[Col Ford]

The RAF Mustang Mk.1A armed with 4 x Hispano Mk..II* 20mm cannon served in front line service from June 1943 until August 1945. They served with a number of the RAF's tactical reconnaissance squadrons and were well regarded by the pilots who flew them in that role.

There is documentation from 1944 and 1945 indicating that the RAF was still interested in Mustangs, including the Merlin engined variants, to be armed with 4 x 20mm cannon. However the expediencies of quantity of production and not wishing to delay deliveries meant the 0.50in HMG armament preferred by the USAAF was accepted.