Boeing 377 Stratocruiser

The Boeing 377, also called the 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.

Released in the late 1940s, the aircraft was powered by four piston engines, driving tractor propellers. The aircraft was able to cruise at about 32,000 feet. It also had a pressurized cabin, which was a relatively new feature to transport aircraft at the time, and two decks. Airlines were able to make transoceanic flights easier and faster with the new aircraft, which enabled easier international travel to places such as Hawaii.

Nevertheless, the Stratocruisers did not have great reliability (chiefly due to chronic problems with the extremely complex[citation needed] 28-cylinder R-4360 engines and the associated propellers) and only 56 were built for airlines.

Design and development

Like the C-97, the 377 was developed towards the end of World War II by adapting an enlarged upper fuselage onto the lower fuselage and wings, which were essentially the same as those of the B-50 Superfortress, the high-performance evolution of the B-29 Superfortress bomber. The 377 was larger and longer-ranged than the Lockheed Constellation and Douglas DC-6, with nonstop transatlantic range eastbound. Production ended in 1950.

The "inverted-figure-8" double-deck fuselage design provided 6,600 ft³ (187 m³) of interior space where the lower deck had a smaller diameter than the upper deck. It offered seating for over 100 passengers, or sleeping berths for up to 28 berthed and five seated passengers. It first flew on July 8, 1947. It had the speed and range to span ocean routes, enabling flying from New York to Hawaii in less than 24 hours.[3] Pressurization (previously introduced on the Boeing Stratoliner and also designed into the B-29) allowed sea-level cabin pressure at 15,500 ft (4,700 m) altitude. At 25,000 ft (7,600 m), passengers enjoyed a "cabin altitude" of only 5,500 ft (1,700 m).

Operational history

Despite a service record remembered for one or two early disasters arising from a propeller design fitted to the Stratocruiser in its earlier years, Boeing's remarkable airliner was one of the most capable of post-war propeller-driven transports, and certainly among the most luxurious. Only 55 were built as airliners, joined eventually by the reconditioned prototype to make a total of 56. Another 60 of this general design, with significant engineering differences, were built as C-97 military transports, but the majority were built as KC-97 tankers.

The Stratocruiser flew premier services to Hawaii, across both oceans, and elsewhere in the world. It was one of the few airliners with a double-decker seating arrangement (another was the French Breguet Deux-Ponts) until the 747, though some airlines did have lower-level lounges on their L-1011 Tristar aircraft. The upper deck was for 55-100 passenger seats or 28 sleeper berths, while the lower deck had a lounge and bar. Passengers could walk down and get a drink on the long flights, once the plane levelled off at cruising altitude.[citation needed]

In the early 1960s these planes were starting to become superseded by jets such as the de Havilland Comet, Boeing 707 and Douglas DC-8. A few survived to be sold to smaller airlines, used as freighters or converted into a specialised freighter called a Guppy. As the airlines began to upgrade so did the militaries that were using them. The Boeing 377 was primarily used in only two militaries, the US and Israeli, both of which began buying jet engine aircraft and replacing their 377s.