"Geoff Glave" wrote in message
news:HxHud.9448$eb3.8331@clgrps13...
Any explanation for this?

FM radio generally operates at longer range than AM radio, however it's
limited to line-of-sight. However, when you're 40,000 feet up you can "see"
a lot of transmitters hence the FM signals.

Cheers,
Geoff Glave
Vancouver, Canada



I reckon you just answered the wrong question !!

The reason A.M. radio can not be received in a plane is that it is a Faraday
cage to the (lower frequency) A.M
frequencies, whereas the VHF frequencies can just about get through the
windows.

There may be a bit of frequency / range issue as well but top band and 80 mtrs
gets across the pond so
I don't think this is the issue here...

Nick