The Convair C-131 Samaritan is an American twin-engined military transport aircraft derived from the Convair CV-340 airliner. It is essentially identical to the civilian version, with the main modification being a large side cargo door. The C-131 first flew in October 1951. Initial deliveries to the US Navy began in 1952 (as the R4Y-1), followed by the US Air Force in 1954. With the 1962 redesignation of USN and USMC aircraft, the Samaritan became known as the C-131F, VC-131F, and C-131G.

The United States Air Force (USAF) utilised the Samaritan for medical evacuation and VIP transport. In 1959, a C-131 became the first aircraft used as a reduced-gravity aircraft—or ‘vomit comet’—for astronaut training during Project Mercury. Additionally, in mid-1963, a Samaritan served as the first flying gunship testbed. The Samaritan remained in active service well into the 1980s.

A typical flight crew consisted of four: two pilots, a navigator, and a flight engineer or loadmaster. The aircraft could accommodate up to 44 passengers or carry a payload of 8,069 kg (17,775 lbs). Powered by two wing-mounted Pratt & Whitney R-2800-99 “Double Wasp” 18-cylinder air-cooled radial engines.