History
Design and Development
Douglas F5D-1 Skylancer was followed by the development of F4D-2N, an all-weather version of the F4D-1 Skyray, in 1953. It was decided to aerodynamically refine the design to exploit an extra thrust of the Pratt & Whitney J57 fitted to the Skyray instead of the planned Westinghouse J40. Two prototypes were ordered under the initial designation F4D-2N. They redesignated the F5D-1 Skylancer, as the new design became more different from the F4D-1.
The F5D-1 retained the delta wing planform and overall wingspan and wing area of the F4D-1. However, the wings were much thinner, and the fuselage was 8 feet longer. The wing was built with thicker reinforced skinning to correct problems encountered with dents, dimples, and depressions, which could happen during high-speed maneuvering with the F4D-1 Skyray. The internal fuel capacity was increased from 640 US gallons of the F4D-1 to 1,383 US gallons. The fuselage of the F5D-1 was slimmed down in the region of the wing roots to improve the transonic flight characteristics. The air intakes were redesigned, a taller fin and rudder were fitted, and the landing gear track was widened. The leading edge slat arrangement, rear control surfaces, and inboard trailing edge trimmers were all redesigned. The prototype F5D-1 retained the same J57-P-8 engine as the F4D-1, but the afterburner cooling intakes were enlarged and moved forward. The armament consisted of retained four 20-mm cannons, four Sidewinders, and new unguided rockets. Both guns and unguided rockets were to be mounted in armament bay doors beneath the F5D-1’s fuselage.
The F5D-1 Skylancer would have an advanced electronics fit with an APQ-64 radar in place of the F4D-1’s APQ-50 radar, as Douglas intended to combine it with a new weapon in development, the Sparrow II or the AIM-7B Sparrow. It was an evolution of the earlier (AIM-7A) Sparrow I beam-riding missile, and it would have an active radar seeker that enabled a fire-and-forget capability. However, with the Sparrow’s technical limitations and insufficient performance from the test firings, Douglas dropped out of the Sparrow II program in 1956.
Flight Testing
With the F5D-1 Skylancer design evolving enough to interest the US Navy, it ordered nine test aircraft and fifty-one production aircraft. The production variants intended to have the more powerful J57-P-14 engine, which provided some 16,900lbf thrust with an afterburner. The later production aircraft would be planned to have the General Electric J79, which would have provided even more power to make the Skylancer capable of Mach 2 flight.
The first F5D-1 (193208) took off from Edwards Air Force Base and made its first flight on April 21, 1956. It managed to exceed the speed of sound during the flight and could attain a maximum speed of nearly 1,000 mph at altitude. It also had excellent handling characteristics.
Consequences of Politics
Shortly after two prototypes and two production aircraft had been constructed, the Navy canceled its order for the F5D-1 Skylancer. Douglas abandoning the Sparrow II program didn’t help it that much. The Navy had chosen the Vought F-8 Crusader to be its primary supersonic fighter in service, which stated that the Navy did not need to have another fighter that shared very similar performance characteristics.
The F5D-1 Skylancer not only served as a backup but also as a backup to a backup. The Navy had ordered the Vought F-8 Crusader in 1953 and improved the Grumman F11F-1F Super Tiger in 1955, so the F11F-1F was a backup to the F-8 Crusader in case of failure while the F5D-1 was a backup to the F11F-1F as well as to the F-8. The F-8 Crusader had been proved highly successful, so neither F11F-1F nor F5D-1 had entered production and Navy service. Another potential reason speculated by historians that the decision to select the F-8 over the F5D-1 was to curb Douglas’s de facto monopoly on military aircraft contracts for the Navy, as the company was already producing the A3D Skywarrior, A4D Skyhawk, and the AD Skyraider.
However, this was not the end of the F5D-1 Skylancer. Four aircraft continued to fly in various military test programs in the late 1950s and early 1960s. Two F5Ds were grounded in 1961 for spare parts, and the other two F5Ds became NASA test aircraft in research programs during the 1960s. Both NASA F5D-1s were retired in 1970, and these are the only two surviving aircraft that ended up as museum aircraft today.
