Fail safe is just A helping tool, not A cure all. Sometimes it works and sometimes it doesn't. Bruce pointed out that you don't know in advance at what attitude your plane is going to be in at any given moment or where it is pointing at time of signal loss. As long as the engine is shut down everything else is A mute point. I only set my throttle to kill the engine, all else will take care of itself. I have seen planes get loose from the pilot and go into the pits and end up in the spectators area, pilot error, fail safe never figured into it. I have seen A giant 120 inch bipe loose signal and do loops forever while being pushed by the wind towards A fuel storage site, fail safe never kicked in. It is only A help thing and nothing to be counted on, if you have it use it, if you don't then don't worry about it.