P-51D Mustang

Built for the British, in a hurry

In 1940 Britain was desperate for fighters and asked North American Aviation, a company that had never built one, to make Curtiss P-40s under licence. North American’s president, “Dutch” Kindelberger, said his company could design something better, with the same Allison engine, in less time than it would take to set up a P-40 line. [1] The British agreed. A team under engineer Edgar Schmued drew a clean, mass-producible fighter with two new ideas: a laminar-flow wing, developed with NACA for low drag at high speed, and a radiator mounted behind the pilot whose ducting turned waste heat into a little extra thrust. The prototype was rolled out about 100 days after the order and first flew in October 1940. [1] [2] The RAF named it the Mustang. [2]

A Merlin transforms it

The first Mustangs were fast and handled well low down, but their single-stage Allison engine ran out of breath above about 15,000 ft, where the air war over Europe was being fought. In 1942 a Rolls-Royce test pilot, Ronald Harker, suggested fitting the two-stage supercharged Merlin from the SpitfireSpitfire LF Mk IX AircraftThe elliptical-winged British fighter; the Merlin 66-powered Mark IX answered the Fw 190. IX. [1] The result was about 50 mph faster, and as the US-built Packard Merlin it became the P-51B. With an extra fuel tank behind the pilot and drop tanks under the wings, it could escort bombersFighter escort GlossaryJoint terms: An offensive counterair operation providing dedicated protection sorties by air-to-air capable fighters in support of other offensive air and air support missions over enemy territory, or in a defensive counterair role… from England to Germany and back. [1] [2] The P-51D followed with a cut-down rear fuselage, a bubble canopy that gave the pilot an all-round view, and six .50 calibre guns instead of four. More D models were built, 8,302, than all other versions combined. [2]

Over Berlin

In 1943 American heavy bombers were suffering terrible losses over Germany, because no Allied fighter could stay with them all the way to the target. The Mustang could. [1] [2] At the start of 1944 Major General James Doolittle, the new Eighth Air Force commander, freed his fighters from flying close escort and sent them out ahead to hunt the Luftwaffe wherever it could be found; bomber crews complained, but by June the Allies had air supremacy. By the end of 1944, 14 of the Eighth’s 15 fighter groups flew Mustangs. [1] Hermann Göring, head of the Luftwaffe, was quoted as saying: “When I saw Mustangs over Berlin, I knew the jig was up.” [1]

By May 1945, P-51 groups in Europe had claimed about 4,950 aircraft shot down, roughly half of all US claims in the theatre and more than any other Allied fighter, and 4,131 destroyed on the ground, for about 2,520 losses. The top Mustang ace, George Preddy, scored 23 of his 26.83 victories in the P-51 before he was killed by friendly fire on Christmas Day 1944. [1] Mustangs even caught Germany’s new jets: Chuck Yeager of the 357th Fighter Group shot down an Me 262 on its landing approach, and on 7 October 1944 Urban Drew of the 361st downed two as they took off. [1] Among the units flying them were the Tuskegee Airmen of the 332nd Fighter Group in Italy. [1]

The Mustang had one weakness. Its liquid-cooled engine depended on a radiator and coolant lines, and a single bullet through either could bring it down, which made strafing far more dangerous for it than for the air-cooled P-47P-47D Thunderbolt AircraftThe heaviest single-engined fighter of the war: eight .50 calibre guns, a turbosupercharged radial, and a fearsome fighter-bomber.. [1] [2]

Iwo Jima to Korea

From March 1945 Mustangs flew from Iwo Jima to escort B-29s over Japan: round trips of 1,500 miles, mostly over water with little navigation equipment, lasting seven or eight hours. [1] After the war the newly independent US Air Force kept the Mustang, renamed the F-51 in 1948, and sent it back into combat in Korea, where its long range let it reach targets that early jets based in Japan could not. It flew ground attack there with the US, South African, South Korean and Australian air forces, and its cooling system again made it vulnerable to ground fire. [1] [2] The US Air Force retired its last P-51s in 1957, and the Dominican Air Force flew them until 1984. [1] [2]