Ground Delay Program and EDCT Program notices are transmitted to ATC facilities in a format that tells the receiving facility the type of program, the reason for the program, and when they should receive an update.
On the morning of November 19, 2009—the day the FAA’s NADIN flight plan system failed—the massive Houston Intercontinental Airport apparently had so many delayed airplanes taking up ramp space that they ground-stopped all inbounds. Here it is, printed on a convenient flight progress strip.
