Does any aviation authority have a recommendation of how long to listen after changing to a new frequency before making a transmission?
I was always taught:
- Change frequency
- Give it a good 3 count
- If no one is talking, transmit
The FAA just advises a pause as per the AIM [4-2-1] but gives no time specifically
a. Listen before you transmit. Many times you can get the information you want through ATIS or by monitoring the frequency. Except for a few situations where some frequency overlap occurs, if you hear someone else talking, the keying of your transmitter will be futile and you will probably jam their receivers causing them to repeat their call. If you have just changed frequencies, pause, listen, and make sure the frequency is clear.
You will also learn to anticipate the flow. For example if you hear a controller issue something you should expect to hear the aircraft read it back. Once you get a feel for the cadence of chatter you will have even less issues.
My EASA compliant RT theory book states listen in for at least 5 seconds.
Whether that's a hard and fast regulation or a rule of thumb isn't stated, but the idea is you listen long enough to ensure nobody else is talking before opening your microphone.