PART 2

DEVELOPMENTAL HIGHLIGHTS, 1940 TO 1945

‘I should like to see this nation geared up to the ability to turn out at least 50,000 planes a year. I believe that this nation should plan at this time a program that would provide us with 50,000 military and naval planes. I ask for an immediate appropriation of $896,000,000. And may I say that I hope there will be speed in giving the appropriation.’

President of the US, Franklin D. Roosevelt, 16 May 1940

In early 1940, the US Army Air Corps had around 1,400 bombers and fighters of which most (some 900) were for the most part obsolete. And many of the aircraft types that played the most significant roles in the Allied successes had not even been built yet – including the Mustang. By the end of the war, however, the US had produced some 250,000 military airplanes which had met the goal of Roosevelt. (Roosevelt died 12 April 1945, but lived long enough to see the production of an entire armada of aircraft totalling well over 200,000 airplanes at the time of his untimely passing.)

The history of the North American Mustang series of aircraft traces back to the early spring of 1940 or some twenty months before America was drawn into the Second World War. Great Britain had a desperate need for combat aircraft at this time, especially fighters, as it had been at war with Germany for some six months. Great Britain’s Hawker Hurricanes and Supermarine Spitfires were rolling off their respective production lines but in limited quantities. To bolster its growing requirements for fighter aircraft, Great Britain was procuring US-built fighters such as the Curtiss Kittyhawk Mark I of which it wanted more than Curtiss could provide at the time.

In the US, several airframe contractors were producing early models of their pursuit-type aircraft such as the aforementioned Curtiss Kittyhawk I (P-40D), the Lockheed P-38 Lightning, the Bell P-39 Airacobra and the Republic P-47 Thunderbolt. The RAF despised the twin-engine Lightning and it never wore permanent RAF colours. The RAF received three P-322 airplanes from Lockheed which were designated Lightning Mark I, but soon returned them. It did procure a number of ‘Razorback’ and bubble-top P-47D Thunderbolts, however, but these were not put into RAF service until 1944. Respectively, these were referred to as the Thunderbolt Mark I and Thunderbolt Mark II. The RAF also acquired Airacobra Mark IA (P-400 and/or P-39D) airplanes in early 1941. So, it was only the Kittyhawk Mark I that was preferred and available to the RAF in the spring of 1940.

The belligerents during the Second World War fought as partners in one of two major alliances: the Axis Powers and the Allied Forces. The three principal partners in the Axis alliance were Germany, Italy and Japan. These three countries recognised German control over most of continental Europe; Italian power over the Mediterranean Sea; and Japanese dominance over East Asia and the Pacific. Although the Axis partners never developed institutions to coordinate foreign or military policy as the Allies did, the Axis partners had two common interests: 1) territorial expansion and foundation of empires based on military conquest and the overthrow of the post-First World War international order; and 2) the destruction or neutralisation of Soviet Communism. On 1 November 1936, Germany and Italy, reflecting their common interest in destabilising the European order, announced a Rome-Berlin Axis a week after signing a treaty of friendship. Nearly a month later, on 25 November 1936, Nazi Germany and Imperial Japan signed the so-called Anti-Comintern Pact directed at the Soviet Union. Italy joined the Anti-Comintern Pact on 6 November 1937. On 22 May 1939, Germany and Italy signed the so-called Pact of Steel, formalising the Axis alliance with military provisions. Finally, on 27 September 1940, Germany, Italy and Japan signed the Tripartite Pact, which became known as the Axis alliance.

Even before the Tripartite Pact, two of the three Axis powers had initiated conflicts that would become theatres of war in the Second World War. On 7 July 1937, Japan invaded China to initiate the war in the Pacific, while the German invasion of Poland on 1 September 1939 unleashed the European war. Germany remained heartless, and in April 1940, took Norway. In May, both Holland and Belgium fell. And in June, Nazi Germany chased Great Britain off the European continent at Dunkirk and defeated France. Italy entered the Second World War on 10 June 1940 as the defeat of France became apparent. As a result, most of the aircraft on order to France were subsequently diverted to Great Britain.

NAA chief engineering test pilot Bob Chilton posing by one of the two XP-51B prototypes. (NAA via USAF)

Great Britain needed hoards of combat aircraft to help fend off attacking Luftwaffe airplanes from across the English Channel. It had to bolster its increasing numbers of Supermarine Spitfires and Hawker Hurricanes. To do this, in part, it ordered P-38 Lightnings, P-39 Airacobras and P-40 Warhawks from American aircraft manufacturers, Lockheed, Bell and Curtiss respectively. In fact, since it was favoured over the P-38 and P-39, the RAF was in a desperate need of more P-40Ds than Curtiss could supply in haste. So in part, this is why the British Purchasing Commission had asked NAA to help produce P-40D airplanes. As it turned out, however, this request became the template from which the Mustang form was originally initiated.

1940

There was not much to celebrate on New Year’s Day 1940 in Europe, Asia, throughout the Western Pacific and the Middle East. While Japanese military forces were attacking and occupying countries in Asia and the Western/Central Pacific, Germany had invaded Southern and Western European countries.

On 11 January 1940, NAA began its NA-67 programme as the follow-on to its earlier NA-63 XB-28 programme. This was a result of USAAC contract number AC 14012 to build one XB-28A airplane: USAAC serial number 40-3058. These experimental medium-class bombardment aircraft were optimised for high-altitude performance in that they were fully pressurised. The NA-67 was similar to the NA-63 but was scrutinised as a possible high-altitude photographic reconnaissance platform instead of pure bombardment duties. XB-28A was lost on 4 August 1943 when it crashed into the Pacific Ocean off the coast of Balboa, California. The five-man crew baled out and survived (pilot was Robert C. ‘Bob’ Chilton).

The XB-28 was first flown on 26 April 1942, the XB-28A later that year.

In January 1940, the government of Great Britain established the British Purchasing Commission to purchase US combat aircraft to supplement its domestic airplane production. While the main body of the BPC remained in Great Britain, an important arm was soon headquartered in New York City, New York. Sir Henry Self was appointed Director General of the BPC arm in New York City. In a meeting with NAA president Dutch Kindelberger on 28 February, Sir Henry Self asked if he would consider manufacturing Kittyhawk Mark I (P-40D) airplanes at his facility under licence from Curtiss-Wright.

British Purchasing Commission

Prior to the outbreak of the Second World War, both the British and French Governments investigated the possibilities of purchasing armaments from the US and Canada. The French Air Mission led by M. Jean Monnet in 1938-1939 had placed important contracts in the USA for complete aircraft and aero engines. The British Air Ministry also sent a Mission to the USA and Canada in 1938, headed by Sir Henry Self. Apart from making special purchases of aircraft in the US, the Mission also explored the possibilities of increasing the potential of Canadian aircraft production and the manufacture of British types under licence.

Discussions about the opening of a purchasing agency in North America had been going on since the beginning of 1939 and in August of that year, Lord Riverdale visited Washington and Ottawa. On his return, he recommended the setting up of a Purchasing Commission in Washington. In the early days of the Ministry of Supply, a British Supply Board was set up in Canada to purchase munitions from Canadian sources. In November 1939, an offshoot of this became the British Purchasing Commission or BPC in Washington D.C., responsible for purchases from the USA. In the same month, the ‘British Supply Board in Canada and the US’ was established in Ottawa, Ontario, Canada, with Lieutenant Colonel J. H. M. Greenly as Controller General and Chairman. The British Supply Board was not a direct purchasing agency and its functions were to coordinate purchasing in Canada and the US. Orders for Canadian material were to be placed by the British Supply Board through the Canadian Government’s own Supply Board, whilst American orders were to be dealt with by the newly formed British Purchasing Commission, headed by Mr. Arthur B. Purvis in New York. The formation of the new organisation was announced on 7 November 1939, just three days after the repeal of the US arms embargo under the revised Neutrality Act.

In January 1940, the Anglo-French Purchasing Board was set up in New York with Arthur Blaikie Purvis and Bloch-Laine as Chairman and Vice-Chairman respectively. When it became apparent that the fall of France was imminent, the Purvis/Bloch-Laine association, backed by the authority of the Anglo-French London Committee, assigned existing French contracts over to the British Government. After the collapse of France, the British Supply Board in Canada was founded and United Kingdom orders were placed direct with the Canadian Department of Munitions and Supply in Ottawa, Canada.

Increased demand for the production of aircraft and aero-engines in the US led to the formation of the British Air Commission under the Director Generalship of Sir Henry Self. Functioning first of all within the framework of the British Purchasing Commission, it became established as a separate Mission in November 1940, responsible to its parent body, the Ministry of Aircraft Production. About this time, other organisations were emerging from within the British Purchasing Commission to become established Missions in their own right, each representing their parent UK Ministry. The Director-General to succeed Sir Henry Self was Clive Latham Baillieu.

On the formation of the Ministry of Aircraft Production in 1940, the minister sent a personal representative to North America to make arrangements for the supply of American and Canadian aircraft and equipment. In August 1940, a special Technical Mission, headed by Professor Tizard, went to America to exchange scientific information, especially that relating to aviation. In October 1940, the Ministry of Aircraft Production set up a British Air Commission in Washington on a formal basis to be the link between the ministry and NAA departments and suppliers. In July 1942, the British Purchasing Commission became the British Ministry of Supply Mission. Meanwhile, the British Supply Board had been dissolved in 1940, being replaced by a number of smaller technical missions. A British Ministry of Supply Mission to Canada was set up in December 1942.

