John Kasupski wrote:
The reason aircraft radios are in AM is that back in the early days AM
was the standard, and by the time FM became a standard for two-way
comms, there were just so many aircraft out there with AM radios that
replacing them all would have been a major nightmare, for financial
and other reasons...especially for commercial airline companies that
would have hundreds of radios to replace.

The reason is that two simultaneous AM signals are heard as two signals,
while two simultaneous FM signals are heard as only the stronger signal
(possibly with hash if the weaker signal isn't a lot weaker). It's
of overriding importance to be able to hear a second station on frequency
in case of emergency and busy frequencies.

--
It's unfair to characterize Kerry as a flip-flopper. He's consistently in
favor of marrying a rich widow and buying your way into the White House.
-- Rex Tincher