On January 23, 2015, I flew from Buenos Aires, Argentina (SAEZ) to Santiago, Chile (SCEL). It was a very comfortable night flight in a Boeing 787 Dreamliner of LAN airlines, though it was delayed.

During the descent and a pronounced turn to the left at approximately 4,000ft above the Andes Mountains, I saw through the window a wood fire in the middle of darkness with some shadows around. Then a brilliant white light blinking: three short flashes, three long flashes, three short flashes. I thought: Wow! That antenna blinked like an SOS signal!

One second after the first sequence, again: three short, three long, three short. Then I unfastened the security belt to run and tell the closest flight attendant: Sir! There is an SOS signal there, and he started to give attention to it.

After a successful landing on runway 17 L/R, I asked the flight attendant if they have a procedure to handle this kind of sightings. He told me there is no such procedure and that I should go to inform the civil protection office.

Due to a lack of enough time before the next flight, I asked a security officer to inform the civil protection office, giving her the flight number, exact time of the sighting and after calling the person in charge, she asked me for my name and details about the sighting. Trying to be descriptive, I clearly told her all details before running to catch the next flight and almost losing it.

How should passengers report SOS signal sightings?

P.S. The place of sighting was somewhere over the mountains in the west of Los Andes in Chile.

  • 10
    $\begingroup$ You did exactly what I would have done as well. Inform the cabin crew. In turn, they can inform the flight crew who will notify ATC. ATC has a direct line to search and rescue. $\endgroup$ Commented Jun 3, 2017 at 6:49
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    $\begingroup$ How is this opinion based? There are laid down regulations and procedures for dealing with exactly this situation. $\endgroup$
    – Simon
    Commented Jun 3, 2017 at 8:07
  • 17
    $\begingroup$ Did you eventually find out what happened that day? We're curious. ;-) $\endgroup$
    – PerlDuck
    Commented Jun 3, 2017 at 8:59
  • 2
    $\begingroup$ @Simon there are procedures for how flight crews should react. As far as I know, there are no procedures for how passengers should react. $\endgroup$ Commented Jun 3, 2017 at 9:45
  • 8
    $\begingroup$ thank you for all your horizon expanding comments :D @PerlDuck on next day i tried to contact the civil protection office and googled for news about alpinists in chile without finding something after some days :/ i still having curiosity after two years and would like to know what happened? $\endgroup$
    – ncomputers
    Commented Jun 3, 2017 at 16:07

3 Answers 3


There is a procedure, at least for the aircraft crew.

It is appropriate for a flight crew to transmit a "pan pan" or even a "mayday relay" so a passenger should immediately inform the senior cabin crew member, usually by asking to speak to the "purser". SOS is an internationally recognised distress signal. If the purser did not act upon it, I would politely, but assertively request that they inform the captain since these procedures are part of standard pilot training and flight crews are required to respond to potentially life threatening situations.

Reporting emergencies or urgent situations is not restricted to the aircraft itself. It can, and should be used, where any threat to life or safety is real or possible. ATC in turn can contact the appropriate local resources depending on the situation.

An example would be if I was flying and witnessed a fire or perhaps a road crash and emergency services were not already in attendance, I would not hesitate to contact ATC and be prepared to offer assistance if possible, for example relaying position or exact circumstances.

You did the right thing. Perhaps you could have been a bit more assertive at the time, when the cabin crew member incorrectly told you that there is no procedure, since minutes can count.

  • 3
    $\begingroup$ "Pan pan" seems to give privileges to the cabin crew, more attention and more resources (runway, airspace...). I see it as a right granted to the crew, not an obligation for the crew to report something to ATC. For the "mayday relay" which seems more obligation related, is it applicable to a flight attendant? By which regulation? In which airlines? $\endgroup$
    – mins
    Commented Jun 3, 2017 at 10:58
  • $\begingroup$ @mins What is the cabin crew going to do with a longer runway or less airspace restrictions? :P $\endgroup$
    – reirab
    Commented Jun 4, 2017 at 12:18
  • $\begingroup$ @reirab: My question is how the mayday relay would be known by the flight attendant and force them to transmit the OP observation to the pilot. My comment about the pan-pan was that it didn't look like an obligation to the flight crew (and I wrote cabin crew instead). $\endgroup$
    – mins
    Commented Jun 4, 2017 at 14:02
  • $\begingroup$ @mins Yeah, I figured you meant flight crew rather than cabin crew for that part. :) $\endgroup$
    – reirab
    Commented Jun 4, 2017 at 19:10
  • $\begingroup$ @mins. I don't believe that a passenger could "force" a flight attendant to do anything. As I say, if I was in this situation, I would politely but assertively ask them to inform the captain. I know this will vary a lot. I am a typical alpha male and I know how to be very assertive without being threatening but the first part of this chain is, as you correctly say, not mandated. $\endgroup$
    – Simon
    Commented Jun 9, 2017 at 7:18

How should passengers report SOS signal sightings?

