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A column in Radio World outlines the amazing in and out reception of FM signals as a speeding jet passes over various cities from thousands of miles up.
I actually did this a very, very long time ago coming back on a flight from New York City, of all places. The stations were coming in so fast and fading out so quickly, that if you didn't catch an ID in the short window the signals came through, it was gone and replaced by another on a nearby frequency.
It was an amazing experience and something I've only ever done once. There was no RDS in those days, so the guy in the linked article really had an advantage. But if you ever get the chance, it's simply amazing.
The FM Band From 30,000 Feet in the Air
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I did this once while on a plane from Toronto to Acapulco in 1986.
As you mentioned, the stations came and went very quickly. It was interesting to hear the announcer's voices and they transitioned from what I would consider accent-free to very thick southern ones, and then to Spanish as we passed over Texas and into Mexico.
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I once made an "aeronautical mobile" ham radio contact on 20 metres with a flight crew member in a commercial airliner. From his accent I speculated that he was German, but wouldn't answer when I asked if he was with Lufthansa.