Not for electric-powered models, because most electronic speed controllers will cut the motor if a valid signal is lost. I/C models are a totally different matter; every different radio manufacturer seems to have a different way of setting up the position of the servos in failsafe mode. It used to be possible to buy 'stand-alone' failsafe units but I'm not sure if or where there are any still available other than those designed specifically for petrol engines.
DaveM
