The Boeing 377 Stratocruiser was a long-range, high-capacity airliner developed in the late 1940s. Based on the military C-97 Stratofreighter, which itself was derived from the B-29 Superfortress, the Stratocruiser was one of the most luxurious airliners of its time. It featured a spacious, pressurized cabin, a distinctive double-deck design with a lower-level lounge, and advanced technology for the era.

First entering service in 1949, the Stratocruiser was primarily used for transatlantic and transpacific flights, offering an unprecedented level of comfort. However, it was expensive to operate and faced strong competition from newer, more efficient aircraft like the Douglas DC-6 and Lockheed Constellation. Despite its relatively short service life, the 377 remains an iconic aircraft in aviation history.

Key Specifications (Boeing 377 Stratocruiser)

• Crew: 4–6 (pilots, flight engineers, and cabin crew).
• Capacity: Typically 50–100 passengers, depending on configuration.
• Length: 33.63 m (110 ft 7 in).
• Wingspan: 43.05 m (141 ft 3 in).
• Height: 11.71 m (38 ft 5 in).
• Max Takeoff Weight (MTOW): 71,640 kg (158,000 lb).
• Engines: 4 × Pratt & Whitney R-4360 Wasp Major radial engines.
• Cruise Speed: ~485 km/h (301 mph).
• Range: ~6,400 km (4,000 mi).
• Ceiling: ~32,000 ft (9,800 m).

Notable Features

• Pressurized cabin, allowing higher-altitude flights for a smoother ride.
• Lower-deck lounge, accessible by a spiral staircase, offering a luxurious space for passengers.
• Double-bubble fuselage design, providing a spacious interior.
• Four powerful radial engines, giving it long-range capability.
• First-class sleeping berths and dining areas, setting new standards for passenger comfort.

Variants

• Boeing 377-10-26 – Standard passenger version used by airlines like Pan Am and BOAC.
• Boeing 377-10-28 – A higher-capacity model with additional seating.
• Boeing 377-10-29 – Used primarily by United Airlines with customized interiors.
• Guppy Conversions – Several Stratocruisers were later modified into Super Guppy and Pregnant Guppy oversized cargo aircraft, used for transporting spacecraft components.

Operators & Usage

• Major operators included Pan American World Airways (Pan Am), British Overseas Airways Corporation (BOAC), American Overseas Airlines, and United Airlines.
• Used extensively for transatlantic and transpacific flights during the late 1940s and 1950s.
• Some aircraft were converted into military C-97 Stratofreighters and later into NASA’s Super Guppy transport aircraft.
• Retired from passenger service in the early 1960s, but its unique design lived on through specialized cargo conversions.