Definition
A traffic management process administered by the Air Traffic Control System Command Center that identifies flights which will fly through a constrained area of airspace and assigns each affected flight an Expect Departure Clearance Time (EDCT). The program meters the rate at which aircraft enter the constrained airspace, typically when severe weather, volume, or other limitations reduce the capacity of an en route sector or region.
Plain English
When a chunk of airspace can only handle a limited number of flights — usually because of weather or congestion — the FAA spaces out the aircraft heading toward it by giving each one a specific time it can leave the gate. AFP is the system that figures out who is affected and what their delay should be.
Context Anchor
Pilots may encounter AFPs during preflight planning, in traffic management notices, or when ATC or flight service explains why a departure time or route has changed.
Derivation
"Flow" here refers to managing the flow of traffic — the rate at which aircraft move through a piece of sky — much like controlling water flow through a pipe. The term frames airspace as something with a finite throughput that must be regulated when demand exceeds capacity.
Why Pilots Care
An active AFP can impose ground delays on departures, change expected departure clearance times, and affect fuel planning and crew duty limits.
Intuition Check
Do not read “program” here as a training course or computer app. In this FAA use, it means an organized traffic-control procedure for managing aircraft through a constrained area of airspace.
Example Sentence 1
Dispatch advised that an AFP was active over the northeast corridor due to thunderstorms, and our flight received an EDCT pushing departure back forty minutes.
Example Sentence 2
Our release time was adjusted by twenty minutes because of the AFP metering traffic into the sector.