1. Presented to: NAS-Wide Simulation & NextGen workshop By: Kimberly Noonan, Joseph Post Date: December 10th, 2008 Federal Aviation Administration The Modernized NASPAC Simulation Environment

2. Federal Aviation Administration 2 The Modernized NASPAC Simulation Environment 10 December 2008 Your Father’s NASPAC The FAA’s standard system-wide model Originally developed in late 1980s Represents NAS as network of interconnected queues –Airports –TRACONs –En route sectors Discrete-event –SIMSCRIPT II.5 –Fortran, C, Pascal pre-processors Sun Solaris platform Used mainly for investment analysis (i.e., cost-benefit analysis) National Airspace System Performance Analysis Capability

3. Federal Aviation Administration 3 The Modernized NASPAC Simulation Environment 10 December 2008 Legacy NASPAC Environment TAF = Terminal Area Forecast OAG = Official Airline Guide ETMS = Enhanced Traffic Management System OAG TAF Trajectory Builder Fix Inserter 4D Trajectories Sector Crossings Sector Entry/Exit Times Core Queuing Model Output Trace Files Sector Capacities Airport Capacities Sector Geometries Future Demand Generator ETMS Routes Flow Restrictions Itinerary Purge ETMS

4. Federal Aviation Administration 4 The Modernized NASPAC Simulation Environment 10 December 2008 Objectives of Modernized NASPAC Make available to more analysts and projects Maintain fast run time Incorporate traditional trajectory module with fuel burn computation Automate airport weather scheduler Obtain modern, configuration-controlled, documented source code Produce standard, analyst-friendly, repeatable output Validate Develop GUI and output visualization tools Facilitate Monte Carlo simulation

5. Federal Aviation Administration 5 The Modernized NASPAC Simulation Environment 10 December 2008 Modernized NASPAC Environment Wx = weather TAF = Terminal Area Forecast MAP = Monitor Alert Parameter ETMS = Enhanced Traffic Management System Pareto Curves MAP Values Wx ETMS Flight Table Airport Table Sector Table TAF Fleet Evolution Unconstrained Traj.-Based Forecast (2D) Constrained Traj.-Based Forecast (2D) Java Trajectory Module 4D Trajectories Sector Crossings Sector Entry/Exit Times Core Queuing Model Delay Wx Sector Capacities Airport Capacities Unsatisfied Demand Capacity Scheduler Legacy NASPAC Future Schedule Generato r Flow Restrictions Output Parser Itinerary Generation Industry/ Regulatory Response Wind Field Sector Geometries Fuel Burn Rate Δ Fuel Burn Flight Delays Fleet Forecast

6. Federal Aviation Administration 6 The Modernized NASPAC Simulation Environment 10 December 2008 Future Traffic Generation Airport A Airport B Airport C Airport D 2007 ETMS TAF Airport A Airport B Airport C Airport D 2010 Forecast FAA airport forecasts are unconstrained –Yield excessive and unrealistic future delays at some airports Estimated airport capacities used to constrain traffic growth –Mimic operator and FAA response to large demand and capacity imbalances –Apply both schedule smoothing and trimming at 110 airports

7. Federal Aviation Administration 7 The Modernized NASPAC Simulation Environment 10 December 2008 Itinerary Generation Constrained schedule consists of ETMS flight legs –No tail numbers Create aircraft itineraries –Link flight legs with same airline and aircraft type –Minimize total fleet size, i.e. number of itineraries –Respect schedule turn time constraints Min schedule turn time Flight Leg arriving ATL ATL Flight Leg Departing ATL A C B

8. Federal Aviation Administration 8 The Modernized NASPAC Simulation Environment 10 December 2008 Fleet Evolution Retire and replace aircraft with newer types –minimize changes across seat-class/engine-type categories Consistent with APO and Mitre Fleet Forecast Domestic passenger and cargo airlines only

9. Federal Aviation Administration 9 The Modernized NASPAC Simulation Environment 10 December 2008 Java Trajectory Module Aircraft performance –BADA 3.6 tables Waypoints / cruise alt. –ETMS flight plan Arrival/departure fixes –Assigned to flight path Wind data –NCEP/NCAR Global Reanalysis Model 4D track points computed at 1 min. intervals

10. Federal Aviation Administration 10 The Modernized NASPAC Simulation Environment 10 December 2008 Airspace Modeled 939 airspace elements

