard, trackball, and network - no perceived delays.

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Direct-To Summary• Using the CTAS Trajectory Synthesis methodology and software with its hourly

wind updates the Direct-To Tool identifies and advises direct route clearances that can save at least 1 minute flying time.

• Direct-To advisories account for arrival routing restrictions (e.g., STARs), do not deviate aircraft significantly from their planned route of flight, and are probed for conflict.

• Lab analysis of live Ft. Worth Center traffic data shows potential for 1,800 min savings per day (2.5 min per clearance avg.) at Ft. Worth Center. This equates to $18,000,000 per year. (NAS-wide estimates are over $100,000,000 per year).

• Controller workload for direct route flight plan amendments is significantly reduced through integration with the Trial Planner: 20+ keyboard entries are reduced to 2 mouse clicks.

• Feedback from controllers and airline representatives is very favorable.

• Fort Worth Center controller team says Direct-To Tool and concept ready for initial field test evaluation.

• Next Steps: DSR simulation at FAATC and field test at Fort Worth Center.

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www.ctas.arc.nasa.govMcNally, D., Bach, R., Chan, W.: “Field Test Evaluation of the CTAS Conflict Prediction and Trial Planning Capability”, AIAA Guidance, Navigation, and Control Conference, August 10-12, 1998, Boston, MA (AIAA-98-4480).

McNally, D., Erzberger, H., Bach, R., Chan, W.: “A Controller Tool for Transition Airspace”, AIAA Guidance, Navigation and Control Conference, August 9-11, 1999, Portland, OR (AIAA-99-4298).

Erzberger, H., McNally, D., Foster, M.: “Direct-To Tool for En Route Controllers”, ATM99: IEEE Workshop on Advanced Technologies and their Impact on Air Traffic Management in the 21st Century. September 26-30, 1999, Capri, Italy.