R2800

The R-2800, commonly known as the Double Wasp, is an 18-cylinder, air-cooled radial piston aircraft engine developed by Pratt & Whitney. Introduced in the late 1930s, it became one of the most widely used US military engines of World War II, powering a range of fighters and bombers and contributing significantly to Allied air capabilities.

Design and development aspects are characteristic of late-era radial powerplants. The engine uses two rows of nine cylinders arranged around a single crankcase, with air cooling and options for supercharging to maintain performance at higher altitudes. Across its many variants, the R-2800 was refined to improve takeoff power, high-altitude performance, and reliability, with adjustments to compression ratios, supercharger gear, and cooling for different aircraft and mission profiles.

Applications and impact were substantial. The R-2800 powered several iconic aircraft, including fighters and bombers such as the F6F Hellcat, F4U Corsair, and P-47 Thunderbolt, among others. Its combination of robust construction, high power-to-weight for its era, and versatility underpins its reputation as a workhorse of the war effort. The engine’s widespread deployment helped sustain Allied air superiority through much of the conflict.

Legacy and service history extend beyond World War II. The R-2800 remained in production and use for several years, with various export and military follow-ons, and it influenced subsequent large radial designs. It is regarded as a benchmark for reliability and performance in mid-20th-century piston-engine aviation.