Just a nit, but aircraft/airport communications use AM not FM. This is deliberate, because FM's "capture effect" would mask other transmissions that inevitably occur when two parties randomly press PTT at the same time. With AM, you'll hear a tone, which is the difference frequency between the two transmitters, so you'll know that somebody missed something, and it will probably be repeated. If it were FM only, it would be less obvious that some communications were missed.

https://en.wikipedia.org/wiki/Capture_effect

I appreciate the correction, anonymousiam! You are absolutely right - it's AM and for exactly the reasons you articulate.