The four-engined Me 323C was considered merely a stepping stone to the six-engined D series; it still required the five-engined Heinkel He 111Z "Zwilling" or the highly dangerous, "vic-style" "Troika-Schlepp" formation of three Messerschmitt Bf 110 heavy fighters and underwing-mounted Walter HWK 109-500 "Starthilfe" rocket assisted takeoff units to get airborne when fully loaded, but it could return to base under its own power when empty.