OK..........I've been in the hobby since 1979 and I've never, never seen a plastic spinner fail. I've seen an aluminum spinner seperate itself from the plane but I've never seen a plastic spinner come off of a plane or self-destruct. I have 10 flyable planes in my hanger at this time and 6 of them have plastic spinners.........and I don't think I can count the ones I have successfully used.