In January 1941, the British Supply Council in North America came into being. The Council consisted of the heads of the various Missions who met at regular intervals to coordinate policy and discuss common subjects. A Civil Secretariat was also installed to work in conjunction with the Council. The Chairman communicated directly with the North American Supply Committee to the Home Cabinet. In December 1942, the Prime Minister appointed Col. J. J. Llewellin (the former Minister of Aircraft Production) as Resident Minister for Supply in Washington. He was succeeded in 1943 by Sir Ben Smith, who remained in the post until the war ended.

After the US declared war, it became apparent that the procurement organisation of both the US and Great Britain would need to be closely integrated, and to meet this requirement, the first of the Combined Boards came into being early in 1942. In July 1942, the British Purchasing Commission was renamed as the British Ministry of Supply Mission, and later in the year, the British Army Staff was linked with this organisation. The British Air Commission was the concern of a senior official of the ministry, known at first as the Director of Canadian and American Purchases; in 1941, as the Controller of NAA supplies; in 1942, as the Controller of North American Supplies and Repairs; and from 1943, the Controller of Repairs, Equipment and Overseas Supplies. In 1945, the Commission changed its name to the British Supply and Air Commission and in 1946, was wound up along with the British Ministry of Supply Mission.

By the summer of 1943, the North American Supply Missions and associated departments had grown into a large complete organisation resembling an ‘overseas Whitehall’. Kindelberger was a respected businessman and had little difficulty in persuading Sir Henry Self to buy an initial batch of 320 pursuit airplanes for the RAF at an average cost of about $40,000US each. Dutch accomplished this some five months before the NA-73X had even flown. Moreover, one month before it had even flown, the BPC increased its order to 620 airplanes.

Kindelberger asked Edgar O. ‘Ed’ Schmued to work up preliminary design drawings and estimated weight and performance figures for the design of a new pursuit airplane powered by the F3R version of the Allison V-1710 engine on 15 March 1940. Schmued was given two weeks to produce his presentation to the BPC. The airplane, according to Kindelberger as told to Schmued, is to be the ‘...fastest airplane we can build around a man that is five feet, ten inches tall and weighs 140 pounds. It should have two 20-millimetre cannon in either wing and it should meet all of the design requirements of the US Army Air Corps.’

One of the first things Schmued set out to do was design a cockpit to accommodate a man that stood five feet, ten inches tall and weighed 140 lb. Arthur C. ‘Art’ Chester, who would become project manager of Mustang engine installations, fitted the bill so therefore the NA-73X cockpit was designed around him. Chester, a famed airplane racer prior to and after the war, used his racing experience to design the propeller spinner, engine nacelle and cowling covers fitted to the NA-73X and NA-73 airplanes. (Chester, president of the Professional Race Pilots Association or PRPA at the time, was killed in a crash during the first San Diego Gold Cup air race in San Diego, California, during 23-24 April 1949 when his racer, ‘Sweet Pea II’, entered into a high-speed stall.)

The US War Department completed its ‘Release of Aircraft Policy’ on 25 March 1940 that gave authorisation to US allies to negotiate contracts for the procurement of the latest US aircraft designs.

Upon Kindelberger’s return to Inglewood, he held meetings beginning on 5 April 1940 with vice president Lee Atwood, chief engineer Ray Rice and chief of aircraft design Edgar Schmued. The main players at NAA involved in the NA-73X programme included Kindelberger, Atwood, Schmued, Rice, chief aerodynamicist Ed Horkey and key aeronautical engineers Art Chester, John Young, Marc W. Malsby, J. Stan Smithson and Larry Waite. Since NA-73 was the next available NAA Charge Number, the programme was first known as X73 and then NA-73X. After some 78,000 engineering man hours, first metal was cut and construction of the NA-73X prototype began for the follow-on NA-73 programme. As the airplane began to take shape, some of its design pieces were not yet available, so NAA was forced to use some off-the-shelf aircraft parts from its other aircraft such as the main landing gear wheels from its own AT-6A Texan supply chain.

With a Letter of Intent received in Inglewood, California, on 10 April for the production of 320 NA-73 airplanes, NAA officially initiated its programme start on a separate one-of-a-kind NA-73X prototype fighter airplane for demonstration to Great Britain and its RAF on 24 April 1940. More often than not in most cases during this time in aviation history, a potential military customer would order two to three prototype aircraft for several simultaneous exhibition purposes including structural integrity, performance and combat capability. Not so in this case as just one NA-73X was ordered and subsequently built. NAA management had promised to produce the airplane as soon as possible, and incredibly on the 102nd day, the airplane was rolled out of the factory on 9 September 1940. Unfortunately, due to a wartime production shortage of the then new 1,150 hp Allison V-1710-39 (F3R) engine, the preferred and design engine for installation into the NA-73X was not available. Powerless, NA-73X was forced to remain on the ground for what seemed to be an eternity for those 

involved.

NAA vice president Lee Atwood had sent a letter to the BPC in New York City on 1 May 1940 promising initial deliveries of the 320 NA-73 airplanes to begin in January 1941 with up to fifty airplanes being delivered every month by 1 October. NAA signed a ‘Foreign Release Agreement’ three days later with the USAAC that authorised it to write formal contracts with the BPC from then on.

During 23-29 May 1940, in meetings between Lee Atwood and British representatives, the BPC signed formal British Air Ministry contract number A-250 for the intended manufacture of 320 NA-73 airplanes in Inglewood. NAA received official approval from the British Purchasing Commission on 20 July to proceed with full-scale production of the 320 NA-73 airplanes previously ordered. Four days later, the US War Department issued ‘Authority to Purchase number 165265’ for the BPC to procure 320 NA-73 airplanes plus two more to be provided to the USAAC at no cost. The two USAAC NA-73 airplanes were designated XP-51. Finally, on 20 September, US Assistant Secretary of War, Robert P. Patterson of the US War Department, officially approved the BPC/NAA/USAAC contract for the manufacture of 322 NA-73 airplanes: 320 for Great Britain and two freebies for the USAAC.

Earlier on 9 September, NA-73X was completed less engine and its design main landing gear wheels. It was temporarily fitted with wheels from the AT-6A Texan supply chain. When NAA finally received the engine for NA-73X in early October, it was not the one the airplane had been designed around. Instead, it was a civilian 1,075 hp Allison V-1710-F3R for which modifications had to be engineered and new motor mounts be designed and installed. The airplane was completed on day 117 and was declared to be ready for flight testing.

Vance Breese, a freelance engineering test pilot for NAA, had prepared the unique NA-73X for its first flight through a series of low-, medium- and high-speed taxi tests to its estimated take-off speed of ninety mph at Mines Field on 15 October 1940. And on the morning of 26 October, after a few engine run-up tests, Breese took off for the first flight of NA-73X. He completed two short test hops of five minutes and ten minutes on that day. Breese completed six more functional checkout flights by 13 November totalling three hours, twenty minutes’ flying time. He happily reported that he flew the NA-73X to a level attitude flight speed of 382 mph that was just as fast as a lighter weight Spitfire carrying half as much fuel.

The first of six NA-68 airplanes had made a successful first flight out of Mines Field earlier on 1 September 1940 with Louis S. ‘Lou’ Wait at the controls.

On 20 November 1940 with NAA test pilot Paul B. Balfour at the controls, NA-73X made a wheels-down dead stick landing in a freshly ploughed field and it flipped over onto its back. As it happened, during this fifth flight test and Balfour’s first on the NA-73X, the engine simply quit running. Luckily enough the airplane did not catch on fire as Balfour was trapped in the cockpit and had to be freed after a rescue crew and investigators arrived on scene. Two reasons for the crash have been given. These are: 1) the engine quit because Balfour had forgotten to switch fuel tanks which starved the engine of fuel; and 2) the engine quit because it was starved of air during the high angle of attack manoeuvres being flown. The latter was due to the short carburettor air scoop employed by the NA-73X. Both reasons are plausible as an engine needs both air and fuel to run. It seems unlikely that Balfour would have forgotten to switch fuel tanks since he was a very experienced pilot. Air starvation was the likely culprit and the carburettor air scoop was extended to the forward edge of the nose on subsequent aircraft. The NA-73X was returned to the experimental shop at NAA for rebuild which included the modified carburettor air scoop. With regards to Balfour, guilty or not, he wound up in Kansas City flight testing B-25 Mitchells. He made the first flight of B-25D-1-NC on 3 January 1942.

As 1940 came to a close, the official name ‘Mustang’ was applied to the 620 NA-73 and NA-83 production airplanes by the British Air Ministry on 9 December and would be delivered to the RAF as the Mustang Mark I. This equine name seemed to appropriately fit this new breed of fighter airplane and the two NA-73 airplanes delivered to the USAAC as the XP-51 prototypes were likewise officially named Mustang.

1941

In the US – at NAA in particular – 1941 began with a whimper and ended with a bang. It was also a year that had seen ever-increasing orders for and production of several types of military combat and training aircraft for both the US Armed Forces and friendly foreign air forces. It was also the year that witnessed the birth of the P-51 Mustang for use by the US Army Air Corps. Vance Breese flight tested the newly repaired NA-73X for the first time on 13 January 1941 out of Mines Field. This was its first flight since it was crash-landed by Paul Balfour nearly two months earlier on 20 November 1940.

