mayday

Mayday is an international radiotelephony distress signal used to indicate a life-threatening emergency requiring immediate assistance. It is spoken three times in a row at the start of a message to alert all receiving stations that grave danger is present and that priority handling is required.

Origin and usage

The term was coined in 1923 by Frederick Stanley Mockford, a senior radio officer at Croydon Airport in London. He chose “Mayday” from the French phrase m’aidez, meaning “help me,” because it was easily understood by international pilots and ground personnel. Mayday is reserved for situations of grave and imminent danger, such as a aircraft in distress or a vessel in trouble. The initial Mayday transmission typically identifies the caller (ship or aircraft), its position or last known position, the nature of the emergency, the number of people on board, and the type of assistance required, followed by instructions from air traffic control or coast guard.

Priority and related procedures

When a Mayday is declared, all stations hearing the call must give it immediate attention and provide whatever assistance is available, while other traffic yields. If the situation is urgent but not immediately life-threatening, the term Pan-Pan is used. For safety-related messages that do not involve an emergency, the word Sécurité is used.

Regulatory framework

Mayday is defined in international radiocommunication conventions and is part of the distress procedures used in maritime and aviation contexts. It is transmitted on designated distress frequencies and channels, with procedures coordinated by national authorities and international bodies.

Other uses

In popular culture, Mayday is also used as a title or motif in films, television programs, and songs, often conveying themes of danger or urgent trouble. In standard practice, however, it remains the formal distress signal for life-threatening emergencies.