1. Federal Aviation Administration Managing Arrival Congestion “Rushing to Wait Vs. Slowing to Save (Fuel)” Dave Knorr – FAA Liaison to DFS and Eurocontrol PRU CANSO Benchmarking and Environmental WG‘s

2. 2 Federal Aviation Administration Outline Part 1: Background and Motivation Part 2: Calculated Baseline Inefficiency Part 3: Estimating Terminal time and fuel savings from Speed reduction in Cruise Many Thanks to Co-authors: Philippe Enaud, Xing Chen, Marc Rose, Holger Hegendorfer and John Gulding

3. 3 Federal Aviation Administration Motivation Examples of Controlled Times of Arrival (CTA’s) to manage terminal area congestion: –ALOFT and MAESTRO Programs at Airservices Australia –Collaborative Flow Management – Airways NZ –NATS/United Trials into Heathrow –ATTILA with Delta into Atlanta –Morning Rush into Zurich –FAA ATTILA Trials at Charlotte –Tailored Arrivals into LAX and SFO –UPS use of ADS-B at Memphis –XMAN for FABEC…. And Lufthansa ASCAPE trials –Others?? All cases motivated by fuel savings associated with incorporating FMS capabilities

4. 4 Federal Aviation Administration Excerpt From Air Services Australia on ALOFT

5. 5 Federal Aviation Administration Improvement Pools for Time and Fuel Savings Estimated Benefit Pool Actionable by ANSPs Estimated Average Time (per flight) Estimated Fuel Burn Taxi ~5 min~80 Kg* Cruise~3 min~150 Kg Approach (100nm and in)~3 min~120 Kg Averages for Busiest 34 airports in the US and Europe *Under Review

6. 6 Federal Aviation Administration Consider…. In the US and Europe congestion management is applied based on projected arrival times …… but mainly implemented through ground holds

7. 7 Federal Aviation Administration Consider…. Most flights receiving a ground delay will speed up (fly faster than cost index 0) after receiving a ground delay Premise for discussion: Once an arrival time constraint is established - FUEL is the only variable left for an airline to optimize (after safety)

8. 8 Federal Aviation Administration Additional time within the last 100NM Top 68 Busiest Airports average 3 min of delay and 120Kg additional fuel on approach

9. 9 Federal Aviation Administration Congestion versus Flight Time

10. 10 Federal Aviation Administration Excerpt From NATS Presentation

11. 11 Federal Aviation Administration US and Europe - Establishing a Baseline How much time and fuel is currently spent absorbing delay on approach? Methodologies –Sample Airline data –Statistically based excess time using radar data, ac type and crossing times –Converting excess distance and level segments to time and fuel Reduces impact of wind on estimates…

12. 12 Federal Aviation Administration En-route Flight efficiency Taxi-Out efficiency Efficiency 40 NM Taxi-In Efficiency Gate-to-Gate Efficiency 100NM Efficiency 100NM Inefficiency: Excess time in the last 100NM 100 nmi 40 nmi x Arrival Airport Arrival Fix Actual Route Notional Optimal Route 2.5% Direction of Flight Originally Based on TAER Methodology – ATM2009 Updated to Better Account for Vertical Level-Offs – ATM2011

13. Federal Aviation Administration 50 Flights Active within 15 Minutes A100 Measure Jan 15, 2009 12:30-12:45pm 8 Arrivals in 15 Minutes 8.4 Minutes Average Inefficiency 40 nm 100 nm

14. 14 Federal Aviation Administration Inefficiency Detected from RADAR Data Level Segments Vertical Inefficiency Direct Flight Horizontal Inefficiency = ATC Constraints Fuel (Act(x) – Fuel (Opt(x) Fuel (Opt(x) – Fuel (Opt(x 0 )

15. 15 Federal Aviation Administration Vertical Component d i – distance of level seg. h i – altitude of level seg. h c – new altitude of level segment Change in Time Change in Fuel v(h) – Speed at Alt h f(h) – Fuelburn at Alt h From BADA

16. 16 Federal Aviation Administration Horizontal Component - Cruise Altitude- Actual Distancexx0x0 - Minimum Distance Nominal Speed at Cruise Nominal Fuel at Cruise From BADA v* benchmark speed from 100 nm to 40 nm for the group

17. 17 Federal Aviation Administration Vertical Profile View NWA 1176 SWA 1132 SWA 186

18. 18 Federal Aviation Administration Example Calculation NWA 1176 SWA 1132 SWA 186 “Un-Impeded ” - 14 Min. “Delay” - 6 Min. “Delay”

19. 19 Federal Aviation Administration Potential Benefit Pool Calculation A100VERTICALHORIZONTALexcess distance CarrierFlt. #AC TypeTime (min)Fuel (kg)Time (min)Fuel (kg)Time (min)100-40 (nm)40-0 (nm) NWA1176DC950.075.61.918.90.50.03.2 SWA1132B7375.968.52.575.72.10.214.5 SWA186B73314.090.44.9241.05.80.039.9

20. 20 Federal Aviation Administration 20091016 UAL870 Horizontal Calculation 100 to 40 excess distance: 0 40 to 0 excess distance: 0 Time improvement pool: 0 Fuel improvement pool: 0

21. 21 Federal Aviation Administration 20091016 UAL870 Vertical Calculation Level distance: 0 Time saving pool: 0 Fuel saving pool: 0

