The Boeing 2707 was the supersonic transport project canceled before a prototype entered service.
Boeing developed the 2707 in response to the expected market for supersonic passenger travel. The project evolved from an early variable-sweep-wing concept to a larger fixed-delta-wing design. It was intended to carry passengers at more than twice the speed of sound.
The program faced escalating costs, technical challenges, environmental concerns about sonic booms, and uncertainty about airline demand. The United States government ended its financial support in 1971, and Boeing subsequently terminated the project. No completed production aircraft entered commercial service.
The 2707 is often compared with the Anglo-French Concorde, which did enter passenger service, and with the Soviet Tupolev Tu-144. Boeing’s cancellation meant that the United States never operated a supersonic passenger airliner. The project’s research nevertheless contributed to knowledge about high-speed aerodynamics and aircraft structures.