Pratt & Whitney Double Wasp

The Double Wasp

America’s first 18-cylinder radial engine, the Double Wasp set a new standard for piston engine performance. When it was introduced in 1939, the first models yielded 2,000 horsepower from the combined 2,800 cubic inches — a power level unmatched by any air-cooled engine and better than most liquid cooled models.

The Double Wasp made its fame as the powerplant for some of the most powerful fighters of the Second World War — the F6F Hellcat and F4U Corsair in the U.S. Navy and the ground-pounding P-47 Thunderbolt.


The Double Wasp’s size, a whopping 2,350 pounds, discouraged its use in multi-engine aircraft like heavy bombers, although it was employed on airframes such as the B-26 and A-26. It is often confused with its immediate predecessor, the Twin Wasp (R-1830) that was famous in the DC-2 and DC-3.

The Double Wasp also saw service in twin-engine applications like the P-61 Black Widow night attack fighter and the C-46 Commando transport. Notable in among the late Second World War and immediate postwar period were the F7F and F8F fighters.