Pilots frequently use mayday to signal emergencies in popular entertainment, but have you ever wondered what it actually means?
Mayday is derived from a French word, and it means “help” or “help me”.
Pilots say mayday three times during emergency situations to alert Air Traffic Control and request guidance and assistance from them.
Although mayday is the most famous emergency call sign, there are several others like ‘pan-pan’ that pilots also use in different emergency circumstances.
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What Mayday Means in Aviation
Mayday is used to signal a distress call on radio, and it’s universally recognized for this purpose.
People on board ships and planes use mayday to signal life-threatening emergencies, but it’s also used for other situations.
In aviation, a distress call will include mayday repeated three times, after which the distressed party provides relevant information. Mayday calls may even be sent by one aircraft on behalf of another one.
The Origin of the Mayday Call
The mayday call was developed in the 1920s, and it was first used by Frederick Stanely Mockford.
Mockford was a senior radio officer at the now defunct London Croydon airport.
Senior officers at Croydon airport told Mockford that they needed a call that could be easily understood to both pilots and ground staff during emergencies.
Mockford derived mayday from a French term: ‘venez m’aider’, which translates to ‘help me’.
What Heavy Mayday Means
Heavy mayday is not an official term, although it is used by many pilots to indicate extreme difficulties.
Pilots conventionally use heavy mayday when their plane is close to crashing or suffering other extreme failure.
The “heavy” in heavy mayday is only used for emphasis and does not have any technical meaning. So it’s just an unofficial expression.
For example, United Airlines Flight 328 made an emergency landing at Denver airport in 2021.
The pilot was heard saying “Mayday, mayday, heavy mayday” to Air Traffic Control while stopping his plane from crashing.
The use of ‘heavy’ was only intended to emphasize the degree of danger the plane was in.
Why a Pilot Might Say Mayday
Pilots say mayday when their aircraft is experiencing an incident, and they need to inform the authorities.
Pilots also provide incident-related information and identification of themselves and their aircraft during mayday calls to receive better assistance.
Specific situations where pilots would say mayday include during engine failure, hydraulic failure, electrical fires, or malfunctioning components.
Providing this information to Air Traffic Control makes it easier for them to assist the pilots.
In a majority of cases, pilots will only issue mayday signals when their aircraft is under threat of crashing or other severe incidents.
Other signals are used when an incident occurs but is not dangerous enough to threaten crashing the aircraft or causing loss of life.
Why Pilots Say Mayday Three Times
Pilots conventionally say mayday thrice for clarity and to ensure the message is heard.
Another reason is to prevent confusion between a mayday call and a message about a mayday call.
If mayday calls aren’t immediately recognized and assistance is immediately provided, there could be loss of life or damage to the aircraft.
Pilots have to quickly and effectively complete mayday calls to ensure their message is unambiguously understood.
Saying mayday thrice has been found to be the best way to ensure the message is clearly understood.
How Pilots Say the Mayday Call Correctly
Pilots use the following convention for making mayday calls during emergency situations. They should include as many of these elements as they can, and in the stated order, but it is not strictly required.
- Mayday mayday mayday
- Name of station
- Aircraft identification
- Information about the emergency
- Weather conditions
- Pilot intentions
- Current or previous position and trajectory
- Altitude of plane
- Remaining fuel in minutes
- Number of passengers
- Any other relevant information
After providing the above information, pilots receive instructions and advice from Air Traffic Control.
Pilots are permitted to ask questions or clarify instructions from Air Traffic Control.
Pilots are also required to not change frequencies or contact other ground stations unless absolutely necessary.
Other Urgent Calls Pilots Use
Although mayday is the most known emergency call, the following three are also used under different circumstances.
Pan-pan is derived from the French “panne”, meaning breakdown.
It is used for urgent situations like mechanical failures or medical problems that aren’t life-threatening.
So, pan-pan would not be used for an aircraft that is about to crash.
It’s only used for emergencies that won’t potentially crash an aircraft or cause serious loss of life.
- Declaring Emergency
Sometimes pilots declare emergency instead of calling ‘mayday’, but it is not an official term.
The international Civil Aviation Organization even recommended using ‘pan-pan’ and ‘mayday’ instead of declaring an emergency.
There have been many cases of confusion caused by pilots declaring emergencies instead of using “pan-pan” or “mayday”, so it’s heavily advised against.
In aviation, the definition of wilco is that the pilot understands the instructions and “will comply”.
This is different to roger, which simply means that a pilot has acknowledged what has been said yet has not given any confirmation that they will comply.
The more complex the information a pilot receives, the more the need for the pilot to report back what was said to them on their aviation radio to make it explicitly clear that they understood what was said.
Wilco, therefore, is usually used by pilots as not just a standalone callsign, but as part of a longer communication response.
- Seelonce Mayday
Seelonce mayday is used to request that the channel only be used for aircraft involved in the mayday incident.
When seelonce mayday is issued, a channel won’t be used for normal working air traffic until the case is resolved.
Seelonce mayday is rarely used these days, but it remains a valid emergency signal.
- Mayday is an emergency signal that pilots use when their aircraft is in imminent danger.
- The term was developed in the 20th century, and it is derived from the French word for help.
- Pilots use mayday when their aircraft is in danger of crashing, or is otherwise threatened by grave or imminent danger.
Helen Krasner holds a PPL(A), with 15 years experience flying fixed-wing aircraft; a PPL(H), with 13 years experience flying helicopters; and a CPL(H), Helicopter Instructor Rating, with 12 years working as a helicopter instructor.
Helen is an accomplished aviation writer with 12 years of experience, having authored several books and published numerous articles while also serving as the Editor of the BWPA (British Women Pilots Association) newsletter, with her excellent work having been recognized with her nomination of the “Aviation Journalist of the Year” award.
Helen has won the “Dawn to Dusk” International Flying Competition, along with the best all-female competitors, three times with her copilot.