You did it right, the head of the cabin crew must inform the captain, as you asked for, the captain must inform ATC and ATC the rescue organization when the information is credible. These matters are highly subject to judgment at any stage of the reporting chain, and it would be interesting to have a view from a legal person about precedents.

I asked the flight attendant if they have a procedure to handle this kind of sightings. He told me there is no such procedure and that I should go to inform the civil protection office.

That's probably wrong, the attendant should report this to the captain. Not doing that is probably a professional misconduct. As for the informed captain not complying, they would be exposed to legal action if it was an actual distress situation (see below).

In addition to this crew obligation, anybody can be, to a variable extent depending on the jurisdiction, liable to a duty to rescue. An SOS signal is possibly a sign of distress, it triggers this duty to rescue.

1. ICAO Chicago Convention

The ICAO Chicago Convention is an international treaty, a law for the signatories, implemented in the State legal system by the aeronautical information publication.

The Convention includes Annex 12, dealing with Search And Rescue and its article 5.7 providing a guidance for managing the interception of distress signals. (In aviation terms, the pilot-in-command is the person among the flight crew, legally responsible for the flight, like the captain of a ship):

5.7 Procedures for a pilot-in-command intercepting a distress transmission

Whenever a distress transmission is intercepted by a pilot-in-command of an aircraft, the pilot shall, if feasible:

a) acknowledge the distress transmission;

b) record the position of the craft in distress if given;

c) take a bearing on the transmission;

d) inform the appropriate rescue coordination centre or air traffic services unit of the distress transmission, giving all available information; and

e) at the pilot’s discretion, while awaiting instructions, proceed to the position given in the transmission.

It should be noted this article is connoted to rescuing ships/aircraft, which was the concern at the time it was written, but is expressed in such a broad way it becomes applicable to any distress message.

2. Example: Implementation in the French Air Regulations

In the French AIP for La Réunion and Mayotte Islands, those articles are relevant:

GEN Rules to be observed by aircraft commanders

1) Pilots who witness a situation in which people are endangered:
When an aircraft commander of an aircraft witnesses a situation in which people are endangered, he shall proceed as indicated below unless it is impossible to do so or, based on the prevailing circumstances, he considers it is unnecessary to do so: [...] notify or have someone notify, as appropriate:
- the area control center (ACC), which shall in its turn notify the ARSC [...]
2) Informed of a:
a) distress message or signal When an aircraft commander intercepts a distress message or signal, or is informed by any means, he must proceed as follows in compliance with applicable telecommunications procedures [...]
b) request for assistance by message or visual signal: When an aircraft commander intercepts a request for assistance by message or by a visual signal, or learns of such a request from any source,he shall notify the appropriate control or search and rescue unit as soon as possible [...]

3. Civil and/or criminal laws

At the State level (for an aircraft this is the country of registration), there are civil and/or criminal laws related to assistance: If someone asks for assistance when in danger, and a person denies it without a good reason, the latter is liable of failure "to assist a person in danger" or to the "duty to rescue". The idea is someone in great distress has a right to be rescued which automatically give others obligations to not abandon them.

In many countries these obligations are relevant of civil code, meaning one can be required to pay damages, but there is no criminal law associated. In some countries, this is a criminal law, e.g. in France not trying to help someone in imminent danger, and when this is possible without endangering oneself, can be punished of a five-year prison sentence. This would apply to any person, witnesses, cabin crew and cockpit crew, ATC, etc.


An important immediate action for a passenger is to note the exact time they saw the distress signal (or start a running stopwatch on a cellphone to keep track of elapsed time) and to note the direction relative to the airplane fuselage. If you can note another direction and time a couple of minutes later, so much the better. With this information and the radar or ADS-B records, search & rescue teams have a much better chance of determining the location.

Unfortunately by the time you've gotten a flight attendant's attention and they've informed the flight crew (if they're even willing to do so) the spot on the ground will probably be out of view, so without a pretty good estimate of the time you saw it the uncertainty in the location will be many tens of km - next to useless for search & rescue purposes.


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