Glossary

turboprop charter planes - Pilatus PC12

Mayday

Mayday is an emergency word used around the world as a distress signal. If commercial or private flights are in danger, the pilot will issue a mayday distress signal over radio communications. It’s typically used three times in a row to prevent being mistaken for a discussion about the term mayday, especially during noisy conditions.

The History of the Mayday Call

SOS using Morse code was used as a distress signal originally, but the antiquated term was replaced in the 1920s.

Originating in 1923, the term mayday was used by a senior radio officer at an airport in London. The officer was asked to think of a word that would be easily understood and indicate distress in an emergency. Since the majority of the commercial and private flights during that time ran between London and Paris, the officer used a French word for inspiration. ‘M’aider’ in French, which sounds similar to mayday, means “come and help me.”

By 1927 the International Radiotelegraph Convention in Washington replaced SOS with Mayday. The term has been used fully among the aviation industry ever since.

It’s in the Call

During an emergency situation, pilots are instructed to include the following information in their mayday call:

  • Name of station being addressed
  • Aircraft call sign and type
  • Nature of emergency
  • Current weather conditions
  • Pilot’s intentions/requests
  • Present location or last known location during which time
  • Flight level/altitude
  • Remaining fuel level (in minutes)
  • Number of passengers