Aeronautical Information Manual
AIM 6-2-2
Transponder Emergency Operation
This reproduces published FAA reference text for study. It does not replace the current official FAA publication or regulation.
When a distress or urgency condition is encountered, the pilot of an aircraft with a coded radar beacon transponder, who desires to alert a ground radar facility, should squawk Mode 3/A, Code 7700/Emergency and Mode C altitude reporting and then immediately establish communications with the ATC facility.
Radar facilities are equipped so that Code 7700 normally triggers an alarm or special indicator at all control positions. Pilots should understand that they might not be within a radar coverage area. Therefore, they should continue squawking Code 7700 and establish radio communications as soon as possible.
Retrieved from ecfr.gov on July 20, 2026.