1. Resource Allocations within Constrained Airspace October 31, 2001 Metron Aviation, Inc. Robert Hoffman, Ph.D.

2. 10/17/20012 What is equitable allocation of limited resources (EALR)? an allocation scheme is deemed fair, or equitable, if the parties with a stake in the allocation process deem that their individual allotments are reasonable and in accordance with the treatment received by their competitors, given the operational constraints on the procedure itself and the original motivation for the allocation.

3. 10/17/20013 What is EALR? – Airport Case Arrival Demand Capacity Controlled Arrivals Airport Case: Assignment of available capacity to demand –Assign Airport Arrival Slots by Delaying Some Flights –In a Fair Manner

4. 10/17/20014 Sector Demand What is EALR? – Sector Case Allocate Sector Capacity –Spatial allocation: re-Route Some Flights –Temporal allocation: delay Some Flights –In a Fair Manner

5. 10/17/20015 What is EALR? - Interdependence West-East Traffic DTW Overhead traffic favored over departures (easiest flow to shutoff) Need for flow balancing: consideration must be given to departures

6. 10/17/20016 Collaborative Decision Making (CDM) Trends Movement away from central-decision making No more black box solutions FAA often answers to carriers for rationale of traffic flow initiatives –daily basis –regular CDM meetings: air carrier feedback

7. 10/17/20017 Equity-Efficiency Tradeoff Efficient but not equitable (En route example) –Let overhead traffic go; hold merging departures –Throughput maximized but not fair to departures Equitable but not efficient (GDP example) –Ground all flights by the same amount –Equity achieved but airport throughput suffers

8. 10/17/20018 Why do we need equity? User satisfaction –FAA is a service provider Promotes User participation –data submission –collaborative flow management

9. 10/17/20019 The Many Facets of Equity Long haul Vs. Short haul flights GA Vs. Scheduled Carriers Regional Vs. Majors Overhead stream Vs. Departures Equity across flights, carriers, ARTCCs, airports,... No single vantage point serves for all occasions

10. 10/17/200110 How To Measure Equity? What is the resource to be rationed? (e.g., arrival slot) Who is vying for the resources? How to quantify fairness? (e.g., FSM variance metrics) Must have: –Participant (FAA and carrier) feedback –Understanding of contextual nuances and TFM objectives

11. 10/17/200111 User Participation Virtual arrival slots created in anticipation of reduced capacity Slots rationed to carriers/flights in order of scheduled arrival time (RBS) Carriers re-allocate slots among their operations

12. 10/17/200112 Group B Group A FCA En Route Competition for Alternate Airspace

13. 10/17/200113 Ground delay Origin Destination Downline delays Air delay Total Imposed Delay = (Ground delay) + (Air delay) + (Downline delay) More Global Equity via Total Imposed Delay

14. 10/17/200114 Equitable Allocation of En Route Resources How to allocate constrained routes in an equitable manner while incorporating User preferences? How to encourage submission of early (and accurate) User intent? ? Ground delay Reroute Original Route Alternative Route

15. 10/17/200115 Some Possible Rationing Concepts Equitable distribution among traffic flow classes (e.g., DFW arrivals, east-west traffic) RBS-like assignment of en route resources (route slots). But then what is OAG time? Preference given to those flights with existing delays Delay is weighted sum of notice time and scheduled time

16. 10/17/200116 Issue: Analysis of Enroute Resource Limits Enroute capacity has not been systematically measured –How can resources be rationed if they have not been quantified? –Data is Available Recommendation: –Develop resource-throughput analysis capability for all NAS enroute elements Average and peak performance for all sectors over long periods Correlation with weather events and TFM actions

17. 10/17/200117 Issue: Communication Channels Dynamic response to changing capacity is limited by communication channels –Strategic Planning Team and ATCSCC communicate through TMUs to supervisors to controllers –Multiple layers of telephone communication slow the response of the ATC system Recommendation: –Initiate study of communication procedures and support tools that could facilitate more direct communication between ATCSCC, ARTCCs, AOCs,...

18. 10/17/200118 Issue: Demand/Capacity Uncertainty Equitable Allocation of Limited Resources is subject to uncertainty –TFM Planning Time Horizon –Weather/Capacity Uncertainties –Demand Uncertainties –Data Quality Recommendation: –Develop research thrust in demand/capacity uncertainty

19. 10/17/200119 Demand Variability ZOB48

20. 10/17/200120 Demand Variability ZOB48

21. 10/17/200121 Demand Variability ZOB48

22. 10/17/200122 Demand Variability ZOB48

23. 10/17/200123 Flights Flown but did not File ZID88 37 Flights Filed for ZID98 5 Flights Filed for Lower ZID Sectors + 18 Flights Filed Around ZID88 60 (out of 218) Flew but did not File ZID88 _______________________________________________________

24. 10/17/200124 Issue: Airport Surace Operations Airport surface operations create a black hole in current TFM planning –What are the delays? –When will a flight depart? –This contributes significantly to the demand uncertainty issue Recommendation: –Integrate research and development of the surface management system with TFM tools SMS can feed accurate predictions of flight departure times to FSM for GDP planning

25. 10/17/200125 Overall EALR has many manifestations There are clear tradeoffs between equity and efficiency The real question is: do the system operators perceive there to be a proper balance between efficiency and equity

26. 10/17/200126 Metron EALR Activities Equity Analysis and Modeling (POET, FSA, FSM) Distance-Based GDPs Multi-Airport, Multi-Fix GDPs Departure Delay Predictor Equitable Allocation of En Route Resources C-Flow Complexity Metrics/Dynamic Density