Mayday
Mayday is the international radiotelephony distress signal, used when an aircraft is in a state of grave and imminent danger requiring immediate assistance. It is derived from the French phrase “m’aider” (help me). A Mayday call takes absolute priority over all other radio communications.
Mayday Call Format
Standard format: “MAYDAY MAYDAY MAYDAY, [facility name], [aircraft callsign], [nature of distress], [intentions], [position], [altitude], [pilot qualification, e.g., student solo], [persons on board], [fuel endurance], [any other relevant information].” If time is critical, transmit what you can — even “MAYDAY [callsign] engine failure” is enough to initiate a response.
Mayday vs. Pan Pan
- MAYDAY: Grave and imminent danger — immediate assistance required; engine failure, fire, structural damage, medical emergency
- PAN PAN: Urgent condition — assistance may be required but not immediately; lost, passenger medical issue (not life-threatening), fuel running low
Mayday Frequency
Transmit on the frequency currently in use first. If no response or you have already lost contact with ATC, transmit on 121.5 MHz (international distress frequency) — this is monitored by all ATC facilities, many aircraft, and aeronautical rescue coordination centres.
On the TC Written Exam
Know the Mayday call format, the distinction between Mayday and Pan Pan, and the international distress frequency (121.5 MHz).
Related Terms
See also: Pan Pan, ELT, Alerting Service.