This has happened twice now. Have flown successful GS missions before and after the first incident. Had to replace a motor , it flew fine after but motor did not sound as smooth as other 3 when free spun so decided to replace it. Have not tried since the last incident. Just a bit gun shy at this point. Have searched the forum and have not been able to find mention of this Could not shut down the bird either time. Had to physically turn off via battery. Any one else experience this? Am I missing something? Btw the bird was on the ground at the start of both missions. Should I initiate mission after launch?