I still don't understand the problem that people may be having here. I've put close to 200 flights on 28% Wild Hare planes and have NEVER had a wing retainer screw loosen in flight. All I've used is a flat fender washer and a lock washer between the bolt head and fuselage. Other than drilling the locator pin and using the hairpin cotters that are included in the hardware pack, there is no need to do any more than that. Really!