I've been listening to some ATC from some major commercial pilots and in every video where there's been some confusion about declaring an emergency they've used some terminology other than "mayday, mayday, mayday" (here's an example).

Given that how unmistakable saying the word "mayday" is three times in succession to people of different languages and accents, and that it's much quicker than saying "declaring an emergency, declaring an emergency, declaring an emergency", I'm trying to understand why the "mayday" terminology isn't universal. I can't come up with any situation where a triple mayday call won't be the clearest and quickest way to indicate an emergency situation, regardless of whether or not the controllers and pilots speak English or not?

Are there any good reason for not using triple mayday for declaring an emergency? Are there some ATC controllers that wouldn't know what it means? I just don't understand because it seems to be clearly understood every time whereas alternative often aren't, even with two native English speakers.

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    $\begingroup$ Per AIM 6-3-1(d), "the word MAYDAY commands radio silence on the frequency in use." If that's what I need, I'll say it. $\endgroup$
    – StephenS
    Commented Dec 26, 2019 at 18:07
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    $\begingroup$ Did you consider that it might be nothing more than a matter of practice? How many pilots ever have more than one occasion to declare an emergency in an entire career? Personally, while I've never had to declare an emergency, I think I'd be too busy flying to concentrate on using proper communication terminology :-) $\endgroup$
    – jamesqf
    Commented Dec 26, 2019 at 18:21
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    $\begingroup$ As a complete non-pilot, mayday would be the first word that would come to my mind a fast paced and panicked situation, just because it's so prevalent in popular culture. The "declaring an emergency" terminology is only something I learnt after listening to ATC videos. $\endgroup$
    – Clinton
    Commented Dec 27, 2019 at 0:45
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    $\begingroup$ In my very, very limited experience, what happens is that the aircraft is already talking to ATC and an 'issue' escalates to an urgency or emergency situation. Since there's already a conversation going on and the flight crew are concentrating on the 'aviate' and 'navigate' bits, actually saying the words 'mayday' or 'pan-pan' is a redundant distraction. I could be wrong, this is based on three or four situations I've been privy to. $\endgroup$ Commented Dec 27, 2019 at 0:45
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    $\begingroup$ @Clinton - The one incident I had, I was talking to ATC about an airframe issue and discussing my return to the field and my joining preferences. ATC asked me if I wanted to declare an emergency before I had thought about it - I was working the problem and concerned with getting down safe rather than exactly what terminology I used. When I've heard others in trouble, it's been ATC that have brought up the urgency/emergency thing because the flight crew have had their hands full with flying the aircraft. $\endgroup$ Commented Dec 27, 2019 at 0:55

4 Answers 4


I'm a controller, not a pilot, so I can only speak from my own perspective.

What we are taught in ATC school is that many pilots are reluctant to use the word mayday because they feel it might escalate a situation unnecessarily and potentially create a lot of paperwork. I guess, mentally, it seems like calling mayday is a significant, irreversible step which can be daunting to take. They might be afraid, assuming the situation goes well, that they have to explain why they decided to escalate the situation, get emergency services involved etc.

That's not really a resonable fear, though. In fact, as a controller, I would much prefer a pilot to call mayday as opposed to trying to make the situation seem less critical than it is. In an emergency, clear communication is absolutely essential. I've had several situations where pilots have had "minor technical issues" or an engine that is "a bit jumpy" or something like that, and it puts me in a really uncomfortable situation because I can't really tell how serious it is. And if I'm in doubt, I will just call the emergency services anyway. On the other hand, the one time I actually had someone call mayday, within 30 seconds, the firetrucks were on the move, all the runways were cleared and the aircraft in question was cleared to land. It's much easier to help you if you are clear about what you need!

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. This procedure, which is an international standard, is the single most effective means of alerting the controller to the need to give priority to the message that will follow.

Emergency Communications on SKYbrary

In the end, it is always up to the pilot(s) to decide what is the right thing to do. Every emergency situation is unique, and there isn't (and can't be) rules describing what exactly must be done in every single situation.

