collaborative decision making at the faa/ato

Date: 18 February 2008

Federal AviationAdministrationCollaborative Decision

Making at the FAA/ATO

A look at how CDM is applied in the U.S.

2 2Federal AviationAdministration

CDM in the US - Outline

• Overview of the problem CDM is addressing• Early successes with FAA/ATO data sharing• Airport arrival constraints and managing

equity thru ground delay programs• Airspace flow program (AFP) focused on en

route constraints• CDM tools in development


5

5.5

6

6.5

7

7.5

8

8.5

9

Jan-

00

Jul-0

0

Jan-

01

Jul-0

1

Jan-

02

Jul-0

2

Jan-

03

Jul-0

3

Jan-

04

Jul-0

4

Jan-

05

Jul-0

5

Jan-

06

Jul-0

6

Jan-

07

Jul-0

7

Ann

ual O

ps (M

illio

n)

Annual Ops Monthly Delay

0

5

10

15

20

25

30

Avg

. Tot

al D

elay

Annual Delay

Major US Airports - Demand vs. Delay


ATO Dash Board


Early CDM Accomplishments

NAS status information is available on the Internet at http://www.atcscc.faa.gov/ois - Special Use Airspace data is available- Special Use Airspace data is availableRunway visual range data is available at 28 airportsRunway visual range data is available at 28 airportsTRACON Radar tracks available to airlines at major TRACON Radar tracks available to airlines at major airportsairports

http://www.atcscc.faa.gov/ois


Sample Benefits of FAA Data Sharing• Approach radar tracks available to Airlines

– Enhanced terminal area situational awareness to Airline Operations Centers

• Reduced the number of diversions– Estimated 3 - 5 diversions avoided per week during inclement

weather ($5K - $100K each)

• Improved recovery from missed approaches

– Improved gate management at ramp tower

• Increased accuracy on touchdown and gate times• Improved management of airline/airport resources


Highlights: CDM for Traffic Flow Management in the US

• Initial CDM concepts were developed starting in the mid-90’s.

• CDM-based decision support tool (FSM – the flight schedule monitor) and information exchange network (CDM-net) became operational in 1998 for the planning and control of ground delay programs (GDP’s).

• Broad participation by FAA operations personnel and nearly all air carriers and more recently business jet operators.

• “CDM-Group” meets regularly to develop new computer-based tools and operational procedures, to analyze air traffic data and problem areas and to solve pressing problems.


CDM Concepts and Features• Philosophical components:

– improved information and common situational awareness – distributed control and decision making:

• Decision made by most appropriate party• Economic tradeoffs made by appropriate flight operator

– strong and continuous interaction among airspace system managers and flight operators

• FAA—airlines• airline—airline; peer pressure

• Technical accomplishments:– new fair allocation principles– shared decision support tool (FSM)– shared communications network (CDMnet)– Airspace Flow Program

• Reliance on data analysis and objective critique


Motivation for Ground Delay Programs: airline schedules “assume” good weather

SCHEDULED ARRIVALS AND CURRENT ARRIVAL RATE BOUNDARIES, REDUCED RATE CONDITIONS

0

2

4

6

8

10

12

14

16

18

7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

Arrivals Facility Est. Model Est.

SFO: scheduled arrivals: VMC airport acceptance rate:IMC airport acceptance rate:


Flight Schedule Monitor (FSM)• Decision support tool to monitor and control

arrival demand at airports• Receives regular flight list updates from ETMS• Provides graphical and statistical displays

of arrival demand

Flight

ListsHourly Demand Graphs


Ground Delay Programs

delayed departures

delayed departures

delayed departures

delayed arrivals/no airborne holding

control = flight departure timedecision variable = flight arrival time (slot)


Ground Delay Programs (GDPs)• Used to control excess arrival demand at airports• Executed through FSM• Assigns ‘arrival slots’ to flights based on airport capacity• Releases each flight from its departure airport in time to

meet its arrival slot

Excess demand …… delayed to match

capacity


Equity is the Challenge in Assigning Airline DelayCDM provides a Slot Exchange:

- Intra-Airline Slot Exchange -- Cancellation and Substitution Process: slot-to-flight allocation viewed as slot-to-airline allocation; airlines can reassign slots they “own” to their flights in any way possible – as part of process they may cancel certain flights.- Inter-Airline Slot Exchange -- Compression: implements a type of inter-airline slot exchange in situation where airlines are assigned slots they are otherwise unable to use.


Arrival slot allocationsNormal Capacity:

arrival rate = 60/hrDegraded Conditions:arrival rate = 30/hr


GDPs under CDM

Resource Allocation Process:• FAA: initial “fair” slot allocation [Ration-by-schedule]• Airlines: flight-slot assignments/reassignments

[Cancellations and substitutions]• FAA: periodic reallocation to maximize slot utilization

[Compression]

Estimated that millions of minutes of delay are saved each year due to better use of available capacity.


Convective Weather Problem


GDPs as an Airspace Tool Control the Wrong Flights

• Many flights in the FCA are not controlled because they aren’t going to the GDP airports

Uncontrolled flights in the FCA

• Many flights not in the FCA are unnecessarily delayed because they are going to GDP airports

Delayed flights not in the FCA


Airspace Flow Programs (AFPs)

• Uses FSM scheduling technology matched airspace demand and capacity problems

• Lets traffic managers apply coordinated delays to flights overloading en route resources

Create a Flow Constrained Area

ETMS manages data exchange

Meter flights in the FCA through FSM

FCA parameters FCA flight list

Flight delaysUpdated demand


AFP Operations• Uses established infrastructure and procedures for distributing

and maintaining controlled departure times• Customers can avoid imposed ground delay by routing around

constrained area– Resulting drop in demand will reduce all delay through ‘compression’

• Programs can be revised as demand and weather change, to make full use of all available capacity


AFP Benefits• Much more precise control of airspace demand

– Reduce Ground Stops, diversions and airborne holding

versus

• Distribute delay fairly among flights contributing to the excess demand

• Avoid imposing unnecessary delay on flights that don’t use constrained resources

• Provide customers more predictability and flexibility / options• The AFP is a building block for airspace congestion management

Before AFP With AFP


Other CDM Activities

• Concept Engineering Activities– TFM Surface Data Initiative (TSDI)– Surface Traffic Count Monitor (STCM)– Departure Flow Management (DFM)– Route Availability Prototype Tool (RAPT)


END

collaborative decision making at the faa/ato

Documents