First off, only for a very short time in mid- to late-1940, was the name ‘Apache’ applied to the Mustang – the A-36 specifically. In fact, at the time, the A-36 was not even on the drawing boards. The name was used, however, in several magazine advertisements in the late 1940s including Popular Science that showed the NA-73 or Mustang Mark I as it was named by the British Purchasing Commission. Moreover, except for an attempt by MTO A-36A pilot, Lt. Robert B. Walsh, around mid-1943 to name the A-36 the ‘Invader’ to distinguish it from P-51s, P-51As, F-6As and F-6Bs, was the name ‘Invader’ was not even considered. Officially, but temporarily, the name ‘Invader’ was seen in an official government document. In the Aircraft Recognition Guide issued by the US War Department on 15 October 1943, under the NAA P-51 Mustang heading, it reads: ‘Dive Bomber version [of the P-51] known as A-36 Invader.’ Nevertheless, the name ‘Invader’ was never officially adopted for the A-36A. Finally, the name ‘Invader’ was officially assigned by the Douglas A-26 series of attack aircraft. Thus, as it stands, the A-36 was never named ‘Apache’ or ‘Invader’ and it remains a Mustang – period.
On 5 June 1944, a flight of four A-36As led by USAAF First Lieutenant Ross C. Watson flew through a heavy overcast on the approach to their target: a large, well-defended rail depot and ammunition storage facility at Orte, Italy. During this well-planned attack, this quartet of A-36As scored several hits while under intense anti-aircraft artillery fire. Watson’s A-36A was hit and damaged by ground fire. However, under heavy ground fire, Lt. Watson continued his attack and was able to destroy the ammo dump before he made an emergency landing at an advanced Allied airfield. This mission alone dispelled any doubt of the true effectiveness of the A-36A as a dedicated light attack dive bomber.
The North American A-36A Mustang was nearly identical to the RAF Mustang Mark I, but was equipped with four wing-mounted Browning M2 .50 calibre machine guns, two nose-mounted .50 calibre machine guns, wing-mounted dive brakes and two under-wing bomb racks to carry 500 lb bombs for its intended use as a low-altitude dive bomber. They had the same fuel, water and fluids capacities, radio equipment, measurements and so on, but were powered by the single-stage supercharged 1,325 hp water-cooled Allison V-1710-87 (F21R) engine. The Mustang Mark I used the 1,150 hp V-1710-39 engine.
There was a growing need for suitable light attack aircraft in the early months of 1942. NAA immediately offered a modified version of its P-51 Mustang – its proposed NA-97 – to address at least part of this urgent requirement. With USAAF approval to proceed with its NA-97 proposal, NAA initiated work on 16 April 1942. The design, most similar to the NA-73 Mustang I, was given the designation A-36A and it was to be a low-level dive bomber with speed brakes. On 7 August 1942, the War Department approved USAAF contract AC-27396 for the manufacture of 500 North American A-36A-1-NA Mustang airplanes at NAA’s Inglewood, California, facility. The premier A-36A (42-83663) was completed and rolled out in September 1942. Piloted by Bob Chilton, this new version of the Mustang made a successful first flight on 27 September from Mines Field next to the Inglewood factory where it and all subsequent A-36s were manufactured.
After contractor flight testing had been completed, two NA-73 (Mustang Mark I) airplanes were delivered to the USAAF as XP-51 prototypes for evaluation at Wright Army Airfield in Dayton, Ohio. They came with USAAF markings and the serial numbers 41-038 and 41-039. The first XP-51, which was first flown on 20 May 1941 by Bob Chilton, arrived at Wright AAF some three months later on 24 August 1941. Since this airplane was not a ‘sibling’ of the USAAF, it languished on a ramp for several weeks before it was finally evaluated by several USAAF test pilots including Major Benjamin S. ‘Ben’ Kelsey who became one of its staunchest supporters. Kelsey, chief of the Pursuit Branch in the Production Engineering Section of Wright AAF, had high praise for the XP-51 and became instrumental in the A-36A production programme along with his boss Brigadier General Oliver P. Echols. It was these two officers that were wholly responsible for getting the contract to NAA for the production of 500 A-36A airplanes for the USAAF.
