The pilots sent out a Pan Pan Pan, signaling that the aircraft was experiencing a problem, but there was no immediate danger. At the time, they believed there was an issue with the air conditioning system and were unaware of the rapidly intensifying fire in the ceiling.
The radiotelephony message PAN-PAN is the international standard urgency signal that someone aboard a boat, ship, aircraft, or other vehicle uses to declare that they need help and that the situation is urgent, but for the time being, does not pose an immediate danger to anyone's life or to the vessel itself.
Pan-Pan, short for “possible assistance needed,” is used to communicate an urgent, but not emergency, situation over VHF radio, in the case of aviation, to air traffic control. Examples could include a recreational pilot getting lost, or perhaps needing to climb to a higher altitude to sort a problem out.
Distress communications have absolute priority over all other communications, and the word MAYDAY commands radio silence on the frequency in use. Urgency communications have priority over all other communications except distress, and the word PAN-PAN warns other stations not to interfere with urgency transmissions.
Pan-Pan is derived from the French word "panne", which means failure or breakdown. Pan-Pan most often refers to a mechanical failure or breakdown of some kind.
Convention requires the word be repeated three times in a row during the initial emergency declaration ("Mayday mayday mayday") to prevent it being mistaken for some similar-sounding phrase under noisy conditions, and to distinguish an actual mayday call from a message about a mayday call.
Mayday got its start as an international distress call in 1923. It was made official in 1948. It was the idea of Frederick Mockford, who was a senior radio officer at Croydon Airport in London. He came up with the idea for “mayday" because it sounded like the French word m'aider, which means “help me."
A pilot who encounters a Distress condition should declare an emergency by beginning the initial communication with the word “Mayday,” preferably repeated three times.
Mayday: it's the international signal for an emergency made by planes and boats which use radio communications, which was recently used on Qantas flight QF144 from Auckland to Sydney, which ended up landing safely.
Squawking 7700 in an emergency
The most well know of these is the code 7700. This is used to indicate an emergency of any kind. A pilot will enter this when in an emergency situation - either instructed by ATC after declaring an emergency or without communication if there is no time.
Mayday procedure
“Mayday, Mayday, Mayday” “This is [vessel name and/or call sign if you have one]” (spoken three times) “Mayday [vessel name and/or call sign if you have one]” “My position is ... [Details of the ship's position]” “My vessel is ... [Nature of distress and assistance required is identified]” “I have ...
Owing to the difficulty of distinguishing the letter “S” by telephone, the international distress signal “S.O.S.” will give place to the words “May-day”, the phonetic equivalent of “M'aidez”, the French for “Help me.” —”New Air Distress Signal,” The Times [London], 2 Feb. 1923.
Pilots believing themselves to be facing an emergency situation should declare an emergency as soon as possible and cancel it later if the situation allows. The correct method of communicating this information to ATC is by using the prefix “MAYDAY, MAYDAY, MAYDAY” or “PAN PAN, PAN PAN, PAN PAN” as appropriate.
Pilots, also called captains, and co-pilots are essential for safe and timely air travel. Both pilots and co-pilots can help fly an airplane, and they typically have very similar responsibilities.
FISH-SAFE: The mayday distress call – Where it originated, when to use it, and when not to. Before the mayday distress call existed, that is before the radio as we know it was in use, telegraph operators used the Morse Code signal — three dots, three dashes, three dots — to communicate distress.
A Man Overboard (MOB) situation is one of the most traumatic events on-board any vessel. Nevertheless, it is not always a MAYDAY situation. It is not always a PAN PAN situation either. Sometimes, it is not even an emergency!
So they took "Roger" from the U.S. phonetic alphabet. (In 1957, the English phonetic alphabet changed the R to "Romeo," but by that time, "Roger" was deeply embedded in the minds of pilots.) So, in short, "Roger" means "r" which stands for "received." The word "Roger" means nothing more.
Yes, it is correct to use MAYDAY or PAN PAN PAN on the ground. In recurrent training we are often reminded that in the case of a rejected takeoff in a foreign country it is important to use MAYDAY or PAN PAN PAN on the ground to avoid any confusion due to language difficulties.
The phrase "five by five" can be used informally to mean "good signal strength" or "loud and clear". An early example of this phrase was in 1946, recounting a wartime conversation. The phrase was used in 1954 in the novel The Blackboard Jungle.
Affirm: Contrary to popular belief, pilots do not say “affirmative” when they mean yes – the correct term is affirm, pronounced “AY-firm.”
Make shortly after landing, once the engine noise has subsided. “Ladies and gentlemen, [Airline Name] welcomes you to [city]. The local time is [time]. For your safety and the safety of those around you, please remain seated with your seat belt fastened and keep the aisle(s) clear until we are parked at the gate.
Pan-Pan calls (pronounced "pahn-pahn") are used for urgent situations that are not life-threatening such as your pleasure craft is broken down, out of gas, or lost in fog.
Although the international Mayday distress signal for aircraft and boats was invented by an English man it comes from the French expression “Venez m'aider”, meaning “come and help me”.
The expression “Save Our Ship” was probably coined by sailors to signal for help from a vessel in distress.
A 'mayday' call indicates an aircraft is in grave and imminent danger and requires immediate assistance.