Green Approaches : 4D-Trajectory Enabled Continuous Descent Approaches

1. Green Approaches:4D-Trajectory Enabled Continuous Descent Approaches Keith Wichman -- Smiths Aerospace FAA New Technologies Workshop III 9-10 January 2007, Arlington Virginia

2. Example: Aircraft capability Thrust Thrust • Entire descent & approach: • Least possible thrust • Highest possible altitude Todays std practice 6~10 step downs Why are A-CDAs not much practiced?

3. Why are CDA’s not used wholesale? • Myth: “CDA’s reduce capacity” • Idle descent vertical and time profiles can vary widely from aircraft to aircraft • This uncertainty drives need for ATC to block large chunks of airspace • Thus, CDA’s practiced today generally off-peak hours and/or sub-optimal descents (least-common-denominator fixed vertical profiles) • Solution: Marriage with 4D-trajectory downlink, and if needed, onboard time-guidance (RTA) functionality supplies ATC with observability and predictability to use CDA’s during dense operations • Requirements: • Aircraft – 4D FMS’s already predict reliable 4D Trajectories (4DT) and guide to Required Times of Arrival. Need appropriate downlink of the 4DT • ANSP – Operational shift toward Trajectory Based Operations (TBO) to incorporate the 4DT and the development of necessary support applications

4. Trajectory-Based Operations • Basis for strategic planning and tactical operations including separation management. • Key concept element for the USA’s NGATS and Europe’s SESAR • Four-dimensional trajectory (4DT) is the cornerstone of Trajectory-Based Operations for improved predictability • “Open-ended” flight maneuvers (such as vectoring) reduce predictability. • “Closed” trajectory-based maneuvers improve predictability. • While designed to optimize an individual flight and reduce pilot workload, modern FMS’s offer much capability that could be tapped by ATM to optimize the whole system. Trajectory-based operations seeks to exploit this functionality.

5. A320 Future Past Today Radar Knowthe current and estimate planned a/c positions Procedural Estimate the current and planned a/c positions Trajectory Know & share the current and planned a/c positions The Paradigm Shift

6. Roadmap • NGATS and SESAR aim to set vision and path to achieve 4DT ATM • In-service operational evaluations represent “forays” into the future: • Validation of concepts • Validation of benefits • Results and data informs decisions of political activities (NGATS, SESAR) • These vanguard activities require effective teaming across domains • ANSP (and equipment suppliers) • Operators (and OEM + suppliers) • Airport Authority • … basis for the integrated system seen by NGATS and SESAR. • The European Commission’s NUP2+ Program is presented here. “Triplets”

7. Terminal Movements with Trajectory-Based Operations • Increased arrival/departure throughput and efficiency. • Increased predictability • Reduced track distances • Reduced voice communications & vectoring • More efficient vertical profiles with reduced fuel consumption. Metering Fix

8. FMS and Avionics

9. Required Time of Arrival • Algorithm is based on speed variation. • Fixed lateral path • Fixed cruise altitude • Required Time of Arrival is enabled for any point in the flight plan. • Available on 737 aircraft since 1986. • Demonstrated performance in trials with SAS in 2001. • Future enhancements: • Improved control to the runway accounting for fixed speed segments. • Compensation for control error tolerance when reporting trajectory early in the flight. • Include lateral offset and/or cruise altitude variation when additional delay is required.

10. Typical flight data Latest Arrival Time Required Time of Arrival Earliest Arrival Time Cruise FL350 Climb Descent Phase RTA to the Runway • Results were obtained in trials with SAS in 2001 (33 flights). • Performance is better when controlling to start of arrival due to more speed-control authority. • Limited control late in descent due to constrained speed.

11. ATC AOC Intent Bus in B737 U10.6 FMS Current A/C State and Trajectory Predictions First application in 2005 –Provide FMS 4D trajectory to ATC! • ARINC 702A-1 Trajectory Bus • Aircraft current-state information 2Hz • Aircraft 4D trajectory predictions (Intent) • Each minute or when FP changes • Full trajectory to runway • Includes vertical wpts and turns • Dedicated ARINC 429 Bus • As per ARINC702A-1 ARINC429 Trajectory Bus ACARS in 2007! • ACARS messages added for interim use in flight trials • By REQ from ATC • One-time or periodic downlink

12. Turn Direction Turn Radius Lat / Lon Altitude Time! Point Type ARINC 702A-1 4DT Data for Stockholm to Malmo Flight • Route: ESSAESMS10 • ---------starts here----------- • 1,,,N59397E017581. • 1,R,113,N59401E018009,108,090122. • C,,,N59376E018019,500,090227. • 0,R,557,N59359E017585,769,090306. • 0,L,934,N59302E017443,1279,090456. • 0,,,N59070E017184,2511,090907. • 0,R,1893,N59044E017155,2604,090932. • B,,,N58515E016548,3032,091149. • 8,,,N58380E016335,3500,091408. • 0,,,N58366E016312,3500,091423. • 0,,,N57592E015342,3500,092051. • 0,,,N57388E015041,3500,092420. • 0,,,N57024E014122,3500,093032. • 0,,,N56455E013489,3500,093323. • 9,,,N56354E013354,3500,093504. • 0,L,981,N56345E013340,3450,093513. • B,,,N56295E013331,3223,093553. • 0,L,1249,N55550E013268,2010,094058. • 1,R,406,N55247E013335,1002,094623. • 1,R,215,N55210E013322,886,094712. • C,,,N55189E013229,500,094951. • 0,L,171,N55198E013275,459,095034. • 0,,,N55276E013235,148,095357. • 0,,,N55314E013227,29,095528. • 1,,,N55329E013212:00002926 • EOT finalLDU=1, CRC=3483 0,L,934,N59302E017443,1279,090456

