A few days ago, I was flying into my base airport in the USA with a control tower, and something/someone was jamming the frequency with what the tower thought was a hot mic after I had established communications and received instructions.

They thought it was us with a hot mic (Spoiler: It wasn't), and they managed to somehow broadcast through the hot mic tying up the frequency.

Luckily, that tower operates on two frequencies, so I changed over to the other one and managed to get back in contact with the tower and continued in to the airport; I made sure they knew that we were not the cause of the frequency jam. That was clear, since nothing was jammed when we changed to the other frequency, plus the original frequency continued to remain jammed.

When such a situation as I describe above happens, what are the procedures that ATC controllers have to follow, and how did they manage to transmit through the hot mic like they did?


1 Answer 1


Honestly, there is no guarenteed way we can solve such a problem, and it is extremely frustrating when it happens. A few possible solutions:

The radio transmitter associated with the tower frequency is usually quite powerful, so (at least for nearby aircraft) it may be possible to override the other transmission by simply transmitting normally. AFAIK, the transmitter is actually designed to be more powerful than aircraft transmitters as a safety feature. Sounds like this is what happened in your situation. This is usually only the case for tower frequencies (not ground/approach etc.)

Sometimes there is an obvious alternative frequency you can use, and maybe some of the pilots will try tuning to that frequency. We could also do a call on 121.5 and ask everyone tuned to the tower frequency to check for stuck mic. This wouldn't help for small GA aircraft with only one radio, since they won't be listening to 121.5.

In CPDLC airspace (en-route environment), ATC can send a "CHECK STUCK MIC" message to relevant aircraft.

In the end, the pilot with a stuck mic will usually realise after a while of apparent silence on the frequency.

Here is a recording of a stuck mic causing issues at JFK:

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    $\begingroup$ For some aircraft they handle a stuck mic in the audio panel. My audio panel in my 177 has a "stuck mic detection" that automatically stops transmitting if the mic is on for more than something like 30 seconds. $\endgroup$
    – Ron Beyer
    Commented Sep 22, 2019 at 2:08
  • $\begingroup$ @RonBeyer thanks for sharing that. I had never heard of that before. $\endgroup$ Commented Sep 22, 2019 at 19:44
  • $\begingroup$ @RonBeyer that means if you have a long message to transmit (e.g. description of a medical emergency), you have to split your message into smaller pieces to avoid being cut in the middle of your message, doesn't it? $\endgroup$
    – Manu H
    Commented Dec 7, 2019 at 9:59
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    $\begingroup$ @ManuH 30 seconds is a long time, I doubt such a limit would cause issues except in very extreme cases $\endgroup$ Commented Dec 7, 2019 at 11:30
  • $\begingroup$ @ManuH Yes, of course, however as J. Hougaard says, 30 seconds is a lot of talking, usually a pilot would just "request medical" either on the runway or at the gate in that case. $\endgroup$
    – Ron Beyer
    Commented Dec 7, 2019 at 21:18

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