NAA manufactured 322 NA-73 airplanes in Inglewood and two of these, the 4th and 10th ones produced, were completed as NA-73 XP-51 airplanes (41-038 and 41-039). Both were ferried to Wright Field in Dayton, Ohio, for USAAC Materiel Command scrutiny, after which both were turned over to the NACA at Langley, Virginia, for additional evaluations. This is 41-038, the first that arrived in December 1941. (NASA)

The second NA-73 XP-51 (41-039) that arrived at NACA-Langley in March 1943. (NASA)

In February 1941, NAA appointed company pilot Louis S. ‘Lou’ Wait to be chief test pilot on the Mustang programme replacing freelance pilot Vance Breese. US Army Air Corps’ Captain M. J. Lee on temporary duty from Wright Field completed seven test flights on NA-73X flying from Mines Field on 16 March 1941. He therefore became the first military pilot to fly a Mustang. Unfortunately, there is no documentation to be found that recorded his experience that day.

Newly hired NAA chief engineering test pilot Robert C. ‘Bob’ Chilton took NA-73X up on 3 April 1941 for a one-hour functional check flight from Mines Field. It was his first flight on the NA-73X. At the time of the accident, NA-73X had only three hours, twenty minutes’ flying time recorded in her log book. She was subsequently flown a number of other times by other NAA test pilots and about twelve more times by Chilton. He also flew its forty-fifth and last flight on 15 July 1941; its log book showing forty total hours. According to Bob Chilton: ‘The NA-73X was a clean-flying aircraft with no bad vices. It was quite pleasant in the air and handled very similar to the later production articles.’ He added: ‘I recall that the NA-73X was pushed to the side after it had been retired from its last flight. It probably ended up on the company’s junk pile, but I do not recall seeing it there. The NA-73X was a very attractive aircraft and its aluminium skin glowed with constant waxing by George Mountain Bear, an American Indian whose duty was to keep the airframe as clean as possible to pick up those few vital miles per hour.’ Chilton concluded: ‘The “old” NA-73X was no longer representative of the design. We had orders on our hands for hundreds of new [Mustang] fighters and the NA-73X had served its purpose. It had established the trend for what I believe was the finest propeller-driven fighter ever built by any country.’

The USAAF Materiel Command evaluated two NA-73 XP-51 airplanes at Wright Field in Dayton, Ohio, during the autumn and winter of 1941-1942. The first example (41-038) was evaluated for flight test activities while the second airplane (41-039) was used for armament tests. NAA built 322 NA-73 airplanes and the two XP-51s were the fourth and tenth ones of these produced. (NAA via Chris Wamsley)

NAA test pilot Lou Wait completed a successful first flight of the first RAF Mustang Mark I (AG345) on 23 April 1941 out of Mines Field. Two of the 322 NA-73 airplanes ordered, the fourth and tenth ones built, were completed to USAAF standard. They was designated XP-51 and named Mustang. Other names such as ‘Apache’ were considered but the name Mustang chosen by the British was catchy enough to satisfy the USAAF as well.

Head of the British Purchasing Commission, Sir Henry Self, paid a visit to the Inglewood NAA headquarters and the aircraft production facility on 6 May 1941 and was rather pleased with the progress he had witnessed. As one of the most instrumental of all persons who were responsible for the creation of the Mustang, he should have felt proud of himself that day.

On 20 May 1941, Chilton made a successful first flight of the first of two NA-73 XP-51 Mustang airplanes (41-038) from Mines Field.

The first flight of the second XP-51 (41-039) soon followed. Both examples were powered by 1,150 hp Allison V-1710-39 engines spinning three-bladed constant speed 10-ft 6-in.-diameter Curtiss Electric propellers. A maximum level attitude speed attained during NAA flight testing was 382 mph at 13,000 feet.

Mustang Mark I production came to a screeching halt on Wednesday at midnight on 4 June 1941 when some 11,000 NAA employees went on strike for increased wages. Top workers were earning fifty cents per hour and demanded seventy-five cents per hour, increased to eighty-five cents per hour if they were working overtime or more than eight hours per shift.

On 20 June 1941, the US Army Air Corps (USAAC) became the US Army Air Forces (USAAF) to better deal with its growing numbers of branched air forces throughout the US and territories. At this time, the USAAF had seven air forces or branches listed as the First Air Force (1st Air Force or 1AF), Second Air Force (2nd Air Force or 2AF) and so on up to the Seventh Air Force (7th Air Force or 7AF). The number of Air Forces grew during the Second World War to a maximum of twenty, ending up with the Twentieth Air Force (20th Air Force or 20AF). These will be addressed later.

Two NA-101 XP-51B airplanes (41-37352 and 41-37421) were created from two of the 150 NA-91 (P-51) airplanes. These were the first NAA-built Mustangs equipped with Packard-built V-1650-3 Merlin engines. Because of this wholly new propulsive system for these aircraft, the design was initially ordered as the XP-78 but soon reverted to XP-51B. (Rockwell International via Chris Wamsley)

In the meantime, the NAA employee strike raged on in Inglewood and, on 9 June, by presidential order from Franklin D. Roosevelt, the Inglewood factory was overtaken by US Army troops to secure the plant and protect managerial workers who remained on the job. The twenty-seven-day strike was peacefully ended on 1 July and NA-73 Mustang Mark I production resumed. However, deliveries did not start until late August when the RAF accepted two post-strike-built NA-73 airplanes. Only another 136 airplanes were delivered through the remainder of 1941.

During the strike, NAA received a Department of the Army contract (DA-140) on 30 June 1941 on behalf of the BPC for 150 P-51 airplanes under its NA-91 programme. These were to be delivered to the RAF as Mustang Mark IA airplanes, RAF serial numbers FD418 to FD567. By contract, two of these airplanes were to be delivered as XP-51B prototypes. These were the 33rd and 102nd NA-91 airplanes built.

NAA chief engineering test pilot Bob Chilton completed the first flight of the second production Mustang Mark I (AG346) out of Mines Field on 3 July 1941. Between 1 May and 23 May 1941, Chilton flight tested AG345 seventeen times much in part to evaluate ongoing radiator and air scoop performance at different speeds and altitudes. He also made the first flight of AG347 – the third production Mustang Mark I – on 30 July 1941.

On 7 July 1941, NAA began work on its NA-91 programme whereby 150 P-51 Mustang Mark IA airplanes would be built under the new Lend-Lease agreement for the RAF under Department of the Army/USAAC contract DA-AC-140. By agreement, two of these airplanes – 41-37352 and 41-37421 – were to be completed as the two prototype XP-51B airplanes powered by 1,380 hp Packard-built V-1650-3 Merlin engines rather than Allison V-1710 engines. This engine change was the result of the highly successful Mustang Mark X programme in Great Britain (which is discussed in Part 3 under XP-51B).

On 1 August 1941, NAA received two very important visitors from Great Britain. Chilton had just completed functionality tests of AG346 when he was introduced to RAF Squadron Leader Michael N. Crossley, an ace with nine kills, and RAF Wing Commander Christopher Clarkson who were there to complete acceptance testing of AG346. Clarkson had the responsibility of producing pilot’s handbooks for all NAA aircraft built for the RAF.

The first XP-51 airplane (41-038) left Mines Field on 24 August and was ferried to Wright Field for official USAAF performance evaluations. On 19 September 1941, Chilton initiated functional flight tests of AG349 or Mustang Mark I number five: the last NA-73 built with the short carburettor air scoop. This particular airplane was later sent to Russia for evaluation by its air force. In the beginning of October, the RAF accepted its first Mustang Mark I airplane (AG346) at Inglewood, which was subsequently shipped to Great Britain. It arrived at Liverpool on 24 October 1941 and was transported to Boscombe Down for flight trials by the A&AEE.

Performance tests of XP-51 number one (41-038) were flown out of Wright Field from 8 October to 22 December 1941. With a full load of ammunition and 170 gallons of fuel, it weighed 7,934 lb and was clocked at 382 mph at 13,000 feet. NAA had guaranteed 375 mph which was exceeded. Its range was 750 miles at 325 mph cruise speed. During these USAAF evaluation flights on 21 October, Chilton arrived at Wright Field to evaluate a Spitfire Mark V and Hurricane Mark II. While he was there, Chilton checked the log book of the XP-51 and found that only one hour of flight time had been accounted for since its arrival on 24 August. When questioned about it by Chilton, the XP-51 Project Officer, second Lieutenant Winthrop Towner, simply stated: ‘It’s a low priority program and we’re not done testing it.’ Nevertheless, it was flown one more time the following day and subsequently readied for its ferry flight to Langley, Virginia, to be evaluated by NACA.

With four dummy 20-mm cannon installed on AG347, two on either wing, Chilton conducted a series flying tests on 30 October to determine the amount of drag they produced on this Mustang Mark I airplane.

The first Mustang Mark I flight in Great Britain (AG346) occurred on 11 November. The commander of the Air Fighting Development Unit (AFDU) described the airplane as an ‘...excellent low- and medium-altitude fighter ... pleasant to fly ... extremely stable ... far smoother in all manoeuvres than the Spitfire’. Other test pilots said the Mustang was ‘...definitely the best American fighter yet that has reached Great Britain’.

The Morrow Aircraft Corporation Model 1-L Victory Trainer made its first flight in November – the exact date is unknown to this author. So what does this have to do with the Mustang story? In early 1941, Howard B. ‘Spud’ Morrow founded an aircraft manufacturing firm in San Bernardino, California, and set out to find someone to design his idea for a combination military and civilian trainer airplane. NAA vice president Lee Atwood suggested Ed Schmued and Morrow contacted him. An agreement was made and Schmued set about designing the airplane in his own time. The airplane (Civil Registration Number NX-33661) was made entirely of bonded plywood except for its retractable landing gear and engine mount. It featured inward retracting main landing assemblies, and not surprisingly, its wing and tail surfaces closely resembled those of the Mustang. It was dubbed the ‘Little Mustang’ due to its Mustang-like appearance.