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    $\begingroup$ Is there any additional paperwork involved for either pilot or controller when an emergency is declared? I do think it's human nature to not want to make a mountain out of a molehill especially if they have to explain it later. $\endgroup$
    – TomMcW
    Commented Dec 26, 2019 at 16:51
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    $\begingroup$ @TomMcW Probably there is. Else ruthless pilots could declare an emergency just to get a priority landing to be home for dinner and then just say "oops, sorry". I definitely doubt this. $\endgroup$
    – PerlDuck
    Commented Dec 26, 2019 at 17:11
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    $\begingroup$ @TomMcW There is always paperwork involved after any kind of incident, but nothing major. At least from the ATC perspective, the paperwork is exactly the same whether a mayday is called or not. $\endgroup$ Commented Dec 26, 2019 at 18:49
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    $\begingroup$ @TomMcW - Insurance companies often ask about 'incidents' and I think that may act as a disincentive to call a pan-pan or mayday $\endgroup$ Commented Dec 27, 2019 at 0:58
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    $\begingroup$ There was a great wings seminar many years ago about controllers declaring emergencies when pilots are unwilling or too busy. I wish I could find the audio they played of a pilot that just replied "unable" to a couple of simple instructions (in icing conditions) followed by the controller calling 5 or 6 other airplanes in quick succession cancelling descent clearances or turning them out of the way. It was really moving. $\endgroup$ Commented Dec 27, 2019 at 3:36

Saying mayday or pan-pan is only recommended, and repeating it three times is merely preferable.

That statement applies to USA, and ICAO in general, by referencing both the AIM and AIP; and ICAO's Annex 10 Volume 2, respectively.

Let's begin with the basic (from the linked AIP):

A pilot who encounters a distress or urgency condition can obtain assistance simply by contacting the air traffic facility or other agency in whose area of responsibility the aircraft is operating, stating the nature of the difficulty, pilot's intentions and assistance desired. [emphasis added]

In the linked video, the pilot followed the above guideline: stating that he needs to land right away (difficulty), does not need vectors and is going for the runway visually (intentions), and wants the runway clear of planes (assistance).

The AIP then discusses ICAO's recommendation:

The initial communication, and if considered necessary, any subsequent transmissions by an aircraft in distress should begin with the signal MAYDAY, preferably repeated three times. The signal PAN-PAN should be used in the same manner for an urgency condition. [emphasis added]

Note that should is lesser than shall or must.

Now, from an FAA study, the following offers an insight into why the recommendation is sometimes not followed:

Occasionally, when things get really tense, our excitement level may be higher, and we may lend ourselves to slang or nonstandard terminologies. That's when communication goes out the window. I think sometimes ATC does not understand we need to divert or must declare an emergency, and they'd probably rather hear us say "Mayday."

The study was on Flight Language Experiences: Non-Native English-Speaking Controllers Communicating with Native English-Speaking Pilots.

This also answers that mayday is indeed globally understood.

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    $\begingroup$ Very good answer. The last quote especially is very relatable $\endgroup$ Commented Dec 26, 2019 at 18:50
  • $\begingroup$ @J.Hougaard: Thanks, and thanks for the earlier commenting asking for more information. $\endgroup$
    – user14897
    Commented Dec 26, 2019 at 21:29
  • $\begingroup$ It would seem to me as a non-pilot that in a stressful situation "mayday" would be the call I'd fall back on automatically, just as it's so ingrained as it's common in popular culture. "Declaring an emergency" seems like a phraseology that's trained, as I've never heard of it before watching ATC videos. Assuming it is trained wondering why it's trained over the more intuitive "mayday" call? $\endgroup$
    – Clinton
    Commented Dec 27, 2019 at 1:06
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    $\begingroup$ @Clinton It's not really a trained phraseology so much as just the pilot speaking naturally. "Mayday" is just a standardized phraseology for declaring an emergency. In normal speech, one would just talk about declaring an emergency. $\endgroup$
    – reirab
    Commented Dec 27, 2019 at 1:14

"Mayday, Mayday, Mayday" tells ATC (and everyone else on frequency) that you have an emergency, but it gives them exactly zero information about the nature of the emergency or what you need other than getting their attention and time on frequency. If you're in a portion of flight where you don't already have the attention of the controller, then adding "Mayday" or "Pan-Pan" calls to the beginning of your transmission helps to get you that immediate attention. However, if you already have their attention and other people aren't trying to talk on frequency, then it's not as necessary.

Furthermore, when quick communication is necessary and/or the pilot needs to be focusing on flying and navigating the aircraft rather than communicating (as is often the case in an emergency situation,) adding the "Mayday" calls to the beginning of your transmission even when you already have the controller's attention may go from merely unnecessary to actively unhelpful.

Of course, when you're in areas where English isn't the native language (or if English isn't your native language,) then sticking to the standard phraseology becomes more important, both for the sake of ATC and the other traffic on frequency. Even when all parties involved are fluent, significant differences in accents can make communication less clear, so using clearly-recognizable standard phraseology is more helpful for clear communication.

