Combi aircraft in commercial aviation are aircraft that can be used to carry either passengers as an airliner, or cargo as a freighter, and may have a partition in the aircraft cabin to allow both uses at the same time in a mixed passenger/freight combination. The name combi comes from the word combination. The concept originated in railroading with the combine car, a passenger car that contains a separate compartment for mail or baggage.

The Boeing 707 is an early American long-range narrow-body airliner, the first jetliner developed and produced by Boeing Commercial Airplanes. Developed from the Boeing 367-80 prototype first flown in 1954, the initial 707-120 first flew on December 20, 1957. Pan Am began regular 707 service on October 26, 1958. With versions produced until 1979, the 707 was a swept wing quadjet with podded engines. Its larger fuselage cross-section allowed six-abreast economy seating, retained in the later 720, 727, 737, and 757 models.