Boeing returned to the commercial aviation industry following World War II with the Stratocruiser, a new long-range airliner (Model 377). Like its military counterpart, the C-97, it was based on the B-29 bomber and was the first Boeing commercial transport since the Stratoliner. It had every speed and technological advancement a bomber could have at the end of the war.
The Boeing 377 Stratocruiser made many promises but proved unreliable and costly to operate. It was designed to be a luxurious long-range passenger airliner based on the C-97 Stratofreighter, a B-29 Superfortress derivative. The company saw the potential for its long-range military transport aircraft for transoceanic flights as it sought to capitalize on ground-based runways rather than the pre-war Boeing 314 Clipper sea routes flown by Pan American World Airways.
William Allen, the president of Boeing at the time, directed the company to build 50 Stratocruiser airliners based on the C-97 despite the fact that the country was enduring a depression in late 1945. Given that no airline had yet placed an order for such a plane, this was a very risky bet. His suspicion was right, though, as Pan Am placed the largest order for an aircraft in aviation history, totaling $24,500,000.
The 377 Stratocruiser had two decks!
The Stratocruiser was much larger than the Douglas DC-6 and featured two pressurized passenger decks with air conditioning. The main deck could accommodate 100 passengers, while the lower deck was a mix of berths and seats.
In April 1949, Pan Am, as the launch customer, began scheduled Stratocruiser flights from San Francisco to Honolulu. By the end of the year, Pan Am, British Overseas Airways Corporation (BOAC), and American Overseas Airlines were all using Boeing 377s on transatlantic routes. By 1955, Stratocruisers were the plane of choice for nearly all global destinations.
What made it special?
The Boeing 377 Stratocruiser was one of the most luxurious and technologically advanced propeller aircraft of its time, but it also had reliability problems and was expensive to operate. The propeller failure on the four 28-cylinder Pratt & Whitney R-4360 Wasp Major radial engines was the main issue with the aircraft. There were numerous in-flight emergencies and hull-loss accidents as a result of the propellor pitch control frequently failing.
The end of the Stratocruiser
On April 29, 1952, while flying over the Amazon on the third leg of a trip between Buenos Aires and New York, the worst of many incidents involving the 377 took place. All 50 passengers and crew were killed when the plane, which had taken off from Rio de Janeiro for Port of Spain in Trinidad and Tobago, unexpectedly disappeared south of the State of Pará. Investigators came to the conclusion that a propeller imbalance caused the second engine to separate from the aircraft.
When the jet era began in the early 1960s, airlines quickly abandoned the costly Stratocruisers in favor of more modern, faster Boeing 707s and Douglas DC-8 jetliners. During its production run, only 56 Boeing 377 Stratocruisers were built.