The Boeing KC-97 Stratofreighter was a strategic tanker derived from the C-97 transport and B-29 bomber. Developed by the Boeing Airplane Company, the aircraft's design incorporated the wings, tail, and landing gear of the B-29, while introducing a pressurized "double-bubble" fuselage. This unique structural design allowed the aircraft to function as a multi-role platform, capable of serving as a tanker, cargo carrier, and troop transport. In its transport configuration, the C-97 could carry 96 fully equipped troops or 69 litter patients; however, the installation of refueling equipment in the KC-97 reduced these capacities to 65 troops and 49 litter patients, respectively.
Production of the KC-97 took place between 1951 and 1956. While total production figures for the C/KC-97 family are cited between 888 and 890 airframes, documented purpose-built tanker variants (KC-97E, F, and G) totaled at least 811, with a small number of additional conversions. The KC-97 is most notable for being the first USAF tanker equipped with a refueling boom, a system refined from the KB-29 that replaced the previous hose-and-drogue method. The KC-97G variant further enhanced this versatility by allowing the aircraft to operate as both a tanker and a cargo transport without requiring modification.
Powering the aircraft were four Pratt & Whitney R-4360 Wasp Major air-cooled radial piston engines, producing between 3,500 and 3,800 hp each. To address the speed disparity between piston tankers and early jet receivers, the KC-97L variant was introduced. These aircraft were equipped with two underwing General Electric J47 turbojet pods, adapted from KB-50 tankers, to boost speed for short durations when refueling aircraft such as the F-84, F-100, and F-101.
Operating from 1950 through 1978, the KC-97 served primarily with the Strategic Air Command (SAC), Tactical Air Command (TAC), and the Military Air Transport Service (MATS). In later years, the aircraft became a staple of the Air National Guard (ANG) and Air Force Reserve. A notable deployment was Operation Creek Party, beginning in 1967, where units like the 160th Air Refueling Group of the Ohio ANG supported NATO and USAF forces in Europe. The final KC-97L aircraft were retired from the Texas and Utah ANG in 1978, replaced by the C-130 Hercules and KC-135 Stratotanker. Today, examples are preserved at the Smithsonian National Air and Space Museum, Pima Air & Space Museum, and Castle Air Museum.