Ground delay program

Template:Linkless == Headline text ==Bold text Air Traffic Control Ground Delay Program

Ground Delay Program

An Air Traffic Control Ground Delay Program or FAA Flow Control is a traffic flow initiative that is instituted by the Federal Aviation Administration in the United States Air Space System.

This program is usually instituted when the following events occur at an airport

Inclement Weather (i.e. reduced visibility, thunderstorms, snow), an abundance of airborne inventory to a destined airport or enroute to another airport in the same line of flight, an aircraft incident, a closed runway(s), a condition that requires increased spacing between aircraft, such as ILS approaches vs. VFR approaches.

The main factor for determining if a ground delay program is needed is a number called Airport Arrival Rate or AAR. This number is set by the controlling air traffic facility. When the AAR is reduced by the supporting ATC facility, the ATCSCC, Air Traffic Control System Command Center in Washington D.C. institutes a Ground Delay Program.

These programs usually last for several hours and average delay minutes can vary as conditions change at the said ATC controlled area.

Each aircraft enroute to a particular area is assigned an EDCT (Expect Departure Clearance Time). This is also called a "wheels up time” and is when the FAA expects to give takeoff clearance. Aircraft have +/- 5 minutes on either side of their EDCT to depart of they will be assigned a new EDCT and expect further delays.

When conditions improve, or when demand decreases, the ATCSCC begins running compressions. This is when the ATC facility can accept more traffic or users, i.e. airlines cancel flight plans causing openings. This causes other EDCT times to change and decrease delays.