What else do you expect it to do?
A plane without a pilot WILL eventually crash.
God "lets" a lot of things happen. Why not "let" the pilotless plane behave in the normal way a pilotless plane would behave?
Letting something happen and causing something to happen are two different things. Yes, Jesus' robes will be blood-soaked in his second coming, as the bible says. But there is no rapture, and the plane thing isn't the defining thing for me, the Word is, but it should put pause in any rapture-believer that all these planes are going to crash in one day as an act of Jesus to kick off the Tribulation.