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 e

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.