After the USAAF had finished its evaluation of the first XP-51 at Wright AAF to which it had first arrived on 16 December 1941, it was flown to Langley Army Airfield in Hampton, Virginia, for National Advisory Committee for Aeronautics (NACA) flight test evaluations of its laminar flow wing in particular, its performance and aerodynamics in general. It arrived there on 1 March 1942 and the first test flight was made that same day. The last test flight was flown on 15 May 1943 totalling twenty-two flights and about twenty-four hours’ flying time. Thirteen months later, NACA published a Wartime Report entitled Flying Qualities and Stalling Characteristics of North American XP-51 Airplane (A.A.F. No. 41-38) in April 1943, two months and several flights before flight testing had finished.
The 27th Fighter-Bomber Group of the 12th Air Force was operating in the European-African-Middle Eastern (EAME) Theatre of Operations and was based in North Africa at Ras el Ma Airfield, French Morocco, when it first received its A-36As in April 1943. It subsequently moved to Korba, Tunisia, and from there it flew its first combat mission on 6 June 1943.
The 86th Fighter-Bomber Group (Dive) was the second unit to receive combat-ready A-36As in North Africa during May 1943, but it was the first outfit to get pilots that had been specifically trained and qualified to fly combat missions on the A-36A in the EAME Theatre. The A-36As were at first based at Oran Es Sénia Airport in Oran, Algeria, but moved to Marnia Airfield in French Morocco when it first flew its initial combat mission on 6 June 1943.
The 311th Fighter Group (Dive) and its 382nd Bombardment Squadron (Dive) of the 10th Air Force arrived from the US via Australia with its A-36As at Nawadih Airfield in India beginning in July and became operational on 14 September 1943. It flew its first combat mission on 16 October against enemy aircraft near Sumprabum, Burma, and three of its A-36As failed to return. This unit transferred from Nawadih Airfield to Dinjan Airfield, India, on 19 October 1943 for continued operations in the CBI. The 383rd 384th and 385th Bombardment Squadrons (Dive) likewise became part of the 311BG (Dive).
For the most part, the 311BG (Dive) performed ground attack missions over northern Burma and fighter escort missions throughout the theatre. It also helped protect transport aircraft flying ‘The Hump’ air route to China. In July and August 1944, after moving once more to Tingkawk Sakan Airfield in Burma, it helped to support numerous troop movements including the famed Merrill’s Marauders. Its final move was to the 14th Air Force in China where it remained until the end of the war. It was based at Pungchacheng Airfield from 28 August 1944 to 14 December 1945. At the end of the war, it helped ferry P-51s to China to equip the Chinese Air Force before it returned to the US in December 1945.
The 311BG (Dive) was the third and last group to receive the A-36A light attack dive bombers during the Second World War.
One A-36A-1-NA (42-83685), the 26th one built, was turned over to the RAF in March 1943 to be evaluated by the A&AEE at Boscombe Down. It was designated Mustang Mark I (Dive Bomber) and issued RAF serial number EW998. This evaluation process found that it was no better than the Hawker Typhoon series of fighter-bombers that served the RAF and no orders were forthcoming.
Length: 32 ft 3 in.
Height: 12 ft 2 in.
Wing span: 37 ft ¼ in.
Wing area: 233 sq ft
Empty weight: 6,087 lb
Gross weight: 10,700 lb
Propulsive system: one 1,325-hp Allison V-1710-87 (F21R) Vee
Propeller: three-bladed constant speed electrically pitch actuated 10-ft-6-in.-diameter Curtiss Electric Propeller
Maximum speed: 366 mph at 5,775 ft (level flight)
Armament: six Browning M2 .50 calibre machine guns – two nose-mounted, four wing-mounted; two 300 or 500 lb bombs
A-36A Combat Units in the Second World War
27th Bomb Group (Light); 16th Bomb Squadron (Light); 17BS (L); 91BS (L); 86BG (L); 309BS (L); 310BS (L); 312BS (L); 86th Fighter Group; 312th Fighter Squadron; 523FS; 525FS; 526FS; 527FS;
86th Fighter-Bomber Group; 522nd Fighter-Bomber Squadron; 523FBS; 527FBS; 111th Tactical Reconnaissance Squadron; 311FBG; 528FBS; 529FBS