Ah ok confusion and yes exactly that with the tumble and chaos results ;-)Ah sorry I was referring to stopping the motors in connection with " The blood you see on the blade was from my hand as the seemingly dead drone sprung to life when I picked it up ;-) lesson one always switch off..... "
The tumble is, I think, what you would expect if one prop, for whatever reason, stops to produce lift, that non lifting 'corner' drops and chaos ensues.