1. © 2003 The MITRE Corporation. All rights reserved. F064-B03026 A Phased Approach to Increase Airport Capacity Through Safe Reduction of Existing Wake Turbulence Constraints ATM 2003 23-27 June 2003 Dr. Anand D. Mundra, Wayne W. Cooper, Benjamin S. Levy, Clark R. Lunsford, Arthur P. Smith and Jeffrey A. Tittsworth from MITRE Steven Lang from the FAA

2. © 2003 The MITRE Corporation. All rights reserved. 2 Wake Turbulence Program Supports OEP - AW-5: Maintain Optimum Runway Usage at Airports with CSPRs –AW-5.1: Support Simultaneous CSPR Approaches –AW-5.2: Wake Turbulence R&D for Enhanced CSPR Operations –AW-5.3: Along Track Separation (ATS) in Reduced Visibility

3. © 2003 The MITRE Corporation. All rights reserved. 3 Early Indications Verified by Structured Analysis Preliminary SFO studies indicated CSPRs were real opportunity to reduce wake constraints and increase capacity –Parallel approach strategies can be developed that assure wake mitigation –Initial assessment of 28 months of wake data shows near-threshold lateral transport from large and small aircraft is much less than 2500 ft. CAASD, MITLL and group pursued a structured analysis of candidate solutions and airports –25+ candidate procedures at 35 top delayed airports –Findings supported the early indications to focus on CSPRs

4. © 2003 The MITRE Corporation. All rights reserved. 4 Candidate Procedure and Airport Selection Process Identify Candidate Procedures Formulate Detailed Procedure Rules Simulate Theoretical Capacity Increase Simulate Benefit with Historical Demand Identify Candidate Airports Operational Considerations Refine Procedure and Airport List Selected Procedures and Airports

5. © 2003 The MITRE Corporation. All rights reserved. 5 Traffic Distribution by Weight Class for Airport Detailed Procedure Separation Rules Control Parameters Run Simulation Experiment Distribution of Spacing Precision Calculate Throughput Mean and Standard Deviation Tabulate Experiment Throughput Iterate to Produce Required Number of Experiments Runway Pair and Approach Geometry Landing Speed Distribution by Weight Class Monte Carlo Capacity Simulation

6. © 2003 The MITRE Corporation. All rights reserved. 6 Output from Selection Process Near-term solution: modified CSPR 2500 ft. rule Mid-term solution: Wind-dependent CSPR departure procedure Long-term solution: NASA’s Wake Vortex Avoidance System (WakeVAS) applied to CSPR and single runway arrivals and departures

7. © 2003 The MITRE Corporation. All rights reserved. 7 Implications of Proposed Change to Current 2500 ft. Rule For an airport with runways separated by at least 1000 ft.: Minimum of 1.5 nm stagger between flights on adjacent parallel approaches to mitigate collision risk No change to in-trail separation behind Heavies and 757s on adjacent parallel approach No change to any current in-trail separation standards for flights on same approach New procedure could potentially be used down to Cat I ceiling/visibility minima

8. © 2003 The MITRE Corporation. All rights reserved. 8 Simulated Capacity Increase for Proposed Change (aircraft/hr) Capacity benefit is in additional arrival slots available per hour during conditions when only current alternative is a single runway IFR approach operation Wakes not a factor behind Large aircraft for trailing aircraft on parallel approach spaced 1000 ft. or more laterally from leader Wakes not a factor behind Small aircraft for trailing aircraft on parallel approach spaced 700 ft. or more laterally from leader Simulations currently assume dedicated arrival operation

9. © 2003 The MITRE Corporation. All rights reserved. 9 Upcoming Activities Supporting Near-Term Solution Instrumenting STL with wake sensors to determine lateral bounds of wake transport by aircraft category Completion of SFO SOIA analysis and implications on modified 2500 ft. rule Flight Standards safety analyses for 1.5 NM staggered –Collision risk analysis –Wake vortex safety analysis Air traffic control (ATC) feasibility: Being addressed via Human In The Loop experimentation with controllers Pilot, controller and other stakeholder issues addressed through WakeNet USA

10. © 2003 The MITRE Corporation. All rights reserved. 10 Implications of SFO Wake Data 28 months of In Ground Effect (IGE) data analyzed –About 1 qtr million vortices from Large aircraft –Vortices correlated with ASOS data –Full range of crosswind components being analyzed –Wake data being correlated with ceiling/visibility –Transport time used to approximate 1.5 NM (45 sec) and 2.5 NM ( 75 sec) in trail –Initial indications are very positive of the near-term goal (modified 2500 ft rule) being achievable Approximately 2,000 flights tracked Out of Ground Effect (OGE) –Confirms wakes transport with the wind –Greatest transport observed for wakes that descended

