A Failsafe it USELESS if you have no power going to the servos at all. Yes it is good if you voltage gets low and it helps you but if you have no power there is nothing to close your wide open throttle servo. A throttle return spring is a good investement. I forgot to mention I had my monsoon take off on my and it was my ON/OFF switch. A wire on the switch had broken off and NO POWER, and I ran a spektrum! You also did not say if when your buggy ran away if you still had steering or not. If you did and no throttle then the you know it is the throttle servo.