 Complete the following phrase:  Stapleton left 603 Squadron in April 1941 and served in various units, including flying Hurricats Hurricane fighters converted as catapult-launched convoy escorts with the Merchant Ship Fighter Unit, as a flight commander with 257 Squadron, and as an instructor at Central Gunnery School before taking over Command of No. 247 China-British Squadron, part of 124 Wing, 2nd Tactical Air Force, flying Typhoons from beachhead code B.6, northern France in August 1944. Initially the squadron helped close the 