The first of 500 A-36A airplanes (42-83663) on the flight line at Mines Field in October 1942. Noteworthy is the barrage balloon in the background. (National Museum of the USAF)

Adolf Hitler, Benito Mussolini and Emperor Hirohito joined forces to terrorise the world during the Second World War. After Italy signed an armistice with the Allies on 3 September 1943, Hitler and Hirohito continued their terrible ways. This 1942 NAA advertisement shows caricatures of these cold-blooded murderers denouncing their aggressive ways and tells of three NAA-built aircraft that would help defeat them: the B-25 Mitchell, AT-6 Texan and the P-51 Mustang. (Author’s collection)

At about 07:45 on 7 December 1941 local time, the Japanese attacked without warning a large number of US Navy Pacific Fleet ships moored in Pearl Harbor, Hawaii, and a number of surrounding military facilities including USAAF airfields. It was 13:45 in Washington, D.C., and on the morning of the next day, Franklin D. Roosevelt announced: ‘Yesterday, December 7, 1941 – a day which will live in infamy – the United States of America was suddenly and deliberately attacked by naval and air forces of the Empire of Japan.’ On that very same day, 8 December 1941, the US declared war on both Japan and Germany. (It is interesting to note that a future chief test pilot for NAA, then a Second Lieutenant flying a P-40B out of Haleiwa airfield, shot down four of the attacking enemy airplanes on that horrific day. His name was George S. ‘Wheaties’ Welch, and as a result of his actions, he was awarded a Distinguished Service Cross. He would shoot down another 12 aircraft flying P-38s of the 5th Air Force for a total of sixteen becoming a triple ace and a Major. He joined NAA in July 1944 after a serious bout with malaria, in time to perform engineering flight tests during the P-51 programme. On 23 April 1945, he made the first flight of the XP-51J. Welch went on to the F-86 Sabre and F-100 Super Sabre programmes only to lose his life on 12 October 1954 while flight testing an early F-100A at Edwards Air Force Base in California. It disintegrated during a high-speed split-s dive from 35,000 feet at about 1.5 Mach number due to insufficient vertical tail area.

The second XP-51 Mustang (USAAF serial number 41-039) was ferried to Wright Field in Dayton, Ohio, where it arrived on 16 December 1941 for USAAF evaluations. This airplane was used primarily for gun firing evaluations.

1942

The USAAF was ill-prepared for all-out aerial combat in the early days of 1942. In fact, its inventory of front line combat aircraft was inadequate to say the least. And as far as P-51 Mustang production for use by the USAAF went, it had not yet begun as Mustangs built at the time were procured by the USAAF and delivered to the RAF as Mustang Mark IAs under the Lend-Lease programme. Meanwhile, RAF Mustang Mark I production and deliveries continued.

RAF colour scheme. (NAA via USAF)

During the month of January 1942, No. 26 Squadron based at RAF Lympne became the first operational squadron to receive Mustang Mark I airplanes. Most of these had an F24 camera installed aft of the pilot’s seat for armed reconnaissance with the Army Cooperation Command. The RAF accepted 84 Mustang Mark Is during this month.

Kindelberger sent a letter to Wright Field on 2 February 1942; its subject line read: Production of P-51 Mustang Fighter Airplanes. In part, this programme update letter stated, ‘...a total of 620 airplanes had been ordered by the RAF at this time. Under the Defense Aid program, 150 additional were ordered by the Army, making a total of 770 aircraft ... approximately 220 airplanes had been delivered and that the production rate is now 78 airplanes per month. Starting about March 1, the production rate will be 104 per month. At this rate the fighters will all be delivered by August 1942 and no additional orders have been 

indicated.’

On 8 February 1942, U-boat U-108 sank British freighter Ocean Venture off Cape Hatteras, Virginia, and most of its crew and the twelve Mustang Mark Is it was transporting were lost. Fourteen survivors were rescued the next day. In another U-boat attack just a few days later, yet a further eight Mustang Mark I airplanes were lost.

The first of two XP-51 airplanes (41-038) was flown from Wright Field to Langley Field in Virginia on 1 March 1942 where it was turned over to the NACA for its flight test evaluations.

On 16 April 1942, NAA initiated its A-36A production programme at Inglewood where it manufactured 500 examples during the last three months of 1942 and the first two months of 1943.

No other Mustangs were built during this time frame. Thus far then, not counting the NA-73X, 1,272 Mustangs had been built.

On 18 April 1942, sixteen B-25B Mitchell bombers employed by the USAAF pulled off a major American morale boosting accomplishment when they were launched from the pitching and rolling deck of USS Hornet to strike Tokyo, Japan, on its main island of Honshu. This ‘pay back’ raid led by Lt. Col. James H. ‘Jimmy’ Doolittle was the first time since Pearl Harbor that the US struck back at the Empire of Japan. The B-25Bs employed came from the 34th, 37th and 95th bomb squadrons and the 89th reconnaissance squadron of the 17th Bomb Group (Medium).

On 24 April 1942, a XB-28 ‘Dragon’ completed a successful first flight out of Mines Field with Edward ‘Ed’ Virgin and Joseph E. ‘Joe’ Barton at the helm. Exactly one later, the same two pilots successfully flight tested the modified XB-28A from the same location. While these occurrences have nothing to do with the Mustang story, it does show that NAA had ‘other irons in the fire’ during its development.

Ronald T. ‘Ronnie’ Harker, Rolls-Royce chief test pilot, flight tested an Allison-powered Mustang Mark I (RAF serial number AG422) at RAF Duxford in Great Britain on 30 April 1942. He sent a letter to R-R the following day suggesting the installation of a Merlin 61 engine in a Mustang to see if it would improve its performance above 15,000 feet which he found to be dismal with the Allison engine.

RAF No. 2 Squadron was first to fly the Mustang Mark I into battle on 10 May 1942 when RAF Flight Officer Graham Newstead Dawson flew a solo tactical reconnaissance mission over northern France. He was promoted to Acting Flight Lieutenant and was shot down and killed on 16 July 1942.

Following Harker’s suggestion, Rolls-Royce general manager Ernest Walter Hives sent a secret memo to the British Air Ministry on 14 May proposing the installation of several Merlin engines in Mustang Mark I airplanes for thorough flight test evaluations. His suggestion was accepted post-haste and on 29 May, the first airplane – a Mustang Mark I (RAF serial number AG518) – was allocated to R-R for the Allison to Merlin engine swap plus associated modifications. The programme was dubbed Mustang Mark X, but this first airplane, a less capable NA-73, was never converted. Instead, an NA-83 Mustang Mark I (RAF serial number AM121) was first to be converted and it made its first flight on 7 June 1942.

Bob Chilton completed a successful test hop in the first P-51 Mustang (USAAF serial number 41-37320, RAF serial number FD418) from Mines Field on 30 May 1942. These would be Mustang Mark IA airplanes for the RAF. Later that day, he performed dive brake tests on a modified NA-73 – the first one built for the upcoming A-36 programme. This first P-51 airplane (41-37320) was retained by the USAAF and two F-24 cameras were installed. It was re-designated P-51-1-NA and essentially served as the prototype F-6 tactical reconnaissance version of the Mustang. In fact, it was again re-designated to F-6A.

On 12 June 1942, the USAAF Materiel Command authorised its own Merlin engine-powered project after witnessing the most promising Rolls-Royce efforts in Great Britain. With this, it issued the designation MX-278 to the secret project and ordered two prototypes designated XP-78 (MX meaning Materiel, Experimental).

NAA initiated its NA-99 programme on 23 June for the manufacture of 150 P-51A (Mustang Mark II) airplanes in Inglewood.

Again using the company-owned number one NA-73 airplane, modified with A-36 type bomb shackles, Chilton performed initial seventy-five-US gallon drop tank tests on 4 July.

The very first loss of a Mustang in combat occurred during a high-speed ground target strafing pass on 14 July. As reported, this Mustang Mark I had flown straight in to the ground. The reason for this remains unclear.

An Army Air Forces Technical Report entitled Final Report of Inspection, Performance and Acceptance of NAA Model XP-51 (Report No. 4801) was released on 15 July 1942. In part this report stated:

This airplane was developed by the contractor primarily for sale to the British government. 

     On 4 May 1940, North American Aviation, Inc. signed a Foreign Release Agreement with the Army Air Forces for the foreign sale of the model NA-73 airplane that entitled the Army Air Forces to two airplanes of the type contemplated for sale. This release specifically set forth that the Army Air Forces would receive the fourth and tenth articles from the [NA-73] production line. The engines, propellers and other normal items of regular government furnished equipment [GFE] specified for Army Air Forces airplanes were specified as GFE for these two airplanes. There were no provisions made for mock-up or 689 engineering inspection of these two airplanes although arrangements were made for process inspection and flight testing of the first [NA-73X] airplane by Army Air Forces personnel. Following the completion of negotiations between North American Aviation, Inc. and the Anglo-French Purchasing Commission, Authority for Purchase No. 165265 for two XP-51 airplanes was initiated on 24 July 1940 and followed by a contract which was approved by the Assistant Secretary of War on 20 September 1940. The airplanes were built in accordance with the British Model Specifications except that certain modifications were made to accommodate standard Army Air Forces equipment. 

     Except for minor incidental changes, the project progressed at a normal rate. On 24 February 1942, an Engineering Order was issued to leave the original hydraulic gun charger equipment out of both airplanes and install in lieu thereof, fully automatic gun charger equipment which was being developed by the Bendix Corporation [for installation] in the second airplane. This was done so that the new charging equipment could be flight tested at an early date. Since the delivery date of the automatic hydraulic chargers was such that a delay in delivery of the airplane would result from the installation, it was decided that provision only would be made for the installation of this equipment. 

