Skip to main content
Planned maintenance impacting Stack Overflow and all Stack Exchange sites is scheduled for Monday, September 16, 2024, 5:00 PM-10:00 PM EDT (Monday, September 16, 21:00 UTC- Tuesday, September 17, 2:00 UTC). The email/password authentication method will be unavailable for logging in and registering. Read more here
163 votes

Why do airplanes use MAYDAY when in danger but ships send SOS?

The difference here isn't between ships and aircraft: it's between Morse code and voice. The SOS signal is only for Morse code. It's short, easy to send, and easy to recognise. But it's not as ...
Dan Hulme's user avatar
  • 12.7k
119 votes
Accepted

How do civilian pilots and ATC verify that other people on the radio are who they claim to be?

This is a reasonable question, and to an outside the simple answer of We don't / can't might seem a little bit jarring. After-all, we live in a time of hacking, terrorism and so on and I can ...
Dan's user avatar
  • 9,368
97 votes
Accepted

How was I able to just plug in my headphones and listen to ATC and pilot chatter?

This is a feature offered on some United Airlines aircraft and flights. It's an interesting way to hear what's going on in the cockpit. You can find lots of information by searching for United channel ...
Greg Hewgill's user avatar
  • 9,182
70 votes

Is it acceptable to abbreviate “Foxtrot” to “Fox”?

Simply put: no, it is not ok to abbreviate the phonetic alphabet. The reason the phonetic alphabet is used in aviation is to make communications as clear as possible with minimum chances for ...
Jpe61's user avatar
  • 30k
66 votes
Accepted

Is it OK to greet ATC?

It is not part of the standard phraseology by any means, but it is fairly common, as is a very quick pleasantry when changing frequency. [station name], Good morning, G-ABCD, [request] and G-...
Jamiec's user avatar
  • 35.2k
62 votes

Why does the ICAO alphabet use "Charlie" for C?

Hard C sounds too much like K. Ch (Charlie) will not be confused with K (Kilo). And soft C sounds too much like S (Sierra).
CrossRoads's user avatar
  • 8,795
60 votes
Accepted

How does an Airbus aircraft connect to the Internet?

There are three different ways that aircraft can give internet access to its passengers, which will most likely be on at around 38,000 feet. First off, to have Inflight wifi, there needs to be a ...
SharkyPanda's user avatar
57 votes

Why do military pilots report "gear down" during their traffic calls?

Other answers mention "it's the rules" without specifying why the rules are what they are. Civilian airplanes are for the most part assumed to be in proper working order after a flight, ...
dotancohen's user avatar
  • 6,387
55 votes

Why do we say certain things three times (e.g., "Mayday, Mayday, Mayday"), rather than two or four?

Yep, the critical commands are repeated 3 times. This ensures there is ABSOLUTELY zero doubt in anyone's mind (especially on a big crew airplane) of what needs to be done in a critical situation. It ...
Scotty's user avatar
  • 511
53 votes
Accepted

What does ATC do during "slow" times?

Admin stuff, emails, chat with a colleague if you are not alone on shift, read up on (ever changing) procedures, eat, read a book, make sure the coffee machine works, meditate, watch TV. Anything goes,...
60levelchange's user avatar
51 votes
Accepted

Callsign includes the term 'with Kilo' ; What does that signify?

What that probably means is that the pilot is reporting that they have ATIS information kilo. Automatic Terminal Information Service (ATIS) is a radio broadcast on a specific frequency (often a local ...
GdD's user avatar
  • 54.2k
50 votes

What is your responsibility when a distraught pilot is on frequency?

On frequency, if control is responding to the distressed aircraft you should stay quiet and let them work the problem. This would not be a great time to ask for flight following or traffic advisories ...
Dave's user avatar
  • 102k
50 votes
Accepted

Should I contact ATC if I don't have a transponder?

Every US controller I've ever heard from says they'd prefer to be talking to every aircraft in their airspace, period. This lets them know your intentions and allows them to move you around if needed, ...
StephenS's user avatar
  • 27.8k
48 votes
Accepted

What kind of assistance can another aircraft provide to an incapacitated pilot?

