The P51 Mustang was a single engine fighter airplane first produced for the British Royal Navy. It was created to be escort planes for heavy bombing campaigns, but its use expanded beyond that initial intention. Nicknamed the "little helper" by bomber pilots, the P51 became the most successful fighter plane of its day.
The Mustang most often produced had a 37 foot (11.28 meter) wingspan and was just over 32 feet (9.75 meters) long. It stood 13 and a half feet (4.11 meters) tall. The Packard Merlin engine became the standard after it proved the most suited for a fighter of this size. The P51 could carry 2,000 lbs (907 kg) and had a range of about 950 miles (1,529 km). It was armed with six .50 caliber machine guns mounted on the wings for a total of 1,880 rounds.
In April of 1940, The British Royal Air Force (RAF) was preparing their forces for war to break out into a full-scale event. They commissioned North American Aviation to build P40s for the Royal Air Force. The design team at North American were reluctant to build more P40s since they were becoming an outdated aircraft. they offered to Use the same engine, but design a new craft around it. The RAF agreed, as long as the craft, being called the NA73, could be produced in under 120 days.
The United States Army approved the export of the NA73 as long as they could have two planes for their own evaluation. It was the US Army that renamed the plane the XP51. They design team at North American got together and produced the prototype in only 117 days. The first flight was 26 October 1940 where it blew away previous fighter planes, topping out at 382 mp/h (614 kp/h), a full 25 mp/h (40 kp/h) over the top speed of the P40.
The key to the speed was in the wing design. Other aircraft of the time had wings that reached maximum thickness right around the front or within the first 25% of the wing. The new wing design of the P51 called "laminar flow airfoil" had the maximum thickness beginning a bit more than halfway into the wing. This design allowed for air to flow easier over the wing and therefore reduce drag. As drag was reduced, speed was increased.
The plane originally had an Allison engine, like the former P40. It was a good engine, but lacked the altitude capabilities that were necessary in the best fighters. The RAF got the idea to use a Rolls-Royce Merlin Engine instead. It was successful at increasing altitude and the results were passed on to the US Air Force. The US Air Force had been doing similar tests using Packard Merlin engines and achieved similar results. On top of improving altitude performance in the P51, the air speed was also increased to a whopping 441 mp/h (710 kp/h).
Another major design feature introduced in subsequent P51 models was the bubble canopy. This clear canopy went completely around the pilot in a bubble, allowing for a full field of view. Previous aircraft models did not allow the pilot to see behind, making the aircraft susceptible to enemy fire approaching from the rear.
There were a total of over 15,000 P51 aircraft built between 1940-1945. They were responsible for the destruction of 4,950 enemy aircraft, making them the most destructive plane in US fighter history. About 280 P51s are still airworthy, kept alive by warbird enthusiasts around the globe.