PurposeUSED TO CHECK (GO/NO GO) THE GAP BETWEEN THE SPOILER TRAILING EDGE LOWER SURFACE AND THE UPPER SURFACE OF THE INBOARD OR OUTBOARD FLAP. THE GAP CAN BE CHECKED FROM A POSITION STANDING BEHIND THE FLAPAirplane777-200, 777-200ER, 777-200LR, 777-300, 777-300ER, 777FUsage CodeMAINTENANCE 