Wright R-1820 Cyclone
The Wright R-1820 Cyclone is a US radial engine developed by Curtiss-Wright, widely used on aircraft in the 1930s through 1950s. The R-1820 powered many aircraft including early Douglas airliners (the prototype DC-1, the DC-2, the first civil versions of the DC-3), every wartime example of the Boeing B-17 Flying Fortress and Douglas SBD Dauntless bombers, the early versions of the Soviet Polikarpov I-16 fighter (as the M-25), and the Piasecki H-21 helicopter.