The Douglas DC-3 is a propeller-driven airliner which had a lasting effect on the airline industry in the 1930s/1940s and World War II. It was developed as a larger, improved 14-bed sleeper version of the Douglas DC-2. It is a low-wing metal monoplane with conventional landing gear, powered by two radial piston engines of 1,000–1,200 hp (750–890 kW). (Although most DC-3s flying today use Pratt & Whitney R-1830 Twin Wasp engines, many DC-3s built for civil service originally had the Wright R-1820 Cyclone.) The DC-3 has a cruise speed of 207 mph (333 km/h), a capacity of 21 to 32 passengers or 6,000 lbs (2,700 kg) of cargo, and a range of 1,500 mi (2,400 km), and can operate from short runways.