Friday, June 15, 2012

Mayday, the International Distress Call

This is the kind of helicopter I was flying when I had to declare a Mayday over Hackensack, NJ
Photo by Raimond Spekking

When I was flying I was forced to use the international distress call “Mayday” three times; in two of these incidents I actually declared a mayday, the third event happened so fast that I was on the ground before I was able to make the Mayday declaration.

Two of these events were in helicopters and the third was a conventional airplane. Two of them were related to fuel problems in the helicopter that caused by an infestation of bacteria in the fuel supply. The third was in a brand new airplane that had a leak in the engine that caused all the oil to run out causing the engine seize, and partially come apart.

The word Mayday is derived from the French phrase ‘venez m’aider’ meaning come help me. In a real emergency the word is repeated three times, “Mayday, Mayday, Mayday” with the call sign of the aircraft following along with information about the nature of the emergency and the people aboard the plane. A mayday is always used to signal a life-threatening emergency usually involving aircraft, boats or ships.

The use of mayday as an emergency code word is used all over the world as a distress signal in any voice procedure radio communication. It's only is use to signal a life-threatening emergency used by many groups including police forces, pilots, firefighters and other transportation organizations. Mayday is always repeated three times in a row “Mayday, Mayday, Mayday” so that it is not mistaken for some other similar sounding word when given under poor radio transmission conditions. It is also used to distinguish an actual Mayday call from any other messages that may relate to a Mayday call.

A typical mayday calls sounds like this, “Mayday Mayday Mayday Teterboro Tower this is Helicopter 44 Charlie Bravo, this is helicopter 44 Charlie Bravo, this is helicopter 44 Charlie Brave with one person aboard; we’re going down, we’re going down, we’re going down! Over Hackensack New Jersey at 1500 feet hitting 200°, have picked a site to attempt an autorotation landing” The message ends; “Mayday 44 Charlie Bravo, over.”  This is an actual Mayday call I declared during the summer of 1978.

In an aircraft this is usually broadcast on 121.5 MHz or 243.0 MHz. In a boat or ship it is usually broadcast on a marine channel at 2182 kHz or on High Frequency radio channel 16 (156.8 MHz). This call is roughly the voice equivalent of an SOS, or a telephone call to 911.

Making a hoax Mayday call is a crime in most countries and in the United States it is a federal offense punishable by up to six years in jail and/or a $250,000 fine. Anyone may legally make a Mayday call to summon help in any real emergency without having to hold a license as a radio operator.

The use of mayday is a distress signal goes back to the early days of aviation where it was developed in England in the early 1920s at the then London airport at Croydon. It was originally used between Croydon and the airport at Paris, France, Le Bourget. The use of mayday is an international distress call spread from there to encompass the entire world.


Personal experience as a pilot

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