Definition
An ATC instruction directing the pilot to set the transponder to code 7700, the universal emergency code, which alerts every air traffic control facility receiving the signal that the aircraft is in distress.
Plain English
The controller is telling you to set 7700 on your transponder so that everyone on radar instantly sees you have an emergency.
Context Anchor
Seen in transponder and ATC phraseology, especially during emergency communications or radar services.
Derivation
‘Squawk’ comes from World War II IFF (Identification Friend or Foe) systems nicknamed ‘Parrot,’ so transmitting a code became ‘squawking.’ ‘Mayday’ comes from the French ‘m’aidez’ meaning ‘help me,’ adopted internationally as the spoken distress call. Combined, the phrase means ‘send the distress signal.’
Why Pilots Care
Activates immediate priority handling and alerts all nearby facilities without further radio calls.
Intuition Check
“Squawk” does not mean make a voice call here; it means set the transponder. “Mayday” does not mean the calendar date; it means the aircraft is in distress and needs urgent help.
Example Sentence 1
After the engine failure, ATC instructed, ‘Squawk Mayday,’ and the pilot dialed 7700 into the transponder.
Example Sentence 2
The controller told the pilot in distress to squawk Mayday on the transponder.