11. Federal Aviation Administration 11 The Modernized NASPAC Simulation Environment 10 December 2008 OEP Airports Other Airports Airports Modeled All IFR flights touching U.S. airspace are modeled Arrival/departure capacities for 110 airports included –All other airports assumed to have infinite capacity VFR flights at 73 airports included Washington Dulles International Airport Capacities

12. Federal Aviation Administration 12 The Modernized NASPAC Simulation Environment 10 December 2008 Output Files Airport Capacity File (airportc) ATO-P Input Schedule pre-configuration File Sector Capacity File (sector_sim) sim-configuration File Arrival Trace File(t_arr) Arrivals-Departures at Sink Trace File(t_snk) At-Gate Trace File(t_agt) Change Parameter File (change_apt) Cross Arrival Fix-Departure Fix-Restriction Trace File(t_cnd) Departure Trace File(t_dep) Enter-Exit Sector Trace File(t_sec) IFR Trajectories(traject) JTM Bad Flights File JTM Flight Map File JTM Fuel Usage File JTM Generate Itineraries Schedule Pushback Trace File(t_pbk) Flight File Airport File Sector File Oracle Database Perl Script s Input Files Output Files

13. Federal Aviation Administration 13 The Modernized NASPAC Simulation Environment 10 December 2008 Metrics Flights accommodated –Flight trimming process Delay –Gate push-back –Departure runway/fix queuing –Sector queuing –Arrival fix/runway queuing Fuel Burn –Origin to Destination –US airspace CO 2 –Jet A savings converted to CO 2 using multiplier of 21.095 lb/gal

14. Federal Aviation Administration 14 The Modernized NASPAC Simulation Environment 10 December 2008 NASPAC Project Wiki

15. Federal Aviation Administration 15 The Modernized NASPAC Simulation Environment 10 December 2008 Validation Process Run simulation for eight historical days –Demand variation Two days per season (1 weekend, 1 weekday) –Weather variation Actual weather used for each day Distribution of surface and en route weather Compute flight time, delay, fuel burn metrics Compare validation metrics to observed system response –Ground Truth ≡ ASPM, ASQP, BTS databases –Mean, variance –Pooled, pair-wise statistics Every new software release validated!

16. Federal Aviation Administration 16 The Modernized NASPAC Simulation Environment 10 December 2008 Airborne Delay, Daily Observations v5d

17. Federal Aviation Administration 17 The Modernized NASPAC Simulation Environment 10 December 2008 Airborne Delay, OEP Airports 19 Oct. 2006 v5d ORD FLL

18. Federal Aviation Administration 18 The Modernized NASPAC Simulation Environment 10 December 2008 Taxi-Out Delay, Daily Observations v5d

19. Federal Aviation Administration 19 The Modernized NASPAC Simulation Environment 10 December 2008 Push-Back Delay v5d

20. Federal Aviation Administration 20 The Modernized NASPAC Simulation Environment 10 December 2008 ETE Distributions, 19 Oct. 2006 v5d

21. Federal Aviation Administration 21 The Modernized NASPAC Simulation Environment 10 December 2008 Airport Arrival Rate, 19 Oct. 2006 Charlotte-Douglas International Airport v5d

22. Federal Aviation Administration 22 The Modernized NASPAC Simulation Environment 10 December 2008 Fuel Burn 2.8% diff.

23. Federal Aviation Administration 23 The Modernized NASPAC Simulation Environment 10 December 2008 Conclusions Modernized model runs much faster, accessible to more users, and easier to use Deterministic trajectory model provides easy means of specifying flight trajectories –Uses standard Eurocontrol BADA data –Fuel burn computation integrated into trajectory model –Accommodates wind field –Achieves good accuracy in nominal flight time and fuel burn Airborne delays close to observed values Surface delays appear underestimated

24. Federal Aviation Administration 24 The Modernized NASPAC Simulation Environment 10 December 2008 Next Steps Evolve International carrier fleet Enhance airport capacity model –Incorporate additional airport pareto curves based on alternative configurations and/or wind conditions Improve taxi-out delay –Update departure fix en trail constraints Incorporate Traffic Flow Management (TFM) –Ground Delay Programs Include Monte Carlo simulation capability Validation, validation, validation

25. Federal Aviation Administration 25 The Modernized NASPAC Simulation Environment 10 December 2008 Questions?