     Preliminary flight testing was conducted on the first [NA-73X] airplane at the contractor’s plant by the contractor’s personnel and government pilots in accordance with the terms of the contract. Considerable trouble was incurred with the Allison [V-1710-F3R] engine installation in the early stages of the airplane development. At one particular throttle setting the engine was found to be extremely rough and in one instance the engine completely cut out resulting in a forced landing in a plowed field [on 20 November 1940]. This landing was made by the contractor’s pilot [Paul Balfour] without damage to property or personal injury, although considerable damage was done to the [NA73X] airplane. 

     Although no mock-up or 689 engineering inspection was made, a preliminary flutter and vibration survey was made by Army Air Forces personnel prior to any flights by Army Air Forces pilots. 

     Under the terms of the contract the Army Air Forces were supposed to receive the fourth and tenth [NA-73] production articles. These airplanes were scheduled for delivery in February and March of 1941. The production of the NA-73 airplanes was delayed both by the crash-landing of the experimental [NA-73X] model and the delay of engine deliveries for the British airplanes. To facilitate the delivery of the XP-51 models it was decided to take the fourth and tenth articles from their place in the assembly line and install the Army Air Forces [V-1710-39] engines in them for delivery to Wright Field. This procedure was followed and the first airplane was accepted at the plant of the contractor and flown to Wright Field on 24 August 1941, for the purpose of conducting official performance tests. The second airplane was accepted and flown to Wright Field on 16 December 1941. 

     Upon arrival of the first airplane at Wright Field, a safety inspection was conducted. The airplane was next weighed and ballasted and an actual weight and balance report was prepared. Before flight testing could be conducted, it was necessary to install backfire screens to prevent damage to the airplane due to engine backfiring. This work took considerably longer than was anticipated due to the breaking off of studs. It was also necessary to install new aileron and flap bracket bolts to correct an unsatisfactory condition found by NAA on other NA-73 airplanes. The replacement parts were furnished by the contractor and installed by Army Air Forces personnel under the supervision of the contractor’s representative. 

     The contractor conducted flight tests on early production NA-73 airplanes and on the two XP-51 airplanes subsequently delivered to Wright Field. It was during flight testing of the first XP-51 airplane that it was discovered that engine difficulties previously encountered could be overcome by increasing the length of the ramming air intake scoop. It was only after the contractor considered the airplanes to be satisfactory, that they were turned over to the Army Air Forces. 

     Preliminary performance tests were conducted at the contractor’s plant by personnel on the contractor’s first [NA-73] article during March of 1941. Final official performance flight tests were conducted at Wright Field between 8 October and 22 December 1941. The reason for the long delay of [XP-51 number one] flight testing was due to the higher priority of other airplanes to be tested, bad weather and malfunctioning of the coolant scoop control and landing gear retraction mechanism during cold weather. These difficulties and others of a minor nature were corrected by Army Air Forces personnel and the contractor’s representatives. 

     The second [XP-51] airplane was thoroughly inspected by the Flying Branch after delivery and was then turned over to the Armament Laboratory for gun firing tests.

Initial dive bombing flight tests were conducted at the Muroc Army Air Field bombardment and gunnery range about 100 miles northeast of Los Angeles by Bob Chilton on 18 July. He was flying a modified Mustang Mark I (NA-73 number one) temporarily fitted with A-36 type speed brakes and bomb shackles. On the same day, for the upcoming XB-51B flight test programme, a four-bladed propeller was evaluated on a Mustang Mark I (RAF serial number AL975).

NAA commenced its NA-101 programme on 25 July to produce two Merlin engine-powered XP-51B airplanes. To do this, it set aside two NA-91 P-51 (Mustang Mark IA) airplanes for this project. These two airplanes were initially designated XP-78, but since the engine swap was the only ‘real’ difference, the airplanes were designated XP-51B instead. The two NA-91 airplanes used for this programme were 41-37352 and 41-37421; NAA factory serial numbers 91-12013 and 91-12082.

The first aerial victory recorded by a Mustang came on 19 August 1942 when a Fw 190 was shot down by a Mustang Mark I over Dieppe, France. This Mustang of No. 44 Squadron (Canadian) was flown by Pilot Officer Hollis H. Hills from Pasadena, California, who had joined the Royal Canadian Air Force prior to America’s entry into the war.

Production of the A-36A light attack dive bomber was well underway when the USAAF contract for 500 production airplanes was officially approved on 21 August 1942. Just a little more than a month later the first flight of the A-36A Mustang (USAAF serial number 42-83663) was successfully made on 21 September out of Mines Field with Bob Chilton at the controls.

Even before the first XP-51B took to the skies, NAA undertook its NA-102 programme on 26 August to set into motion its P-51B production programme at Inglewood. This was followed by its NA-103 programme on 8 October to produce P-51C airplanes at its Dallas, Texas, plant.

The first operational USAAF Mustang was the NA-91 P-51 of which 150 examples were built. They were all delivered to the RAF, but with the advent of Pearl Harbor, a large number were retained by the USAAF. (National Museum of the USAF)

Two modified NA-91 P-51 Mustangs were used to create two experimental XP-51B airplanes (41-37352 and 41-37421) under NAA Charge Number NA-101. These were the 33rd and 102nd NA-91 airplanes built. The second XP-51B is shown here. (NAA via Peter M. Bowers)

Rolls-Royce chief test pilot Ronald Thomas Shepherd, a former Captain in the Royal Flying Corps (RFC), undertook the first flight test of a Merlin-powered Mustang – a Mustang Mark I (RAF serial number AL975/G) – on 13 October 1942, thereby initiating the Mustang Mark X flight test programme. (The suffix ‘G’ meant that this was a top secret airplane that had to be closely guarded at all times.)

German airspace was penetrated for the first time by a Mustang when four Mark I airplanes of No. 268 Squadron flew from its RAF base at Bury St. Edmunds in Great Britain into Germany and back on 21 October. These aircraft were performing tactical reconnaissance to mark future bombardment targets.

This high mission A-36A (42-84067) sits at the ready with two 500 lb bombs attached while four unidentified men pose with her. (National Museum of the USAF)

The first flight of the second Mustang Mark X (AM208) was successfully concluded on 13 November. It was piloted by Shepherd.

NAA chief engineering test pilot Bob Chilton performed a successful first flight on 30 November 1942 with the very first Merlin engine-powered XP-51B (USAAF serial number 41-37352). Following this flight, a redesigned radiator water cooling scoop and duct optimised to eliminate boundary layer rumble was installed. On 4 December, Chilton performed a functional flight test on this XP-51B and it was deemed a complete success.

1943

During October, November and December 1942, no P-51 Mustang or Mustang Mark I/IA deliveries were made: sixty were delivered in September 1942. This carried on through January and February 1943 with seventy delivered in March 1943. It was during these five months that A-36A production was given top priority and they were the only Mustang airplanes produced in Inglewood during this time.

Several new and interesting types of Mustangs were created in 1943. One variety in particular, designated P-51D, was to become a legend and remains as one of the most popular warbirds of all time. Under NAA Charge Numbers NA-105, NA-105A and NA-105B, the Lightweight Mustang programme began on 2 January 1943 at Inglewood. By USAAF contract, there would be seven of these aircraft built: three XP-51Gs, two XP-51Fs and two XP-51Js. These would be similar to the other Lightweight Mustang, the forthcoming P-51H, but with a number of differences. This programme was classified secret by the USAAF Materiel Command that assigned its MX-356 designation to it. The F would be powered by the Packard-built V-1650-3 Merlin engine; the G by the Rolls-Rolls RM 14SM (Merlin 100); and the J by the Allison V-1710-119 engine with a two-stage blower. The second XP-51B was initially and successfully flown by Chilton from Mines Field on 2 February 1943. The USAAF Materiel Command Secret Project MX-278 had been assigned to the XP-78 cum XP-51B programme.

The first Dallas, Texas-built Mustangs were NA-103 P-51C-1-NTs, P-51C-5-NTs and P-51C-10-NTs. This is a P-51C-5-NT (42-103695) of the 14th Air Force, 528th Fighter Squadron, 311th Fighter Group, based at Shwangliu, China, in the CBI flying near ‘The Hump’ c. September 1944. (National Museum of the USAF)

The maximum speed of the A-36A was 365 mph in level attitude flight and increased to well over 400 mph when it was in a 60-70 degree dive. Shown here is the 409th of 500 A-36A (42-84071) airplanes that were produced. (National Museum of the USAF)

On the following day, Chilton completed a successful flight of the first P-51A (43-6003) from Mines Field. It was retained for a time by NAA for ongoing evaluations while the second example (43-6004) was delivered to Wright Field. This airplane was nicknamed ‘Slick Chick’ due to its lack of installed armament.

Two NA-105A XP-51G airplanes were built (43-43335 and 43-43336). These were originally fitted with five-bladed Rotol Airscrews propellers manufactured in Great Britain. These were electric constant speed propellers of which its blades were made of laminated wood. These propellers did not work well with the XP-51G aircraft and were soon replaced with four-bladed props. The XP-51G airplanes were powered by special Rolls-Royce RM 14.SM Merlin engines. (San Diego Air & Space Museum via John Melson)

Chilton successfully completed the first flight of the P-51D prototype out of Mines Field on 27 February 1943. It was a modified P-51B-1-NA (43-12102). This airplane has been referred to as the XP-51D, but this author cannot find official documentation that proves this albeit it would be appropriate. It is also believed that a second prototype P-51D (43-12101) – from another P-51B-1-NA – was also created, but again, no official documentation can be found.

