Adaptive compression is a mechanism used to help ensure that all slots in a Ground Delay Program (GDP) or Airspace Flow Program (AFP) are used.
The general idea is that a background process within FAA’s Traffic Flow Management Systems (TFMS) will automatically:
- Monitor a GDP or AFP for open slots
- Identify those slots that are in danger of going unused
- Move other flights earlier to take advantage of those open slots
- Move the open slots later
- Update the databases with the changes
- Send notifications in the form of Expect Departure Clearance Time (EDCT) updates to the flight operators about the changes
The benefits of Adaptive Compression are:
- Higher utilization of the airport/airspace capacity
- Customers can be more proactive regarding constraints, restrictions, etc.
- Reduced workload for the ATCSCC specialist/ATC Coordinator
What does this mean to operators?
When a flight is issued an EDCT as a result of a GDP or an AFP, the crew can expect that time may change as the program runs its course. This could mean that the EDCT will move earlier or later.
Since these changes are not sent to each individual operator (as they would be sent to dispatch in an airline situation), operators are encouraged to remain aware of what is happening in the NAS and to check their EDCT times regularly by either using the FAA’s EDCT Lookup Tool, by communicating with their flight plan service provider, or by staying in touch with ground control or clearance delivery.