Mxsmanic wrote:

Perhaps this is a naive question, but: Why don't voice radio
communications for aviation use FM radio instead of AM radio?

I understand it is because of a characteristic of FM called "capture
effect" that blanks out weaker transmissions when two radios transmit at
the same time. The listener would have no idea that a second, weaker
transmission was being made.

With AM, when two radios transmit on close frequencies, you either hear
both signals poorly, or you get squeal, which is the sum of the two
signals. This characteristic is considered important when you have elevated
transmitters that can be hundreds of miles away, like on aircraft.