The Boeing C-97 Stratofreighter is a military transport aircraft that evolved from the Boeing B-29 Superfortress bomber. Developed in the late 1940s, the C-97 was designed to serve as a cargo and personnel transport for the United States Air Force (USAF), as well as to support aerial refueling operations. It was one of the first true cargo aircraft with a pressurized fuselage, allowing it to fly at higher altitudes and transport personnel and goods more efficiently over long distances.

The C-97’s design was based on the B-29's airframe but with a redesigned fuselage to allow for a large cargo hold and improved load-carrying capacity. The aircraft could be configured for various roles, including troop transport, cargo airlift, and aerial refueling. It became a cornerstone of the early U.S. airlift capabilities during the post-World War II era and was used in a variety of operations during the Korean War and beyond.

Key Specifications (C-97 Stratofreighter)

• Crew: 5 (Pilot, Co-pilot, Flight Engineer, Navigator, and Loadmaster).
• Capacity: 80–100 passengers or up to 20,000 lbs (9,072 kg) of cargo.
• Length: 35.7 m (117 ft 5 in).
• Wingspan: 39.6 m (130 ft 9 in).
• Height: 11.2 m (36 ft 9 in).
• Max Takeoff Weight (MTOW): 70,000 kg (154,000 lb).
• Engines: 4 × Pratt & Whitney R-4360 Wasp Major radial engines, 3,500 hp each.
• Cruise Speed: 300 mph (480 km/h).
• Range: ~3,400 miles (5,472 km).
• Ceiling: 26,000 ft (7,924 m).

Notable Features

• Pressurized Cabin: The C-97 featured a pressurized fuselage, making it one of the first aircraft to offer high-altitude, long-range capability for cargo and personnel transport.
• Aerial Refueling Capability: The C-97 was adapted for aerial refueling operations, providing the U.S. Air Force with an essential tool for extending the range of fighter aircraft and bombers during long-range missions.
• Versatile Cargo Hold: The large cargo hold could be configured for different types of loads, including troops, vehicles, and heavy equipment, and it featured a rear ramp for easier loading and unloading.
• Military and Civilian Use: Though primarily used by the U.S. military, the C-97 also saw service with various civilian operators, including some converted for commercial cargo use after its military service.

Variants

• C-97A: The original military transport version, which retained much of the B-29's design but was modified with a larger fuselage for cargo capacity and added pressurization for the crew and passengers.
• C-97G: The most common variant, featuring upgraded engines and improved systems, making it a more effective transport aircraft during the Korean War and beyond.
• KC-97: A variant modified for aerial refueling duties, capable of carrying and dispensing fuel to other aircraft in flight. This version became one of the primary refueling aircraft for the U.S. Air Force during the 1950s and early 1960s.
• EC-97: A version modified for use as an electronic reconnaissance and communications aircraft during the Cold War.

Operators & Usage

• U.S. Air Force (USAF): The C-97 was primarily used by the USAF for troop transport, cargo airlift, and aerial refueling missions. It played a key role during the Berlin Airlift, the Korean War, and throughout the Cold War era.
• U.S. Army and U.S. Navy: Some C-97s were also used by other branches of the U.S. military, with some adapted for specialized roles.
• Civilian Use: After its military service, many C-97 aircraft were converted for civilian cargo operations by companies like United Airlines and other commercial air freight carriers.
• International Operators: A few C-97s were also operated by foreign military forces during the 1950s and 1960s, though most were eventually phased out as more modern aircraft entered service.