Pratt & Whitney R-1690 Hornet

The Pratt & Whitney R-1690 Hornet was a widely used American aircraft engine, a single-row, nine-cylinder, air-cooled radial that displaced 1,690 cubic inches, about 27.7 litres. Pratt & Whitney built 2,944 of them from 1926 through 1942, and it first flew in 1927. Variants raised the power from 525 horsepower in the R-1690-3 to 1,050 horsepower in the R-1690-S1C3G. It was built under licence in Italy as the Fiat A.59, and in Germany the BMW 132 was a developed version of this engine, while an enlarged version, the R-1860 Hornet B, was produced from 1929. An R-1690 is on display at the New England Air Museum at Bradley International Airport, Windsor Locks, Connecticut.