As far as the situation in the linked video, I would say that was more a case of ego than unclear communications. There's nothing particularly unclear about,

"We can't land on 22, we're breaking off the approach, and if you don't give us runway 31R, we're going to declare an emergency."

The situation wouldn't really have been made any more clear by adding "Pan-Pan, Pan-Pan, Pan-Pan," or "Mayday, Mayday, Mayday" to the beginning of it and everything they did say would still need to have been said. Once American 2 became aware of the crosswind problem on 22L, they quickly needed to change to 31R and they needed to communicate that as quickly as possible to Tower. Adding something to the beginning of the transmission would have just made it take longer to communicate and at a time when pilot workload would have been quite high preparing to change runways near the airport. The pilots needed to be spending their time talking to each other and focusing on flying and navigating the airplane, not on talking to Tower.

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    $\begingroup$ Saying "If ... we're going to declare an emergency" is actually not declaring an emergency. That's just a conditional promise. The ATC made that fact clear too. Only after the pilot continued with "we are declaring an emergency" it was clear. So adding 3x MAYDAY in the beginning would have made a big difference. $\endgroup$
    – Curd
    Commented Dec 27, 2019 at 11:33
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    $\begingroup$ @Curd True, the pilot could have just gone ahead and declared an emergency in the first call. They decided to try less escalation first so that it wasn't just totally out of the blue and the controller had a chance to work with them without having to escalate to an emergency. When that didn't work, then they immediately declared an emergency. Regardless, I would still say that their statements were 100% clear and unambiguous the entire time, while proving the information that ATC needed and trying to maintain brevity so that they could focus on flying the airplane during a high workload. $\endgroup$
    – reirab
    Commented Dec 27, 2019 at 11:36
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    $\begingroup$ @reirab: That sounds like the intention was to say "This plane is going to land on runway 31R. Expect to apply whatever level of emergency handling will be needed to make runway 31R ready to accept it." $\endgroup$
    – supercat
    Commented Dec 27, 2019 at 17:26
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    $\begingroup$ If there's a way to communicate something using standard phraseology, then communicating using non-standard phraseology is definitely less clear. As the recording illustrates plainly the controller didn't actually understand whether it was an emergency, Also what if the "don't" in your quote had been clipped and the controller understood it to mean "don't vector us for 31R"? Definitely clearer to say "UNABLE. PAN PAN PAN American 2. REQUIRE 31R." $\endgroup$
    – Hugh
    Commented Dec 28, 2019 at 5:27
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    $\begingroup$ The first time I heard the recording, I thought after the approach the pilot withdrew the emergency declaration, but he actually reissued it. That's about as unclear as you can get. $\endgroup$
    – Hugh
    Commented Dec 28, 2019 at 5:27

Mayday is a protocol for "breaking in unannounced" you might say, or for broadcasting in the clear on an open frequency to whoever might hear you. So if you are flying around VFR and need to broadcast that your engine just quit, or are in an airliner on the North Atlantic Tracks out of ground based VHF and radar coverage, you use Mayday for sure.

When you are already in routine communication with ATC with a transponder code assigned and are an identified target on someone's radar display, it's not really necessary. You can say Mayday, but ATC just needs to hear the word "emergency", and even if you don't do that, setting the 7700 transponder code is sufficient.

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    $\begingroup$ That's simply not true. Mayday is certainly supposed to be used when talking to ATC. And 7600 is a code for com fail, not emergency. $\endgroup$ Commented Dec 26, 2019 at 16:02
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    $\begingroup$ @J.Hougaard I learned this mnemonic: "75 - man with a knife, 76 - I need my radio fixed, 77 - I'm falling from heaven". $\endgroup$
    – PerlDuck
    Commented Dec 26, 2019 at 16:11
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    $\begingroup$ @MichaelHall Not necessarily. But it is easier to choose the right service to provide when pilots are clear about what they need $\endgroup$ Commented Dec 26, 2019 at 18:48
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    $\begingroup$ en.wikipedia.org/wiki/Avianca_Flight_52 $\endgroup$ Commented Dec 26, 2019 at 19:56
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    $\begingroup$ No obviously I would not treat someone saying "emergency fuel" differently than someone saying "mayday". But the former is not correct phraseology, the latter is. $\endgroup$ Commented Dec 26, 2019 at 19:57

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