During March 1943, a single A-36A airplane (42-83685) was delivered to Great Britain for evaluations by the RAF. It was assigned RAF serial number EW998. Also, more importantly, combat operations for the A-36A began in North Africa.

Edgar Schmued, designer of the Mustang who had been in Great Britain since mid-February with a team of hand-picked aeronautical engineers, returned to Inglewood in mid-April. During his two months away, he and his co-workers had thoroughly investigated Spitfire weights and balances at Supermarine headquarters. He wanted to know how the Spitfire could be lighter than the Mustang given that it was of a similar size. Schmued also made arrangements with Rolls-Royce for the delivery of two Merlin 100 (RM 14SM) engines for the XP-51G airplanes.

The first USAAF Mustang, a P-51-2-NA (41-37328), later designated F-6A, was used in combat on 9 April 1943 in the MTO. It was flown by Lt Alfred Schwab of 12th Air Force, 68th Observation Group, 154th Observation Squadron, based in North Africa. He flew a tactical reconnaissance sortie over Tunisia.

NAA assigned its NA-106 Charge Number to the P-51D programme on 1 May 1943. Two P-51B-10-NA airplanes (42-106539 and 42-106540) were set aside for modification to the P-51D configuration.

On 5 May 1943, the first production P-51B-1-NA (43-12093) was flight tested at Mines Field. It subsequently was ferried to Wright Field where it established official Merlin-powered P-51B performance figures.

The first of two XP-51B airplanes (41-37352) was ferried to Wright Field on 20 May for additional evaluations.

Equipped with A-36A light attack Mustangs, the 27th and 86th Fighter-Bomber Groups initiated attacks upon German and Italian air bases in Italy for the first time on 6 June 1943.

NAA initiated its NA-105 programme to build seven Lightweight Mustang prototypes: three XP-51Fs (43-43332/-43334), two XP-51Gs (43-43335 and 43-43336) and two XP-51Js (43-7027 and 43-76028). Two of these airplanes were cancelled and were temporarily assigned USAAF serial numbers 43-43337 and 43-43338, believed to be two cancelled XP-51Hs or XP-51Js.

On 21-22 July 1943, a number of A-36As fitted with seventy-five-US gallon drop tanks escorted B-26 Marauder medium bombers to targets in Italy. This was a record-setting mission for single-engine aircraft as they flew a round trip of over 800 miles.

NAA almost lost its chief engineering test pilot Bob Chilton on 4 August 1943 when he and NAA flight test engineer Roy Ferrin were forced to bale out of their stricken XB-28A while flying rolling manoeuvres over the Pacific Ocean just west of Balboa, California. The airplane had suffered a structural failure, but both men were rescued by the US Coast Guard.

This A-36A named ‘Doodle’ was based at Paestum, Italy, when this picture was taken in 1943. From left to right are Lt. Sefton, Flight Officer R. L. Bryant (his plane at the time) and an unknown man. According to the mission markings, ‘Doodle’ had flown 36 attack missions. This is F/O Bryant’s personal plane (note the stencilling to the right near where he is sitting on the wing). (National Museum of the USAF)

Benito Mussolini had been thrown out of office and imprisoned, and the new Italian Government surrendered to the US and Great Britain on 3 September 1943. The Italian Government further agreed to join the Allied Forces. The Germans took control of the Italian Army, freed Mussolini from imprisonment and set him up as the head of a puppet government in northern Italy. This blocked any further Allied advance through northern Italy. (Benito Mussolini was later recaptured while attempting to flee to Switzerland and subsequently executed with his mistress, Clara Petacci, near Lake Como as a hated war criminal by Italian partisans on 28 April 1945.)

The P-51A entered service with the 14th Air Force in China on 14 September. The P-51As primarily served as fighter-bombers but also as bomber escorts while they were based in China.

The 311th Fighter-Bomber Group (Single Engine) of the Tenth Air Force equipped with two squadrons of A-36As and one squadron of P-51As began operations at Dinjan Airfield, India, and it was the first Mustang-equipped group to see combat against the Japanese on 16 October 1943.

During October, the USAAF accepted a grand total of 382 Mustangs from Inglewood and Dallas production lines. This was the highest one month total of deliveries since Mustang production had begun.

P-51B-5-NA (43-6855) of 8AF, 55FS, 20FG, RAF Kings Cliffe. Unfortunately, this airplane does not sport a pilot’s name or a nickname so it remains unclear as to who is in the cockpit. (Stan Piet)

The first USAAF P-51B Mustangs began to arrive in the ETO at RAF Boxted on 16 November. They were initially assigned to the 9th Air Force, 354th Fighter Group. Comprised of the 353rd, 355th and 356th Fighter Squadrons it was dubbed the Pioneer Mustang Group since it was the first unit to get P-51Bs in the ETO. The 357th FG of the 9th AF was second to get P-51Bs.

On 17 November, flying out of Mines Field, Chilton successfully completed the maiden flight of the first service test P-51D. It and the second service test example were powered by Packard-built V-1650-3 Merlin engines spinning four-bladed propellers. These two airplanes were created from two P-51B-10-NA airplanes (42-106539 and 42-106540), the 111th and 112th P-51B-10-NA airplanes, under NAA Charge Number NA-106. As built, they featured the large bubble-type canopy tested earlier on a P-51B-1-NA (43-12102). They also lacked the eighty-five-gallon fuel tank installed behind their cockpits, their wings were moved slightly forward, they came with six wing-mounted .50 calibre machine guns in lieu of four, and a Type D-2 pitot tube with flush static vents in lieu of the Type G-2 airspeed tube. With this inaugural test flight, the most famed version of all Mustangs produced had been born. (Most service test airplanes have the Y for service test prefix but these two P-51Ds did not. Thus they were not designated YP-51D.)

By an official USAAF Materiel Command communication to NAA, it was authorised that a new eighty-five-gallon fuselage fuel tank be installed within the factory to all Inglewood-built P-51B-10-NA and Dallas-built P-51C-3-NT aircraft and subsequent P-51B/C airplanes. To accommodate this fuel tank, components of the radio equipment were installed further aft in the fuselage just forward of the tail wheel bay.

On 1 December 1943, the 354th Fighter Group of the Ninth Air Force flew its first combat sortie from RAF Boxted. On this very same day the Eighth Air Force received its first P-51B Mustangs. The Eighth Air Force – the largest user of P-51 Mustangs in the Second World War – began its combat operations over Europe on 13 December 1943. By VE Day, 8AF had fifteen combat fighter groups, two fighter training groups and a few other specialised squadrons equipped primarily with P-51Bs, P-51Cs, P-51Ds and P-51Ks during its tenure in the ETO.

On 19 December, the 357th Fighter Group, the Yoxford Boys of the Ninth Air Force, received its first Mustangs: P-51Bs at RAF Yoxford.

The RAF sent one of its first Mustang Mark III (FZ107) airplanes, a P-51B-5-NA (43-6407), for a full evaluation at its Air Fighting Development Unit (AFDU) at RAF Wittering on 26 December 1943.

The Tuskegee Airmen received new P-51D Mustangs in mid-1944 after flying numerous P-51B and P-51C hand-me-downs from units other than those of their own. (US Air Force)

This specialised unit had the responsibility of evaluating all new aircraft types – domestic and American types – including captured enemy aircraft. After its thorough evaluation of this particular airplane, the AFDU concluded on 8 March 1944 that it was superior to the Spitfire Mark IX, Spitfire Mark XIV, Tempest Mark V, Fw 190 and the Bf 109G – all of which were the latest versions of these standout British and German fighters. When the AFDU tested captured German aircraft it was known as the ‘Rafwaffe’.

1944

1944 was pivotal throughout the CBI, ETO, MTO and PTO. It was when the Japanese lost their home islands on which the new B-29 strategic bomber and the Very Long Range (VLR) P-51 bomber escort fighters could be based. It was also the year when France and Germany were invaded by the Allied Forces. The MTO became another launch point for B-17 and B-24 heavy bombers, and the Japanese within the CBI came more and more under attack.

General James H. ‘Jimmy’ Doolittle replaced General Ira C. Eaker as commander of the 8th Air Force on 6 January 1944.

US Army Air Forces Commanding General Henry H. ‘Hap’ Arnold visited NAA’s Inglewood plant on 7 January 1944 to see first-hand what the ‘Twin Mustang’ was all about. A long-time advocate of fighters that could fly long-range missions in support of strategic bombardment aircraft, who was well aware of the P-51 Mustang’s extraordinary range, he surmised that this aircraft would be able to escort 20th Air Force B-29s on Very Long Range or VLR missions to Japan and back. He therefore gave NAA the ‘green light’ on its NA-120 programme and the prototype Twin Mustang programme was born. Four XP-82 examples were ordered but the order was soon reduced to two examples. The two cancelled XP-82s were resuscitated later, however, to be completed as XP-82A airplanes.

Major James H. Howard of the 356th Fighter Squadron, 354th Fighter Group 9th Air Force, was flying P-51B-5-NA (43-6315) (‘Ding Hao!’) and single-handedly defended a stricken B-17 that was undergoing multiple attacks from Luftwaffe fighters. A former Flying Tiger, Col. Howard was awarded the Congressional Medal of Honor on 5 June 1944 for his valour during his earlier mission on 11 January 1944.

The 357th Fighter Group of the 8th Air Force flew its new P-51Bs into combat for the first time on 14 January 1944.

