Definition
A traffic management procedure used by air traffic control to regulate the flow of arriving aircraft to a specific airport when arrival demand is expected to exceed the airport's acceptance rate. Under a GDP, departing aircraft bound for the affected airport are held on the ground at their origin and assigned a delayed departure time so that arrivals at the destination are spaced out and do not exceed capacity.
Plain English
When too many aircraft are scheduled to land at one airport — usually because of weather, runway closures, or other capacity limits — air traffic control keeps some flights on the ground at their starting airport and gives them a later departure time. This spreads arrivals out so the destination airport can handle them safely.
Context Anchor
Pilots most often encounter a GDP during flight planning or before departure when weather, runway limits, or heavy traffic reduce how many aircraft an airport can accept.
Derivation
The name describes the procedure plainly: a program that delays aircraft on the ground (rather than airborne) to manage flow into a destination. Holding aircraft on the ground is safer and far less expensive than holding them in the air.
Why Pilots Care
It replaces airborne holding with ground holds, saving fuel and reducing the chance of diversions or safety issues caused by low-altitude circling.
Analogy
It is like holding cars at a parking-lot entrance so the lot does not overflow. The delay happens before entry, not after everything is already crowded inside.
Intuition Check
A Ground Delay Program does not mean the airplane has a mechanical problem or that the pilot did something wrong. It means the traffic system is slowing departures so arrivals remain manageable at the destination.
Example Sentence 1
Dispatch advised that a GDP was in effect at the destination, and our departure was pushed back ninety minutes to meet the assigned EDCT.
Example Sentence 2
After the Ground Delay Program was lifted, we were cleared to push back without further restriction.