The A-36A was a dive bomber developed from the Mustang I. Work on converting the new North American fighter for the attack role had begun in 1941, at a time when funding was not available for new fighter aircraft (the first Mustangs to enter American service were actually a small number of P-51s, taken from a British order after Pearl Harbor).
The A-36 featured a strengthened wing, designed to carry one 500 lb bomb under each wing. Armament was chanced to six .50 inch machine guns, two under the nose and two in each wing. Dive brakes were added to the wings, to reduce the speed in the dive from the 500 mph of a standard P-51 to 390 mph. This was done to increase the accuracy of the A-36. The A-36 was powered by the Allison V-1710-87 engine, which provided more power at low altitude – peaking at 1,325hp at 3,000 feet.
The USAAF placed an order for 500 A-36s on 16 April 1942. The type was used by three units, starting with the 27th Fighter Bomber Group. That unit flew the first A-36 mission on 6 June 1943, from their base in Rasel Ma, in French Morocco. The A-36 was also used by the 86th FBG, also in the Mediterranean, and the 311th FBG in northern Burma.
Like all variants of this aircraft, the A-36 was often known as the Mustang. It was also unofficially known as the Apache, the name North American had originally tried to give to the Mustang. The aircraft was also sometimes known as the Invader when used in Sicily and Italy.
The A-36 was a successful aircraft. The type flew over 23,000 combat missions, dropping 8,000 tons of bombs, and claiming 84 enemy aircraft in aerial combat. Only 177 A-36s were lost to enemy action, a loss ration of under 1%, very impressive for a ground attack aircraft. This is particularly impressive when one remembers that the P-51 later earned a reputation for being vulnerable to ground fire in Korea.