The Boeing 377 Stratocruiser was a large long-range airliner built after World War II. It was developed from the C-97 Stratofreighter, a military derivative of the B-29 Superfortress used for troop transport. The Stratocruiser's first flight was on July 8, 1947.
Put into production in the late 1940s, the aircraft had four radial engines mounted in a tractor configuration. It had two decks and a pressurized cabin, a relatively new feature to transport aircraft.The Stratocruiser was more expensive to buy and operate than the competing Douglas DC-6 and Lockheed Constellation. It had mediocre reliability, chiefly due to chronic problems with the 28-cylinder Pratt & Whitney Wasp Major radial engines and their four-blade propellers. Only 55 Stratocruisers were built for airlines.