resource allocations within constrained airspace october 31, 2001 metron aviation, inc. robert...
TRANSCRIPT
Resource Allocations within Constrained Airspace
October 31, 2001
Metron Aviation, Inc.
Robert Hoffman, Ph.D.
10/17/2001 2
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.
10/17/2001 3
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
10/17/2001 4
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
10/17/2001 5
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
10/17/2001 6
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
10/17/2001 7
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
10/17/2001 8
Why do we need equity?
• User satisfaction– FAA is a service provider
• Promotes User participation – data submission
– collaborative flow management
10/17/2001 9
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
10/17/2001 10
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
10/17/2001 11
0
20
40
60
80
100
120
140
160
1
62
123
184
245
306
367
428
489
550
611
672
733
794
Cumulative minutes (from start of program)
Cum
. Sub
s (%
of f
lts in
gdp
)
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
10/17/2001 12
Group B
Group A
FCA
En Route Competition for Alternate Airspace
10/17/2001 13
Ground delay
Origin Destination
Downline delays
Air delay
Total Imposed Delay = (Ground delay) + (Air delay) + (Downline delay)
More Global Equity via Total Imposed Delay
10/17/2001 14
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
10/17/2001 15
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
10/17/2001 16
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
10/17/2001 17
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, ...
10/17/2001 18
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
10/17/2001 19
Demand Variability ZOB48
1200 Outlook for 1600-2000 (9.28.01)
0
10
20
30
40
50
60
Predicted Actual Predicted Actual Predicted Actual Predicted Actual
Time
Fli
gh
ts Pop-up
Common
1600 1800 19001700
10/17/2001 20
Demand Variability ZOB48
1300 Outlook for 1600-2000 (9.28.01)
0
10
20
30
40
50
60
Predicted Actual Predicted Actual Predicted Actual Predicted Actual
Tim e
Fli
gh
ts Pop-up
Common
1600 1800 19001700
10/17/2001 21
Demand Variability ZOB48
1400 Outlook for 1600-2000 (9.28.01)
0
10
20
30
40
50
60
Predicted Actual Predicted Actual Predicted Actual Predicted Actual
Time
Fli
gh
ts Pop-up
Common
1600 1800 19001700
10/17/2001 22
Demand Variability ZOB48
1500 Outlook for 1600-2000 (9.28.01)
0
10
20
30
40
50
60
Predicted Actual Predicted Actual Predicted Actual Predicted Actual
Time
Fli
gh
ts Pop-up
Common
1600 1800 19001700
10/17/2001 23
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
_______________________________________________________
10/17/2001 24
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
10/17/2001 25
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
10/17/2001 26
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