Airspace Concept Evaluation System- State of Development POC: Kee Palopo Kee.Palopo@nasa

1. Airspace Concept Evaluation System- State of Development POC: Kee Palopo Kee.Palopo@nasa.gov 10 December 2008

2. Outline • Process • Requirements • Development • ACES 6.0 (Near-term Capabilities) • Studies Using ACES • Planned ACES Development

3. Requirements Process • Project Driven (milestones and principal investigators) • Review • Branch and Division • Start with Research Question • Experiment Plan • Meetings • Workshops and Conferences • Request For Proposals

4. Development Phases Build N Build N+1 Requirements* One Year FAA, Glenn, JPDO, Langley, Others Main Build *includes enhancement and maintenance

5. ACES 6.0 • Communication, Navigation, and Surveillance (CNS) models with uncertainty • Advanced Airspace Concept (AAC) • Pre-computed schedule of sector capacities • Dynamic Sub-sector Assignment • Swappable Trajectory Generator • Traffic Management Advisor • ACES-FACET

6. Studies Using ACES • S. Karahan, S. Zelinski, “Creating Convective Weather Scenarios for Simulating Weather Reroutes,” AIAA Modeling and Simulation Technologies Conference and Exhibit,” AIAA 2007-6557 Hilton Head, South Carolina Aug. 20-23, 2007 • R. Windhorst, H. Erzberger, “Fast-Time Simulation of an Automated Conflict Detection and Resolution Concept,” 6th AIAA Aviation Technology, Integration and Operations Conference (ATIO), Wichita, Kansas, Sept. 25-27, 2006

7. Studies Using ACES (cont’d) • S. Zelinski, L. Meyn, “Validating the Airspace Concept Evaluation System for Different Weather Days,” AIAA Modeling and Simulation Technologies Conference and Exhibit, Keystone, Colorado, Aug. 21-24, 2006 • K. Palopo, R. Windhorst, B. Musaffar, M. Refai, “Economic and Safety Impacts of Flight Routing in the National Airspace System,” 7th AIAA ATIO Conference, Belfast, Northern Ireland, Sept. 18-20, 2007

8. Studies Using ACES (cont’d) • G. Chatterji, Y. Zheng, “Impact of Airport Capacity Constraints on National Airspace System Delays,” 7th AIAA ATIO Conference, Belfast, Northern Ireland, Sep. 18-20, 2007 • S. Sahlman, “Description and Analysis of a High Fidelity Airspace Model for the Airspace Concept Evaluation System,” AIAA Modeling and Simulation Technologies Conference and Exhibit, Hilton Head, South Carolina, Aug. 20-23, 2007

9. Ongoing Studies Using ACES • Nation-wide Separation Assurance using AAC • Single-center NAS-wide • 42K flights 24 hours • 25 hours on one high-end Mac • Wind-Optimal Study • Annual basis • 1X traffic • 4 hours on 7 Linux machines • Plot by airlines

10. Conflicts Types and Resolution Order • Auto resolver is designed to resolve three types of conflicts: • Loss of separation conflicts • Weather conflicts • Arrival sequencing conflicts • An aircraft may be involved with all three types at the same time Source: Dr. Heinz Erzberger

11. Conflicts Types and Resolution Order (cont’d) • Auto resolver resolves conflicts in the following sequence: • Weather conflicts • Arrival sequencing conflicts • Loss of separation conflicts

12. Flow Chart for Algorithm Input Conflict Pair Formulas and logic for calculating simplified resolution traj. Resolution Maneuver Generator 4D Trajectory Synthesizer Heavy duty numerical calculations Traj. completed? No Yes Check traj. for conflicts Conflicts detected ? Yes No Res. Traj. accepted

13. Resolution Process Current list of conflicts Updated at regular intervals Pick next conflict for resolution Priority based on time to first loss Generates multiple resolutions for each aircraft; special rules for weather conflicts Resolution algorithm Continue this loop until all conflicts are resolved Weather conflict? Yes No Secondary conflict? Yes No Update flight plan Current flight plan is replaced with resolution flight plan Execute resolution

14. AAC Remarks • An algorithm that generates resolution trajectories for the full spectrum of possible conflicts has been designed • Simultaneously resolves conflicts with convective weather, loss of separation conflicts and sequencing conflicts. • Algorithm comprises a mix of rule-based procedures and analytical formulas. • ACES has proven to be a valuable tool for development and analysis of algorithm

15. AAC Remarks (cont’d) • Real time controller and pilot interactive simulations have demonstrated high degree of controller and pilot acceptance at up to 3x traffic levels. • Web-based documentation of software has been developed to assist in technology transfer to users