This is speculative and I haven't looked at the links you gave, but I can think of a few things: Having another aircraft there gives ATC a way to gather information that they otherwise couldn't. For ...
Pondlife's user avatar
  • 71.9k
44 votes

Is it OK to greet ATC?

Technically you are not suppose to and for the greatest safety, internationally recognized vocabulary should always be used. However, I have noticed most heavy pilots and many controllers do a ...
jwzumwalt's user avatar
  • 11.5k
43 votes

How often does a pilot ask ATC for a repeat?

How often is hard to quantify, but in general I would suggest the answer is all the time. ATC is there to help you, as a service to you as a pilot. Sometimes out of necessity things are said quickly ...
Jamiec's user avatar
  • 35.2k
41 votes

What is meant by "Fox Two"?

Fox codes are used by NATO military aircraft to designate a release of an air-to-air munition, generally missiles. Fox One is a semi-active radar guided missile, for example the AIM-7 Sparrow. This ...
Benson_YoureFired's user avatar
40 votes

Why don't airports use different radio frequencies/channels for each plane to prevent communications from interfering with each other?

Because it is actually critically important that pilots all hear what is going on around them. In a perfect world, ATC could act as the go-between for everything. But in reality there are times when ...
manassehkatz-Moving 2 Codidact's user avatar
39 votes

How was I able to just plug in my headphones and listen to ATC and pilot chatter?

ATC and aircraft communications (at least in the US) are not restricted for receiving. Anyone can purchase (or make) an "Air band" receiver (or scanner radio) tunable through (roughly) 118-140 MHz and ...
The Beltway's user avatar
38 votes
Accepted

Why do we say certain things three times (e.g., "Mayday, Mayday, Mayday"), rather than two or four?

Procedure calls for the mayday distress signal to be said three times in a row so that it won't be mistaken for another word or phrase that sounds similar under noisy conditions. The use of Mayday ...
Clint Kearns's user avatar
37 votes
Accepted

What is your responsibility when a distraught pilot is on frequency?

Do not respond to irrelevant chatter on aviation frequencies. There are already way too many people who think it is ok to chit chat and joke on the radio while they are flying. Not only does this ...
Tyler Durden's user avatar
  • 13.3k
37 votes

When told "call sign only" in a frequency change, how to transmit it?

You always start a communication with the intended receiver, so in this case it would be London Approach, BAW211. What the controller is telling BAW211 is that London Approach has the relevant details ...
GdD's user avatar
  • 54.2k
36 votes
Accepted

Are “Kennedy Steve’s” various jokes allowed in ATC communications?

(US-based answer) Yes, it's legal. Yes, everyone - including pilots - is held to the same standard of professionalism. And there are no real consequences for anyone (usually). The simple fact is that ...
Pondlife's user avatar
  • 71.9k
36 votes
Accepted

Why doesn’t ACARS just use HF if it has better range than VHF?

The main concern is that radio spectrum is a shared resource, meaning that while you’re using it, nobody else within the range of your transmission can use it too. That means you always want to use a ...
StephenS's user avatar
  • 27.8k
35 votes

What prevents someone from hijacking a radio frequency mid-air?

This sounds like a “people problem”. That kind of problems is best solved with enforcement. Source of radio broadcast can be localized and it is not particularly difficult. There are techniques for ...
Jan Hudec's user avatar
  • 56.4k
34 votes
Accepted

Is there any specific reason why Delta Air Lines doesn't have its own callsign?

Delta Air Lines uses the ICAO three-letter designator DAL and the ICAO telephony designator (also known as callsign) DELTA. In general, callsigns should be similar or equal to the name of the airline ...
Bianfable's user avatar
  • 57.6k
34 votes

Is it acceptable to abbreviate “Foxtrot” to “Fox”?

Bad mics, speakers, ears, or radio connections can remove plosives, siblants, and basically all consonants, in which case the phonetic alphabet is heard as follows: A-a, a-o, ar-ee, e-a, e-o, o-o, o, ...
Dewi Morgan's user avatar
33 votes
Accepted

Can I ask ATC a radio check with a handheld radio?

I think there's a technicality here. Both the operator and the radio station each need, independently, an FCC license. The operator license requirement has been waived for pilots for a long time, ...
Max R's user avatar
  • 3,818

Only top scored, non community-wiki answers of a minimum length are eligible