From this point on, the Belfast factory became increasingly important as it was thought to be well beyond the range of German bombers. However, Belfast and the aircraft factory were subjected to bombing by German aircraft during the Easter week of 1941. To meet the increased requirement for its aircraft during the war, satellite factories near Belfast were operated at Aldergrove and Maghaberry, producing 232 Stirlings between them. In 1940, bombing damaged Supermarine's factory at Woolston and the incomplete Type 316 prototypes. In November 1940, development of the 316 was formally cancelled, leaving the Stirling as the only B.12/36 design.