Sean wrote:

That may be so but transistors made a lot more noise than printed circuit
boards and no one (well maybe some private A/C) is using AM signals to
navigate anymore (ADF)

And did they really prove that or did someone just find a radio in the
wreckage and say "oh this must have caused it" because the public would
really be worried if they said it crashed because an engine fell off?

Sean

"D.D. Pepper" wrote in message
...
Following a midair crash over Manhattan in the late 50's/early 60's that
was traced to a transistor radio in one of the airplanes that was tuned
to a NYC AM station that interfered with that plane's avionics,
non-approved radios were banned from use in in-flight commercial
airliners. I don't blame the airlines for being a bit "paranoid".


ISTR that it was tuned to an FM station and the oscillator was on the
VOR frequency.

Lots of AM NDBs still in use and being installed, pretty hard to find an
Instrument Landing System in North America which does not include at
least one AM NDB (acually many, if not all, are now AME - Carrier and
one sideband).