We all know the stories and may even have witnessed it on the frequency: ATC calls a flight several times without response and a little later you can hear an intercepting aircraft trying to contact the respective flight on 121.5 - from a position adjacent to that aircraft!
This is a situation nobody ever wants to be involved in, especially not as a pilot in command.
The most important barriers to avoid such a situation are proper use of our radio equipment and being serious about radiotelephony (RT)!
Maybe using RT daily is so routine that we tend to forget its importance and stray from the ideal. But it certainly is a backbone of our safe operation of aircraft. Therefore, it is urgent to use it properly and be mindful about the implications of non-standard communication.
- Communicate effectively, that means standard English phraseology unless it is absolutely necessary to use another language or non-standard phraseology.
- Carefully read back instructions and if in doubt, just ask again.
- Use CPDLC where available. It is especially useful for frequency changes.
- 121.5 and other emergency frequencies are for this purpose only! It is not funny to be funny on these ones or to misuse it for chatter. The more distraction takes place on 121.5, the more pilots will be inclined to lower the volume or even deselect the channel.
- ALWAYS monitor 121.5 with a proper volume even if you encounter temporary disturbances. It may be your last line of defence!
- Be aware of FIR boundaries and if the controller does not transmit a new frequency, ask for it.
- Crosscheck frequencies using your charts or electronic route manual.
- In case of prolonged radio silence, perform a radio check.
- Consider use of headsets – at least if only one pilot is in the cockpit.
ICAO EUR OPS Bulletin 2021 001 with principles and best practices in case of loss of air-ground communication:
https://www.icao.int/EURNAT/Pages/news_articles/EUR-OPS-Bulletin-2021-001.aspx
Promotion Material for the Prevention of Loss of Communication on SKYbrary:
https://skybrary.aero/articles/promotion-material-prevention-loss-communication