13. NUP 2+ Partners ANS Airlines Airports Industrial group

14. ANSP - Airport LFV CIES NUP2+ Trajectory Usage Flight operations began January 19th, 2006 ACARS ARINC 702A-1 standard AOC SAS RC Hermes

15. Trajectory Reporting • ARINC 702A Supplement 1 was defined for early implementation. • Implemented in 737 FMS with U10.6 software – dedicated ARINC 429 bus. • ACARS downlink of trajectory intent information as interim datalink. • European Commission (EC) supported activity, NUP2+, in Sweden and Austria. • Operational evaluations began in October 2005 including: • RTA contracting to the runway. • Green Approaches (CDAs) with FMS 4D trajectory to preserve capacity. • Slot Swapping • Ground Holding • First air/ground operation connectivity of FMS 4DT with Arrival Manager… • Airlines are deriving demonstrable benefits (punctuality, fuel). • Operations now in medium traffic conditions… moving toward peak traffic.

16. First 4D FMS Trajectory Downlink

17. Continuous Descent Approach (CDA) Cost Index (CI) CI = time cost / fuel cost Altitude Cost Fuel Cost CDA Dive and DriveApproach Time Cost Distance Speed Controlled Time of Arrival • Generated by a Time-Based Metering system to merge traffic from metering fixes to a runway. • A key capability of an FMS is to “self-deliver” to a specified waypoint at a Required Time of Arrival (RTA). • The FMS efficiently operates a flight with a user selected Cost Index (CI) and a Continuous Descent Approach (CDA). • Accurate ETAs need to be downlinked from the aircraft to close the loop with ground control.

18. ANSP Integration of 4DT in Arrival Management

19. Aircraft performs Green Approach 3min before ToD ground system automatically request 4DT in order to get accurat ETA/RTA from aircraft. ATC sends Green Approach STAR to aircraft. This STAR is defined all the way to ILS. Pilot updates FMS and pushes more accurate ETA. OFF message including ETA for Arlanda arrival is sent via data link Expected STAR is sent back to the aircraft. ATC request RTA (close to the latest down linked ETA in order to be almost sure that aircraft will accept) 2 Pilot updates FMS and pushes more accurate ETA. 7 6 5 9 4 8 1 3 40min before ETA ground system automatically requests full remaining 4D trajectory description in order to be able to plan for this aircraft and merge it with ordinary traffic. Based on this the Approach controller can chose to assign an RTA constraint to the aircraft (on the second) Aircraft accepts RTA. Strategic Communication Description Climb Descent En-route Lift-Off

20. Example from live trial Reply: RTA unachievable RTA Accepted In the new downlinked 4DT messages, the time separation at HMR had increased from 1 to 2 minutes Via 4DT downlink SAS075 confirms GA HAMMAR1V with ETA 06:49 RTA Accepted Via 4DT downlink SAS2059 confirms GA HAMMAR1V with ETA 06:50 Controller want 180 second separation. Send RTA 06:47:00 to SAS075 Sends RTA 06:48:00 to SAS075 and RTA 06:51:00 to SAS2059 Controlling to time resulted in physical separation of 10NM at OM

21. Benefits of the 4DT Approach 1st 4DT downlink 19th of October 2005 1st 4DT Flight 19th of January 2006 General 4DT operation from 26th of March 2006

22. NUP 2+ ResultsFuel Savings CDA vs Standard Approach

23. TRANSCAP Noise results

24. Next step Arlanda: Mixed mode operation 160kts OM 10NM 5NM

25. Next step Arlanda: Mixed mode operation

26. SAS Sweden Experience from 800+ Green Approaches • More than 650 Green Approaches flown to date… (and counting) resulted in: • 204 Metric Ton CO2 reduction yearly • 715 kg of NOx reduction yearly • 130,000 kg of fuel saved • SAS-Sweden 36,000 Green Approaches per year into Stockholm alone • $5.8M fuel reduction yearly • 23,000 Metric Ton CO2 reduction yearly • 79 Metric Ton of NOx reduction yearly • Large noise reductions (being quantified) • SAS and LFV expanding Green Approaches throughout domestic Sweden

27. NUP2+ Steps for 2007 • Install VMMR to downlink 4DT via ADS-B • Install EFBs for surface movement guidance operations • Install enhanced FMS software for better predictions and RTA • Conduct controller simulations with mixed equipage and high traffic • Operate regularly in peak traffic (>57 mvts/hr), mixed equipage, CDAs and validate capacity unchanged or increased. • Infuse results into JPDO-NGATS and SESAR • Also… • Plans firming to expand the operations in 2007 to adjacent regions in “core-Europe” in order to begin developing end-end benefits to participating airline operations.