<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by NickW:
You can hinder most handhold GPS receivers just by putting your hand over the antenna, in my experience. I would be extremely surprised if you could acquire enough satellites to get a position fix indoors.</font>
Mine works just fine indoors in a one story house with a tar-and gravel roof.
On an aircraft it has to be near the window since the signal cannot penetrate the metal skin.
It was kind of fun for a few flights, but then the novelty wore off. If BA really allows GPS on Concorde, -that- might be worth trying!