

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.
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