Initially designed by McDonnell Aircraft Corporation as a long-range bomber escort (known as a penetration fighter) for the USAF's Strategic Air Command (SAC), the Voodoo was instead developed as a nuclear-armed fighter-bomber for the USAF's Tactical Air Command (TAC), and as a photo reconnaissance aircraft based on the same airframe. An F-101A set a number of world speed records for jet-powered aircraft, including fastest airspeed, attaining 1,207.6 miles (1,943.4 km) per hour on 12 December 1957.[​1] They operated in the reconnaissance role until 1979.