The limits are higher altitude and faster speed then you've ever been. If the Concorde was around you would see it firsthand. Weapons would be worthless against first world defences at airliner height and speed. Gps receivers shut down on weather balloons regularly, it's a known issue
The limits are real, encoded in public law. I don't understand how you could possibly disagree with me on this point
The reason your GPS receiver does not work on a plane is likely because it's processing algorithms aren't tuned for those speeds. The popular Ublox NEO-6M for example needs to be explicitly switched to "airborne" mode.
The fact that you are enclosed in a faraday cage also isn't helping, but they make planes from plastic now, so this shouldn't always be the case.
Unfortunately many cheap GPS chips use the (incorrect) or definition, not and. It was a pain to find one that works above 59000ft but very slow speed for a weather balloon project some years ago.
I like using a NSF funded mobile app "Flyover Country" [1] to identify features in the landscape when I fly. You can download the maps and data for you flight path a head of time and then use it in airplane mode on the plane. GPS works fine (by the window) and the app locates your position on the map.
