Past Talks : September 2022

“Development of the P-51 Mustang” by Rod Dean (Sqn Ldr(Ret’d)


Rod thought the Mustang was probably a better aircraft than the Spitfire, because it would escort bombers all the way to distant targets. It had the same engine as the Spitfire, but was faster, carried more ammunition and had a better range. Rod put this down to good design and exacting production techniques. All were built to very high tolerances and all parts were interchangeable

The Mustang design originated in a proposal from the British Purchasing Commission to North American to build Curtiss P40 Tomahawks for Britain. Instead, North American suggested that it could design a better aircraft. The Ministry of Aircraft Production placed an order for 320 aircraft in March 1940 and 102 days later in September 1940, the finished aircraft was rolled out of the factory. Early Mustangs were fitted with Allison V-1710 engines, which suffered poor performance above 15,000ft. The very first RAF Mustang 1, AG346, entered service on 23 April 1941 and lasted until 24 August 1944.

Lend-Lease Mustangs were designated Mustang IA. fitted with four 20mm canon instead of machine guns. An uprated Allison-engined version equipped with drop tanks was called the Mustang II by the RAF and P51A by the US. To overcome the shortcomings of the Allison engine, Rolls Royce suggested installing a Merlin 61 engine with a two-speed, two-stage supercharger. This variant was flight tested in October 1942 and became the RAF Mustang III (US P51B and P51C). It adopted the British-designed sliding ‘Malcolm’ hood, which improved visibility. The US car company Packard was selected to build the Merlin under licence for all Mustangs.

The RAF Mustang IV (US P51D) introduced a full bubble canopy and an additional 85-gallon fuel tank behind the pilot. More P51D models, recognisable for having a three-blade propeller, were made than any other mark. A tandem two-seat version of the P51D was developed and many two seat versions are still operating today.

Thank you, Rod Dean, for another very interesting, well-illustrated, talk.