7. Overview of GDPs and Ground Stops – July 1

Ground Delay Programs (GDPs) and Ground Stops (GSs) at the Four Major Airports in Canada (July 1 - August 9, 2022

A Ground Delay Program (GDP) is an air traffic management process administered by the flow manager whereby aircraft are held on the ground. The purpose of the program is to support the air traffic management mission and limit airborne holding. It is a flexible program and may be implemented in various forms depending on the needs of the air traffic system. GDPs provide for equitable assignment of delays to all system users.  (Examples include airport construction, unplanned absences of staff, weather anomalies and unusually high volumes of air traffic in a short timeframe).

A Ground Stop (GS) is a procedure requiring aircraft that meet specific criteria to remain on the ground. The GS may be airport specific, related to a geographical area, or equipment related.  (Examples include telecommunication outages, thunderstorms and ground infrastructure unserviceabilities).

The real difference between the two is that a GS is absolute, and no one moves.  A GS is usually related to weather or some type of airport infrastructure issue – it is rarely air traffic control-related. A GDP is a situation where aircraft are still allowed to depart but at a delayed time.