16. Another Separation Assurance Study • Trajectory prediction uncertainties for AAC: • Aircraft weight • Descent profile • Wind uncertainty • Maneuver initiation delays • Aircraft-based AAC • Multi-center AAC Source: Dr. Todd Lauderdale

17. Trajectory Prediction Uncertainties • Can introduce uncertainties into the trajectory used for conflict prediction • Uncertainties can be controlled and understood Predicted Actual Actual Predicted

18. Aircraft-Based AAC • Each aircraft is aware of all aircraft in the sensor range ‘r’ • Each aircraft uses AAC to resolve conflicts of which they are aware r

19. Aircraft-based AAC Unresolved Conflicts

20. Aircraft-based AAC Time to First Loss

21. Aircraft-based AAC- Run Time

22. Multi-Center AAC • AAC can run in multiple centers simultaneously • A buffer of control and visibility can be established around each center ZOB AAC ZID AAC ZDC AAC

23. Planned ACES Development • Integrate enhanced terminal model TME/STLE into ACES 7-11 • Port and Enhance Weather Agent • Enhance Traffic Flow Management (TFM) • Other Model Enhancements • Metric Enhancements (Dynamic Density, Complexity, and AAC)

24. Planned ACES Development (cont’d) • Miscellaneous Supporting Tools • Terminal Area and Airport Surface Editor • ACES Viewer Development with Air Force Research Laboratory • ACES Toolbox Enhancements

25. STLE Surface Modeling

26. Automated Terminal Area Node-link Generator

27. Example TAASE Editor View

28. Enhanced Terminal Modeling • Airport Air Traffic Control • Model 4D Traffic Movement on Surface • Determine runway takeoffs/landing and gate entries/exits • Airport TFM – Generate TFM Landing Restrictions • TRACON TFM – Propagate Arrival Fix Crossing Restrictions

29. Enhanced Terminal Modeling (cont’d) • TRACON Air Traffic Control • Model 4D Traffic Movement through Terminal Airspace • Determine Airport Landing/Departure Fix Crossings • Flight – 4D Trajectory for Terminal/En Route Airspace

30. Airport Air Traffic Control • Surface 4D route/re-route planning with/without Required Time of Arrivals • Surface 4D route/re-route and clearance limit assignment • Surface domain representation: Gate, Ramp, Taxiway, Runway • Gate assignment and occupancy management • Ramp and Taxiway intersection transit control with gridlock resolution

31. Airport Air Traffic Control (cont’d) • Takeoff runway assignment • Runway takeoff/landing/taxi crossing transit control • Surface transit Required Time of Arrival conformance monitoring/alerting • Surface traffic state monitoring/alerting

32. Airport Air Traffic Control (cont’d) • Autonomous flight movement with aircraft in-trail self-separation • Acceleration/Deceleration • Nominal Roll/Stochastic speed assignment subject to speed limit

33. Airport Traffic Flow Management • Gate assignment and occupancy time prediction • Runway assignment prediction • Surface 4D route prediction with/without Required Time of Arrivals • Traffic Flow Management Runway takeoff/landing planning • Takeoff-time Traffic Flow Management Restriction generation

34. Airport ATC/TFM Utilities • Gate selector • Runway selector • Surface prescribed route assigner • Surface shortest path calculator • Air Traffic Control Runway takeoff/landing planner

35. TRACON Air Traffic Control • Terminal airspace 4D route/re-route planning with/without Required Time of Arrivals • Terminal airspace 4D route/re-route and clearance limit assignment • Landing runway assignment • Airspace fix transit control • Airspace transit Required Time of Arrivals conformance monitoring/alerting • Airspace traffic state monitoring/alerting

36. TRACON Traffic Flow Management • Terminal airspace 4D route prediction with/without Required Time of Arrivals • Arrival/Departure fix crossing planning • Airports operating conditions forecasting • Airports runway configuration planning • Arrival fix crossing-time Traffic Flow Management Restriction propagation

37. MPAS Improvements • Make stable at aircraft minimum speed • Model short flights and low-altitude tower en route flights • Integrate Flight Management System generated vertical trajectories to meet restrictions • Support holding patterns • Pluggable

38. Flight Management System • Generate vertical trajectories from route, time, speed, and altitude restrictions • Model vertical profiles for jet, turboprop, and piston aircraft • Interface with surface movement model at the runway threshold • Pluggable

39. Concluding Remarks • Requirements are gathered from project investigators and researchers and incorporated into development • Studies go on in parallel • ACES is in active development at one-year cycles • Main trunk • Branches of parallel development