hi always have the screws that are holding your servos in there traybe completely into the wood below the servo-if the servo tray is only 1/8 plywood-put a piece of hardwood below it were the scews are anchoredyou must have your screws secured into wood fully-and then i still have seen the screws -unscrew due to fuse vibration-i have seen a plane land with four servo screws-out of four almost totally unscrewed-and the fellow was a very accomplished builder for many yearsdo check your servo screws and all other screws - every 10-15 flights as normal maintanencecan save your plane to fly another daydo landing gear more often