Today in Aviation History: First flight of the North American P-51 Mustang

On October 26, 1940, the North American NA-73X — the first prototype of what would become the iconic P-51 Mustang — took to the skies, marking the start of an aviation legend. The aircraft stood out in performance and design, so much so that in 1944 the Truman Senate War Investigating Committee declared it the most aerodynamically perfect pursuit plane in existence. Originally designed for the British Royal Air Force (RAF), the P-51 gained recognition as the finest all-around piston-engine fighter and was later adopted by the U.S. Army Air Force (USAAF). This amazing marvel was designed and produced by North American Aviation (NAA) under the leadership of James H. Kindelberger. However, the designing and manufacturing process was a roller-coaster ride of its own, worth every high and low.

Ready for Immediate?

As the RAF was expanding in early WWII, there were no U.S. fighter aircraft in production that could meet the British air arm’s standards. The only aircraft that came close was the Curtiss P-40 Tomahawk, however the Curtiss-Wright production line was already running at capacity to satisfy existing orders. Hence, the British Purchasing Commission (headed by Sir Henry Self) approached NAA to build Curtiss P-40 fighters under license for the RAF. But Kindelberger claimed his NAA team could fly a more modern fighter using the same Allison V-1710 engine sooner than they could establish a production line for on an old design from another company. The Commission agreed to the new prospect but remained skeptical of NAA’s expertise in the area as the firm had never designed a pursuit (fighter) aircraft, so Sir Henry suggested NAA obtain Curtiss P-40 data and wind tunnel test results before entirely committing to a detailed design. In order to make their commitment to a new fighter more evident, NAA purchased the P-40 design and data from Curtiss for £56,000.

The Commission was satisfied and, on May 4 1940, the contract was signed: 102 days later on September 9, 1940 construction of the first prototype, NA-73X, was completed. The prototype made its first flight on October 26 that year with test pilot Vance Breese at the controls, the test flight giving successful results and the prototype showcasing good handling characteristics along with satisfactory payload at lower altitudes. As NAA used the same Allison V-1710 as the Curtiss P-40 the aircraft had a limited performance at high altitudes, a power drop being observed at altitudes above 15,000 feet, thus making the prototype unsuitable for high-altitude combat.

Change is Good

Observing the drawbacks caused by engine performance, Ronald Harker from Rolls Royce proposed installing the Merlin 61 engine with a two-stage supercharger for a high-altitude performance. Thereafter, in mid-1943, the Allison engines were replaced during a development project known as the Rolls-Royce Mustang Mk.X. After successful engine modifications, the aircraft went under further testing at Rolls-Royce airfield at Hucknall in England. The test results showed successful improvement in aircraft’s performance at altitudes above 15,000 ft along with a significant range.

Apart from the engine enhancements, the aircraft was also equipped with a cooling system that was aft-positioned to reduce the fuselage drag and generate jet thrust from heating air exiting the radiator. The fuselage was a mathematical marvel, designed using conic sections for smooth and low-drag surfaces, NA-73X being one of the first aircraft to showcase this feature. This design featured three sections and was entirely composed of aluminum, which further added to lighter weight, better aerodynamics and a successful operational period.

World War II & Beyond

The P-51 started its operational career with the RAF as a tactical reconnaissance aircraft and fighter bomber and entered the first squadron as Mustang Mk.I in January 1942. A few months later, on July 27, 16 RAF Mustangs went on their first long-range reconnaissance mission over Germany. This would be the first of many such encounters Germany would have with the aircraft as P-51Bs and P-51Cs, and later the superlative bubble-canopy P-51D variant, acted as escorts during the USAAF’s Eighth Air Force bomb raids. With the quantified superiority and efficiency of the pilots and the plane, the P-51 established dominance over the Luftwaffe’s fighter force.

The RAF also continued the use of Mustangs as fighter bombers, the aircraft being a significant factor in the achievement of Allied air superiority in 1944 in the North African, Mediterranean, Italian and Pacific theatres. As WWII proceeded, Mustang pilots almost destroyed 4,950 enemy aircraft. The Mustang continued to serve with various air forces including the Royal Australian Air Force, the South African Air Force, and the Republic of Korea Air Force.

The Mustang was redesignated as F-51 during the Korean War (1950-1953) and remained in service even as more advanced fighters were introduced. The last Mustang in USAF service retired in January 1957 after serving with the West Virginia ANG’s 167th Fighter Interceptor Squadron. Mustangs also gained popularity among civilians as warbirds and air racing aircraft, privately owned Mustangs becoming so popular that in 2011 the FAA registered about 204 examples.

Today in Aviation History is a series highlighting the achievements, innovations, and milestones that have shaped the skies. All the previous anniversaries are available HERE

Haritima Maurya

"Haritima Maurya, pen name, ""Another Stardust,"" has been passionate about writing since her school days and later began sharing her work online in 2019. She was drawn to writing because of her love for reading, being starstruck by the art of expression and how someone can make you see and feel things exclusive to their experience. She wanted to be able to do that herself and share her mind with world cause she believes while we co exist in this beautiful world least we can do is share our little worlds within.

As a commercial pilot, Haritima balances her passion for aviation with her love for storytelling. She believes that, much like flying, writing offers a perspective beyond the ordinary, offering a bridge between individual experiences and collective understanding.

Through her work, ""Another Stardust"" aims to capture the nuances of life, giving voice to moments that resonate universally. "

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