Aircraft fly higher, which means they pick up ground radio signals from much further away - both good (ATC communication, ground-based navigation beacons) and b

Aircraft fly higher, which means they pick up ground radio signals from much further away - both good (ATC communication, ground-based navigation beacons) and bad (intentional jamming). On the ground, the radio horizon is about 20-40 miles. In the air, the radio horizon is about 200-400 miles.