The premier Lightweight Mustang made its debut on 14 February when Bob Chilton successfully gave the first of three XP-51F airplanes (43-43332) a one hour test hop out of Mines Field.

The first long-range bomber escort mission to Berlin and back was flown by 121 8th and 9th Air Force P-51 Mustangs on 4-5 March. These Mustangs, in addition to eighty-six P-38s and 563 P-47s, escorted 502 B-17s. Of the 121 P-51s launched, sixteen were lost, one was damaged beyond repair and another was damaged. One pilot was KIA and another fifteen were MIA.

On 8 March, NAA initiated its NA-123 programme for the production of eighteen P-82B, one P-82C and one P-82D Twin Mustang aircraft. The P-82C and P-82D airplanes would be completed as radar-equipped night fighter aircraft while the P-82B would serve as long-range fighter aircraft.

Ed Schmued filed for a US patent as inventor on his design of the P-82 Twin Mustang on 31 March 1944. His patent was approved on 4 June 1946.

The 15th Air Force in the MTO received its first P-51B airplanes on 2 April. These were allocated to the 31st Fighter Group – its 307th and 308th Fighter Squadrons based in Italy.

NAA Charge Number NA-126 was established to officially begin the P-51H Lightweight Mustang production programme at Inglewood on 26 April 1944. As the Lightweight Fighter version of the Mustang that went into production, it remains unclear as to why there were no XP-51H airplanes built to precede these aircraft.

On 29 April, the first Commonwealth Aircraft Corporation-assembled Mustang, the Model CA-17 designated Mk.17, made its first flight in Australia. It was created from a previously unassembled RAF P-51D-5-NA (Mustang Mark IV). It was allocated Royal Australian Air Force serial number A68-1001. At this time, CAC was receiving 100 crated P-51D-1-NA airplanes for its CA-17 programme. CAC built eighty production CA-17s and the twenty other NA-110 P-51Ds remained crated and unassembled to be used as spares.

The first flight of the third XP-51F (43-43334) was made by Bob Chilton on 20 May 1944 out of Mines Field. Two days later he completed the first flight on XP-51F number two (44-43333).

The Second World War continued its relentless wrath over most of the globe throughout 1944. But it was during this year that a few key operations, namely Matterhorn, Overlord and Neptune, began to slowly but surely dismantle the war machines of Germany and Japan.

Between March and June 1944, the RAF received six former 12th Air Force A-36A airplanes for the purpose of reconnaissance in the MTO. These were assigned to RAF 1436 Strategic Reconnaissance Flight.

Operation Matterhorn – the strategic bombardment of Japan by B-29s – was initiated on 15 June 1944 when XX Bomber Command commander, Major General Kenneth B. Wolfe, launched sixty-eight B-29s that bombed the Yawata Steel Works. This was the first bombardment of the Japanese homeland since the Doolittle Raid on 18 April 1942. Since the Mustang had demonstrated its long legs in Europe, it was called upon to escort the B-29s. After the island of Iwo Jima was captured in February 1945, it became home to two P-51 fighter groups, the 21st and the 506th, whose primary purpose was to escort the B-29s.

Operation Overlord, the Allied invasion of north-western Europe coincided with Operation Neptune, better known as D-Day which commenced on 6 June 1944.

Number 112 Squadron of the RAF began converting to the Mustang Mark III on 24 June 1944. Flight Officer Leonard Henry ‘Len’ Cherry was the first pilot of No. 112 Squadron to fly a Mustang Mark III, which he did some four months earlier on 16 February 1944. Some of the Mustang Mark IIIs of No. 112 Squadron were transferred to No. 249 Squadron.

In a test of maximum range, after a 1,470-mile flight from a south-eastern air base in Great Britain, sixty-five Mustangs landed in Russia on 21 June. They subsequently returned to Great Britain.

On 30 June, the third of three XP-51F airplanes was shipped to Great Britain for RAF Fighter Command evaluations.

As of 24 July 1944, the 15th Air Force in the MTO had four of its seven fighter groups fully equipped with Mustangs as had been planned.

The RAF received 274 P-51B and 626 P-51C airplanes to complete its fleet of 900 Mustang Mark III airplanes.

NAA test pilot Ed Virgin completed the first flight of the number one XP-51G (43-43335) at Mines Field on 9 August. (Other sources claim 9 August by Joe Barton and 12 August by Bob Chilton. The actual date remains to be verified by official documentation.)

During October 1944, the computing K-14 gunsight was incorporated into P-51D-20-NA Mustangs and in all subsequent block numbers of the P-51D.

The second XP-51G (43-43336) was initially flight tested on 14 November by NAA test pilot Joe Barton.

The vastly increasing number of military aircraft produced in the US during 1944 was nothing less than astounding. It was also the highest production year for the Mustang as NAA turned out no fewer than 6,900 P-51 airplanes from its Inglewood and Dallas production facilities.

‘El Matador’, an A-36A in Sicily in 1943. Flight Officer R.L. Bryant (foot on tyre) flew this A-36A as well as the A-36A named ‘Doodle’. Standing alongside is Bryant’s crew chief, Sgt Dan Perry. (National Museum of the USAF)

1945

When 1945 began, no one knew with any certainty when or if the Third Reich would surrender. As far as Japan, most believed that its final capitulation was a long way off, well into 1946 or even 1947. Because the war with Japan was expected to last much longer, two-part invasion plans were scheduled for late 1945 and early 1946 in two ambitious operations codenamed Olympic and Coronet. These operations – under their parent operation called Downfall, the Invasion of Japan – were eventually scheduled to begin on 1 November 1945 and 1 March 1946.

However, in early 1945, these plans were just coming to fruition. The war against Germany and Japan was still very much at the forefront, but there was a top secret programme underway that very few were privy to: a programme, if successful, that might change everything. Several years earlier, the highly classified Manhattan Project got underway whereby a new and devastating weapon was being developed for delivery by a B-29. To do this in part, under licence from the Boeing Airplane Company, a number of special purpose B-29s were built by the Glenn L. Martin Company in Omaha, Nebraska, under Project Silverplate. These special purpose B-29s featured modified bomb bays that would be able to carry and deliver these special stores. They were powered by more reliable fuel-injected engines and they were lighter than standard B-29s as they were built without the two upper and two lower gun turrets, and came with tail guns only for defence.

In the ETO, both day and night when weather permitted, many hundreds of American and British bombers continued to pound strategic targets in Nazi Germany. And since the Mustang was the preferred escort fighter, both USAAF and RAF Mustangs were at their sides. When these Mustangs were not deperately needed, they were strafing targets of opportunity such as trains and aircraft on the ground. The Mustangs held their own in combat against the Luftwaffe’s Bf 109s, Bf 110s, Me 410s, Me 262s and Fw 190s that attempted to devastate the bomber streams with increasingly effective cannon and rocket attacks. The Mustang’s limited aerial encounters with the advanced turbojet-powered fighter, the Me 262, was respectable given that the Me 262 was around 100 mph faster than the latest P-51D/K aircraft.

RAF Flight Lieutenant A. Mercer was credited with the last confirmed kill of a Luftwaffe aircraft by an Allison-powered Mustang on 1 January 1945. He was flying a Mustang Mark IA (RAF serial number FD560) during Operation Bodenplatte near Zeist, the Netherlands, when he downed a Junkers 

Ju 88.

On 11 January, Captain William Arthur (Bill) Shomo of the 5th Air Force in the Pacific, specifically the 71st Tactical Reconnaissance Group, 82nd Tactical Reconnaissance Squadron, while flying his F-6D-10-NA (44-14841) appropriately named ‘Flying Undertaker’, shot down seven Japanese aircraft to become an ‘Ace in a Day’ and then some. Based at Hill Field, Mindoro, he was later awarded the Congressional Medal of Honor for his actions. He had downed six Ki-61 ‘Tony’ fighters and one G4M ‘Betty’bomber on that historic day.

RAF No. 112 Squadron converted from Mustangs Mark III to Mustangs Mark IV and IVA airplanes in February 1945 and by May, was based in Cervia, Italy. It employed a mixture of IVs and IVAs throughout the remainder of 1945 and into 1946. Eventually, the RAF acquired 281 Mark IVs and 594 Mark IVAs for a total of 875 P-51D and P-51K types.

As of 31 January 1945, the 8th Air Force, duty-bound to field fifteen long-range bomber escort groups solely equipped with P-51s, met its goal.

The premier P-51H Mustang (44-64160) accomplished a successful first flight at Inglewood on 3 February with Bob Chilton at the controls.

NAA’s Dallas plant began production of its P-51D airplanes during March. Due to its high demand, the P-51D was the only version of the Mustang produced at both the Dallas and Inglewood aircraft production facilities.

For the first time, Iwo Jima-based 7th Fighter Command Mustangs began operations over Japan on 7 April 1945 when they flew their first Very Long Range/VLR mission escorting B-29s to Tokyo. Newly acquired P-51 Mustangs of 7th Fighter Command, 15th Fighter Group and its three fighter squadrons – the 45th , 47th and 78th – began to arrive on Iwo Jima on 6 March 1945 when the commander of 7 FC, Brigadier General Ernest M. ‘Mickey’ Moore, landed the first Mustang on the island. The Sunsetters, as 7 FC was nicknamed, had two more groups that soon followed the 15th. The 21st Fighter Group, 46th, 72nd and 531st Fighter Squadrons, began to arrive on Iwo Jima on 17 March. The 506th Fighter Group was the third and last Mustang-equipped fighter group to base itself on Iwo Jima in mid-May 1945. It was comprised of the 457th, 458th and 462nd Fighter Squadrons. It would be these three fighter groups of 7 FC, 20th Air Force, that would be ‘the little friends’ escorting B-29s to Japan. On 7 April 1945, a force of eighty Mustangs flew their first B-29 escort mission from Iwo Jima to Tokyo and back. These P-51s shot down twenty-one enemy aircraft with the loss of only one Mustang. There were numerous subsequent escort missions for the B-29s from the captured islands of Guam, Saipan and Tinian. The B-29s also navigated for the Mustangs before late model P-51D-30--NT Mustangs were fitted with the much improved Uncle Dog/Brother Agate navigation system featuring twin radio antennas. The Uncle Dog/Brother Agate antennas worked in conjunction with the four-channel SCR-522 ultra-high frequency (UHF) radio.

