Just how high do mobile signals go?

[LewisRaz]

Its because the earth is flat

All these replies and only one person really understands it

 

[SexyGreyFox]

Can anyone explain how his iPhone managed to get a signal from that height over each country he passed over?

One of the Tin Foil Hat myths about 9/11 was that you couldn't make phone calls while flying so people couldn't talk to their relatives from the plane.
In 1999 I was flying back from Menorca with a Philips D12 and I rang my Mum with no problems.
I was very naughty to do it but believed at the time it was necessary to contact her.