[2] In January 1943 the squadron joined the 127 (Canadian) Wing and moved to Redhill Aerodrome airfield.
[3] In preparation for the Normandy landings the 127 Wing was assigned to RAF Second Tactical Air Force.
After the allied breakout and quick advance towards the Reich 421 squadron was based in Evere in Belgium by October 1944.
Having been disbanded shortly after the war the squadron was re-activated on 15 September 1949 at Chatham flying Vampire aircraft.
At the end of the Cold War the squadron was disbanded and its aircraft and personnel returned to Canada.