NAA test pilot Joe Barton successfully flight tested the first of two XP-51J Lightweight Mustang prototypes on 23 April. Welch had recently joined NAA to serve as one of its engineering test pilots.

Hitler committed suicide on 30 April 1945 during the Battle of Berlin. The surrender of Germany quickly followed and was authorised by Hitler’s replacement, President of Germany, Karl Dönitz, leader of the new Flensburg Government. It was on 8 May 1945 when the Allies formally accepted the unconditional surrender of the armed forces of Nazi Germany and the end of Hitler’s Third Reich. Victory in Europe Day or VE Day had finally arrived for the persevering Allied forces.

During April 1944, NAA undertook an in-house programme to evaluate the use of added propulsion to a factory-fresh P-51D-25-NA (44-73099). To do this, with assistance from the Aerojet Engineering Corporation, founded 19 March 1942 in Azusa, California, NAA procured a small rocket motor of around 1,300 lb of thrust (continuous for about one minute) fuelled by aniline (sixty-five per cent) and furfuryl alcohol (thirty-five per cent) carried in non-jettisonable under-wing tanks on the inboard stores attachment points. The left tank held about 330 lb of red fuming nitric acid while the right tank held about 125 lb of the aniline-alcohol mixture with 27 lb of nitrogen gas. A second P-51D-25-NA (44-74050) was fitted with a smaller two-minute duration 690 lb thrust rocket motor. This programme was referred to as ‘Flash Performance of the P-51D Equipped with Acid Aniline Rocket Motor.’ The two airplanes were later evaluated by The Air Proving Ground Command at Eglin Field in Florida. It was determined that the centre of gravity (cg) shift caused by the weight of the rocket motors was unacceptable and the plan to incorporate these rocket motors in the field was abandoned. The first test firing in Inglewood was held about one month before VE Day with 44-73099 while the second with 44-74050 came about two months later. Both airplanes were subsequently ferried to Eglin Field for USAAF evaluations.

Captain William Arthur ‘Bill’ Shomo is credited with scoring eight kills flying an F-6D – seven in one day and the most kills of any Mustang pilot during the Second World War. Shomo’s first kill was on 9 January 1945, and two days later, he claimed seven kills in a day which earned him the Congressional Medal of Honor. Shomo is shown seated in the cockpit of his F-6D-10-NA (44-14841) named ‘Snooks 5’ with the eight kills he earned. He belonged to the 71TRG, 82TRS. (USAF)

In the Pacific, however, the end of the Second World War was not in the foreseeable future. The Japanese Government had instilled a ‘fight to the death’ philosophy and this is exactly what their armed forces were doing. Even though 20th Air Force B-29s were burning tens of Japanese cities to the ground with their relentless fire bombardment raids, the Japanese refused to surrender.

The tremendous range being demonstrated by the Mustang in Europe while escorting B-17s and B-24s called for its presence in the Pacific to escort the B-29s that were pounding Japan. Even with their astounding range, they had to be based as close to Japan as possible. It was therefore imperative that the island of Iwo Jima be invaded, captured and secured. On 19 February 1945, parts of three US Marine Corps divisions landed on Iwo Jima for the start of one of the bloodiest battles of the Second World War. More than 4,500 Marines were killed and around 19,000 wounded in the taking of Iwo Jima, and on 16 March, the island was declared secure. However, of the some 21,000 Japanese soldiers defending the island, around 350 to 400 remained hidden in underground caves. They attacked on 27 March killing many Mustang personnel but most of the defenders were killed as a consequence. However, even before this subsequent battle, a large number of Mustangs were already based on the island.

The last Luftwaffe aircraft to be shot down in the ETO was downed by an F-6C photo-recce Mustang on 8 May 1945, recognised as VE Day.

The premier XP-82 was ready for its first flight on 16 June 1945, but it refused to take off. NAA test pilot, Joseph F. ‘Joe’ Barton, made several take-off attempts but the tail wheels seemed magnetised to the runway: they would slightly lift, then drop back on to the runway. Finally, on 23 June, it flew after the problem was found and cured.

An unidentified F-6C (42-103xxx), formerly a P-51C-5-NA, named ‘Big Mamma’ of the 111TRS. (USAF)

The last operational Allison-powered Mustang, a RAF Mustang Mark II of No. 268 Squadron, returned to Great Britain from its base at Hustedt in Germany on 7 July.

On 16 July 1945, in Alamogordo, New Mexico, a test called Trinity took place whereby the world’s first atomic bomb exploded. The Manhattan Project had spawned the deadliest weapon known to mankind and wheels were set in motion to get several of these bombs to the 20th Air Force in the Mariana Islands, namely the island of Tinian where the Silverplate B-29s were based. Two different types of atomic bombs were partially assembled for their shipments to Tinian. These two bombs named ‘Little Boy’, a gun-type uranium bomb, and ‘Fat Man’, an implosion-type plutonium bomb, were delivered to Tinian in different ways. ‘Little Boy’ bomb units, accompanied by the U-235 projectile, were shipped out of San Francisco to Tinian aboard USS Indianapolis on 16 July 1945, arriving 26 July. ‘Fat Man’ components were delivered by both a B-29 and a C-54 transport. Both bombs were assembled but unarmed by 30 July. The official order from Washington, D.C. gave its go-ahead schedule for on or about 3 August 1945.

On 6 and 9 August 1945 respectively, two B-29s, the ‘Enola Gay’ and ‘Bockscar’, dropped two atomic bombs on Hiroshima and Nagasaki. Both cities were obliterated with a huge loss of life totalling some 110,000 persons killed with as many as 130,000 injured. The Japanese Government was slow to capitulate and strategic bombardment continued as well as the VLR P-51 Mustang escort missions. The Mustangs travelled an average of 1,500 miles made possible in part by their 165-gallon external fuel tanks. This extra fuel also allowed for up to an hour or more loiter time over Japan before they returned to Iwo Jima.

The last combat missions flown by Mustangs in the Second World War were on 14 August 1945. Firstly, 160-plus P-51s from Iwo Jima escorted 145 B-29s that bombed the Osaki Army Arsenal and alternate targets. The Mustangs also attacked airfields in the Nagoya area with a loss of one P-51. Lastly, Far East Air Forces P-51s attacked Japanese shipping in North Korean and Kyushu, claiming several vessels destroyed and damaged with no losses. A final tally found that the three fighter groups equipped with Mustangs based on Iwo Jima had flown some 1,700 sorties between 7 April and 14 August 1945, and had produced four aces. Respectively, the 15th FG, 506th FG and 21st FG got 111, 24, and 71 kills during their VLR escort missions.

The NA-144 programme was initiated by NAA on 12 December 1945 for the production of 100 P-82E Twin Mustang night (all weather) aircraft. These would be powered by 1,930 hp Allison V-1710 engines with water injection and auxiliary stage superchargers.

Mustang operations were not completely over as many were needed for the occupation of Japan that quickly followed VJ Day on 2 September 1945. The 15th FG remained on Iwo Jima until November 1945 and was disestablished on 15 October 1946. The 506th FG remained on the island until December 1945 and was disbanded on 16 December 1946. The 21st FG transferred from Iwo Jima to Saipan, then to Guam before it was inactivated on 10 October 1946.

From 1 January 1945 to 31 August 1945, NAA delivered 5,111 Mustangs – 3,276 P-51Ds and P-51Hs from Inglewood and 1,835 P-51Ds, F-6Ds, P-51Ks, F-6Ks, TP-51Ds – and a single P-51M from Dallas.

Mustang Production 1941-1945

According to an official document entitled Factory Acceptances of all Military Airplanes, by Type of Airplane: January 1940 to August 1945 that was published in 1946 by the Statistical Control Office of the Air Technical Service Command for 1940 to 1945, the production totals for USAAC-cum-USAAF Mustangs is as follows:

Inglewood, California: 

A-36A – 142 in 1942 and 358 in 1943 (500 total) 

XP-51, P-51, P-51A, XP-51B, P-51B, XP-51D, P-51D, XP-51F, XP-51G, P-51H, XP-51J – 138 in 1941, 634 in 1942, 1,533 in 1943, 4,368 in 1944 and 3,276 in 1945 (9,949 total)

Dallas, Texas: 

P-51C, P-51D, TP-51D, P-51K, P-51M – 117 in 1943, 2,540 in 1944 and 1,835 in 1945 (4,492 total) 

F-6D, F-6K – 74 in 1944 and 225 in 1945 (299 total)

Subtotals for both production facilities: 

A-36 – 500 

F-6 – 299 

P-51 – 14,787

Grand total: 15,586 (this total includes the single NA-73X and the 320 NA-73 and the 300 NA-83 Mustang Mark I airplanes built under contracts for the RAF and the 100 P-51D airplanes built for Australia). Thus the final total of Mustangs built is 15,586.