Lost Radio control during flight

[C willis]

Hello , I have the flywing 450 V2 Airwolf for 6 months now. Yesterday for some reason the airwolf lost control . I could not control it with the transmitter, it was flying away on it's own, Even the return to home, did not work. I was forced to stop the motor, and of course it;s scrap now. What could cause this to happen. Please advise