22. 22 Federal Aviation Administration 20090703 UAL870 Horizontal Calculation 100 to 40 excess distance: 0.42 nm 40 to 0 excess distance: 6.11 nm Time saving pool: 0.93 minute Fuel saving pool: 122.9 kg

23. 23 Federal Aviation Administration 20090620 UAL870 Vertical Calculation Level distance: 19.1 nm Time pool saving: 1.7 minute Fuel saving pool: 160.7 kg

24. 24 Federal Aviation Administration Additional Fuel on Descent at Top 34 US Airports 2009

25. 25 Federal Aviation Administration Average Excess Time and Total Fuel by Facility 3.1 Minute Avg. Total Fuel a Product of Time, Fleet Mix and Total Volume of Operations JFK ORD ATL DFW 2009

26. 26 Federal Aviation Administration The CASE for Speed Control in Cruise How much of the terminal area inefficiency can be recovered without changing throughput rates?? Assumptions: –No speed adjustments for aircraft at the beginning of a “rush” –Used 1.5 to 5 minutes of absorbed delay as necessary for keeping pressure on the runways aircraft/ANSP flow control based speed –No fuel change estimated for slowing down in the cruise segment –Assumed 30, 60, 90 and 120 minute windows for absorbing time in cruise –If aircraft reaches cruise inside of 30 minutes left in cruise it is not considered in the pool

27. 27 Federal Aviation Administration SAMPLE Impact of Mach Speed on Fuel Burn Maximum Range (MR) is “Cost Index 0” and minimizes fuel burn Long range cruise (LRC) is a compromise between speed and fuel Going slower in cruise burns less fuel ….up to a point! No fuel savings estimated for cruise speed reduction

28. 28 Federal Aviation Administration Methodology for Minutes of Cruise Delay Absorption 1.Calculate time in cruise for each flight Remove Climb (15min) and last 100nm Establish variable for time available for speed reduction 2.Estimate potential time that can be absorbed for varying speed reductions Example…5% reduction on a 90 minute cruise time implies up to 4.7 minutes can be absorbed (90/0.95-90) 3.Time absorbed in cruise is the difference between Potential time above and the Excess (previous slide) Fuel Saved = Excess Fuel x time_saved/excess time

29. 29 Federal Aviation Administration Potential Time savings (US airports 2009)

30. 30 Federal Aviation Administration Potential Fuel savings (US airports 2009)

31. 31 Federal Aviation Administration Potential Savings vs Allowable Speed Reduction

32. 32 Federal Aviation Administration US - 5% max speed reduction

33. 33 Federal Aviation Administration US - 8% max speed reduction

34. 34 Federal Aviation Administration Potential time savings (Europe 2009)

35. 35 Federal Aviation Administration Potential fuel savings (Europe 2009)

36. 36 Federal Aviation Administration Europe 2009 - 5% speed reduction

37. 37 Federal Aviation Administration Europe 2009 - 8% speed reduction

38. 38 Federal Aviation Administration Challenges Need better data on fuel saved by slowing in cruise Implementation Issues remain with: – moving outside an Individual ANSP or Center’s sphere of influence – how to get times to pilots – how to enforce time windows (CTAs) – combining speed control with ground holds for shorter flights – how to handle equity and airline preferences for individual flights – conflict resolutions in cruise impact on achieving CTAs – controller roles and acceptance Role of Simulations? Additional Trials?

39. 39 Federal Aviation Administration Conclusions Potential pools for saving fuel thru speed changes can be estimated with basic ANSP data Fuel savings can be achieved through speed control in cruise –Fuel can be saved both through slowing down and reducing excess time in the terminal area –Fuel Savings from speed control is achieved without increasing capacity or throughput Worldwide implementation of CTA’s is growing and proving that fuel can be saved with speed adjustments today (without the benefit of full 4D trajectory management)

40. Federal Aviation Administration END

41. 41 Federal Aviation Administration Fuel savings from speed control versus flight length (Europe 2009)

42. 42 Federal Aviation Administration

43. 43 Federal Aviation Administration

44. 44 Federal Aviation Administration Vertical Profile View NWA 1176 SWA 1132 SWA 186

45. 45 Federal Aviation Administration Example Calculation NWA 1176 SWA 1132 SWA 186 “Un-Impeded ” - 14 Min. “Delay” - 6 Min. “Delay”

46. 46 Federal Aviation Administration Benefit Calculation A100VERTICALHORIZONTALexcess distance CarrierFlt. #AC TypeTime (min)Fuel (kg)Time (min)Fuel (kg)Time (min)100-40 (nm)40-0 (nm) NWA1176DC950.075.61.918.90.50.03.2 SWA1132B7375.968.52.575.72.10.214.5 SWA186B73314.090.44.9241.05.80.039.9

47. 47 Federal Aviation Administration ANSP Quality of Service has 4 primary focus areas 1.Availability of Direct or Wind Optimal Routes 2.Maximizing Capacity and Throughput (Terminal and En Route) 3.Resilience of Capacity (IMC like VMC, time based separation for wind reduced capacity on final) 4. Managing necessary delay in the most fuel efficient manner (Measuring delay by phase of flight)

48. 48 Federal Aviation Administration Calculating Potential Benefits from Reduced Speed in Cruise Methodology Start with total excess terminal time on a per flight basis –Remove additional terminal time to keep pressure on runways (1.5, 2.5, & 5min) Establish estimate for potential time absorption in cruise Additional Terminal Time into SFO Example Excess Minutes