It's not really an air-gapped system if it accepts unauthenticated external radio signals and changes state in response, which is what would be happening in tha

It's not really an air-gapped system if it accepts unauthenticated external radio signals and changes state in response, which is what would be happening in that case. You don't need much imagination to think of various attacks that a spoofed GPS signal could open up, if you were able to cause a system to have an incorrect time.