Is the blades departing a result of the feathering shaft screw backing out, or is something breaking? It is standard procedure to loctitie the feathering shaft bolts before flight on all CP helis. Lots argue that BnF and RTF models should not require this, but I still find it a good practice. If it is just the FS bolts coming out, then that is easily prevented. If it is something else going on then I am concerned.