I have not had that problem yet, but I have found the weak link - it's the tail motor. I popped the endbell off the first one somehow(good luck trying to put it back on), and the second one seems to have bound up or something. Now it will only be flyable for about 30 seconds and then the tail rotor doesn't have enough power to keep the heli from torquerolling. Of course, next to the 5-in-1 unit, it is the most expensive part, too
