Douglas F4D Skyray
Overview
The Douglas F4D Skyray (later redesignated F-6 Skyray) is an American carrier-based supersonic fighter/interceptor designed and produced by the Douglas Aircraft Company. It was the last fighter produced by the Douglas Aircraft Company prior to its merger with McDonnell Aircraft to become McDonnell Douglas. Development of the Skyray was started by Douglas during the late 1940s as the D-571-1 design study. It was a delta wing interceptor capable of a high rate of climb as to permit the rapid interception of approaching hostile bombers. Douglas' proposal was selected by Navy officials to fulfill a formal requirement issued in 1948. The decision to adopt the Westinghouse J40 turbojet engine led to considerable difficulties, as this engine would be cancelled prior to entering production, and the aircraft was redesigned to accept the Pratt & Whitney J57 instead. Aerodynamic issues led to a protracted development cycle; considerable design changes were made after the maiden flight of the first production standard Skyray in June 1954. The Skyray was declared ready for fleet introduction in April 1956 and entered service with both the United States Navy (USN) and United States Marine Corps (USMC) shortly thereafter. The Skyray had a relatively brief service life and never saw combat. Despite this, it was the first carrier-launched aircraft to hold the world's absolute speed record, having attained a top speed of 752.943 mph, (1,211.487 km/h). It is widely reported as the first naval fighter to break the speed of sound in level flight rather than in a dive. The Skyray also set a new time-to-altitude record, flying from a standing start to 49,221 feet (15,003 m) in two minutes and 36 seconds, all while flying at a 70° pitch angle. The last Skyrays were withdrawn from service in February 1964, although a handful continued to be flown for experimental purposes by National Advisory Committee for Aeronautics (NACA) up to the end of the decade. The F5D Skylancer was an advanced development of the F4D Skyray that ultimately did not enter service.
