Staff Writer (Updated: 4/5/2016):
The initial requirement of 1952 called for an agile fighter capable of Mach 1.2 speeds with afterburning powerplants. Armament would center around a battery of internal cannons as standard with support for aerial rockets and provision for early-generation American Air-to-Air Missiles (AAMs). As a fleet defense fighter, rate-of-climb became an important quality for intercepting incoming aerial threats - this led to the agreed upon rate-of-climb of 25,000 feet per minute. Submissions were delivered from such prominent American defense industry players as Douglas, Grumman, Lockheed, McDonnell, North American, and Northrop.
Famous American aviation engineer Ed Heinemann designed the F4D "Skyray" for Douglas Aircraft Company and this aircraft first flew in January of 1951 before being adopted by the USN in 1956. It was this general form that was selected for an all-weather guise as the "F4D-2N" to be outfitted with one Westinghouse J40 turbojet engine. The USN saw enough of this proposal to further it into 1953. Douglas engineers largely retained the same form of the Skyray but nonetheless revised it through a thinner, longer fuselage and slimmer, stronger wings. Aerodynamic refinements were applied where possible - a rare opportunity for engineers to right some of the wrongs of their original approach. The design evolved enough to warrant its own designation of "F5D" with the name "Skylancer" eventually following. The USN commissioned for nine test aircraft which was to lead a 51-strong production order of the new fighter pending evaluations.
A prototype F5D achieved first flight on April 21st, 1956 and its design proved sound with good handling characteristics. However, by this time the USN's interest in the Douglas fighter was waning for its attention had fallen on a competing submission from Chance-Vought - the models evolving to become the famous F8U "Crusader" fighter line. This move left the F5D with no requirement to fulfill, leading the USN to terminate its commitment to the F5D in March of 1957. Just four of the expected nine test aircraft were realized before the end. These aircraft were then passed on to NASA for various aeronautical experiments during the 1960s. The last flight of a Skylancer occurred in 1968.
As completed, the F5D design physically mimicked some of what made the earlier F4D Skyray an iconic 1950s-era American fighter. It featured a short, though pointed, nose cone with good downward visibility, triangular wing root-mounted intakes, swept-back wing mainplanes with rounded tips, and a single vertical tail fin. The aircraft exhibited an overall length of 16.4 meters with a wingspan of 10.2 meters and height of 4.5 meters. The undercarriage included three retractable, wheeled legs (two main and one nose). The single engine configuration was nestled within the airframe and exhausted through a large circular port under the tail fin.
While originally intended to carry a Westinghouse J40 turbojet engine, the aircraft was eventually revised to take on the more powerful Pratt & Whitney J57-P-8 turbojet engine (16,000 lbf with afterburner). It was further expected that production-quality aircraft would eventually graduate to use the Pratt & Whitney J57-P-14 engine with future consideration given to mounting the General Electric J79 engine. The PW J57-P-8 fitted offered a maximum speed of 990 mph (Mach 1.48) with a range out to 1,335 miles. Its service ceiling reached 57,500 feet with a rate-of-climb nearing 20,730 feet per minute.
Beyond a standard armament of 4 x 20mm internal cannons there was to be support for up to 72 x 2" (51mm) HVARs as well as provision for the carrying and launching of AIM-9 "Sidewinder" and AIM-7 "Sparrow" AAMs. The F5D would have carried four of the former or two of the latter.