11. © 2003 The MITRE Corporation. All rights reserved. 11 STL Near-Term Concept Human In The Loop Experiments At CAASD ATM Lab Tower Cockpit Simulate feeder and final terminal approach positions Run multiple experiments with differing spacing for departures Get controller feedback related to perceived workload Simulate local controller release of departures between arrivals Investigate issues with single vs. dual departure operation under various demand conditions Show pilot community how procedures will work in practice Look at Traffic Collision Avoidance System (TCAS) use during procedure Pilot workload issues Terminal

12. © 2003 The MITRE Corporation. All rights reserved. 12 STL Departures 1300-ft 30R 30L 1500-ft Wind Direction Under current rules a Large departing 30L must wait three minutes after Heavy departs 30R since it is considered an intersection takeoff In this situation, the wake is obviously not a factor and no waiting should be required

13. © 2003 The MITRE Corporation. All rights reserved. 13 Wind-Dependent CSPR Departures Operational experience suggests weather systems set up near airports and provide predictable crosswinds that last for a day or more These crosswinds may be strong and predictable enough to allow independent departures on the upwind runway Mid-term effort will investigate the following questions –Do crosswinds occur with sufficient strength, predictability and duration to ensure safety? –Do they occur often enough at the peak departure times to provide benefit? –At what airports? –What are the operational requirements? –Can a solution be designed to meet those requirements?

14. © 2003 The MITRE Corporation. All rights reserved. 14 Simulated Capacity Increase for Mid-Term Departure Procedure (aircraft/hr) Benefits increase with percentage of Heavy aircraft (e.g., LAX, SFO) Benefit increases where intersection departures are no longer needed (e.g., STL 12L as upwind) Benefits based on departures-only simulation on CSPRs Airport capacity benefits based on tools and approach used for near-term (described earlier)

15. © 2003 The MITRE Corporation. All rights reserved. 15 Wake USA Participants ATB ATP AOZ AFS FAA AUA AAR Volpe Boeing NASA LMI MITLL CAASD NATCA Pilot Unions NWRA CTI FAA and DOT NASA FFRDC Union Industry

16. © 2003 The MITRE Corporation. All rights reserved. 16 Wake Turbulence Terminal Procedure Development Timeline Timeline Near-Term CSPR Procedures: SOIA, 2500 ft. rule (FAA) Mid-term:Wind-Dependent CSPR Departures (FAA/NASA) 20042006 Long-term: Active Wake Avoidance Solution (Primarily NASA) 2010 Wake Alleviation (NASA Only) 2020 International Coordination: European/FAA/NASA Action Plan

17. © 2003 The MITRE Corporation. All rights reserved. 17 Backup Slides

18. © 2003 The MITRE Corporation. All rights reserved. 18 1.5 NM Staggered Approaches at STL Stagger 3500 Feet 12R 12L 5 or 6-NM to Lead Aircraft in Next Group for Departures or After a Heavy/757 1300 Feet Separation Within Group Spacing is at least 1.5 NM, but no more than 2.5 NM

19. © 2003 The MITRE Corporation. All rights reserved. 19 CSPR Pairs (700 ft to 2499 ft.) with Current or Planned Simultaneous Use 1 Current CLE runway is 6/24, but the 2001 FAA Aviation Capacity Enhancement (ACE) plan documents it as 5R/23L. CLE is included in the list as discussions with the facility have indicated their intent to use the future CSPR both for simultaneous arrivals and departures. 2 DTW is included in the list as the facility has indicated that it would be desirable to use the CSPR simultaneously for departures, although it does not currently use them in this way. 3 MDW is included on the list, as a CSPR is listed as being in simultaneous use for both arrivals and departures, although the called rates indicate a single approach and departure stream.

20. © 2003 The MITRE Corporation. All rights reserved. 20 >= 700 ft. < 2500 ft. 2.5 / 3 / 4 / 5 / 6 nmi. staggered when visual approaches can not be conducted (IMC and Marginal VMC) and runway center lines are separated by less than 2500 ft. >= 2500 ft. 1.5 nmi. staggered when visual approaches can not be conducted (IMC and Marginal VMC) and runway center lines are separated by 2500 ft. or more Independent approaches during visual approaches for runway center lines separated by 700 ft. or more 036912151821242730 nmi. 29.0 total nmi. to land 7 aircraft in example 18.5 total nmi. to land 7 aircraft in example 15.0 total nmi. to land 7 aircraft in example 036912151821242730 nmi. 036912151821242730 nmi. S7SL SLLLH S7SL LLLHS S L 7 L S L L HS Current FAA Final Approach Spacing Rules for Parallel Runways Visual approaches Below visual conditions

21. © 2003 The MITRE Corporation. All rights reserved. 21 Potential Change in Current 2500 ft. Rule for Dependent Parallel Approaches Current rule treats all leading aircraft the same regardless of weight class Proposed concept treats each weight class based on its worst case lateral wake transport