For airliners, it's critical for the aircraft to know when it's on the ground because it kicks on autobrakes, and unlocks the thrust reversers for landing.
I'm very curious what the reasons would be for a military aircraft
I'm very curious what the reasons would be for a military aircraft
Someone else was talking about a WoW (weight on wheels) sensor that locks the landing gear down with no manual override but again doesn't sound like a catastrophic thing to accidentally trigger in air (indeed this particular aircraft had a landing gear that was stuck so a faulty WoW sensor wouldn't have made the problem worse).
This particular mode switch thing sounds like it does something to the flight control that immediately causes catastrophe if turns out you're still in the air.