Отменённый проект перехватчика XF-108 Rapier

Canceled interceptor aircraft project

The North American XF 108 Rapier was a proposed long range, high speed interceptor aircraft designed by North American Aviation intended to defend the United States from supersonic Soviet strategic bombers. The aircraft would have cruised at speeds around with an unrefueled combat radius over , and was equipped with radar and missiles offering engagement ranges up to against bomber sized targets. To limit development costs, the program shared engine development with the North American XB 70 Valkyrie strategic bomber program, and used a number of elements of earlier interceptor projects. The program had progressed only as far as the construction of a single wooden mockup when it was cancelled in 1959, due to a shortage of funds and the Soviets' adoption of ballistic missiles as their primary means of nuclear attack. Had it flown, the F 108 would have been the heaviest fighter of its era. Prior to the project's cancellation, U. S. President Dwight D. Eisenhower noted that raising the F 108 interceptor force would have cost the U. S. taxpayer $4 billion (equivalent to $4.0 in 1959 is equivalent to about <calculated amount> in recent years billion today).

During the early 1950s, the USAF proposed a very high performance, long range interceptor. On 20 July 1955, formal development of what became known as the Long Range Interceptor, Experimental (LRI X) was approved, planned as an F 102 Delta Dagger/F 106 Delta Dart replacement. It was to have a two man crew and at least two engines. Of the eight interested companies, contracts for preliminary studies were issued to North American Aviation, Lockheed and Northrop on 11 October 1955, five days after the specification's release. Political and budgetary difficulties led to the cancellation of the program on 9 May 1956.

After considerable confusion, the program was reinstated on 11 April 1957 with North American awarded a contract for two prototypes. The designation F 108 was issued, also known as "Weapon System 202A" (WS 202A). North American's company designation was "NA 257", although it was basically identical to the NA 236. At the time, Air Defense Command anticipated an order for 480 aircraft. The resulting design went through considerable evolution, owing to both its cutting edge technology and continual redefinition of the USAF requirements. Early revisions prominently featured canards, with a span of 19 feet (6 m), and a wing of 53.5° sweep. From September 1958, substantial engineering and design changes were implemented; however, SAC had lost interest in the escort fighter concept. To accompany the B 70 all the way to its target and back, the F 108 in its initial concept would have, at best, marginal range. On 30 December 1958, YF 108A preproduction aircraft on order were reduced from 31 to 20 test aircraft and the first test flight was delayed from February to April 1961.

Even as the XF 108 program was progressing well, there were signs that would ultimately lead to its eventual cancellation. Unconfirmed Soviet bomber threats, the overwhelming trend toward offensive and defensive nuclear missiles in the late 1950s and early 1960s, as well as rising costs, contributed to the termination of the XF 108. The cancellation was announced on 23 September 1959. Despite the extra money and time spent on the Rapier, it was not wholly in vain; the North American A 5 Vigilante supersonic carrier based nuclear strike bomber developed for the U. S. Navy, which was later modified into a carrier based reconnaissance aircraft, retained the fuselage/weapon package and systems design of the Rapier. In many ways the Vigilante could be seen as the successful application of the Rapier design principles in a Mach 2 supersonic design. Hughes Aircraft would continue the development of the advanced fire control system and the GAR 9 missile.#tag:ref|Quote: "The Pentagon did, however, continue development of the ASG 18 fire control system and GAR 9 missile. The final configuration for the rear cockpit in the YF 12A looked similar to that of the F 108 since it incorporated the same displays and controls required for the Hughes AN/ASG 18 fire control system.

The initial F 108 configuration featured a very large "cranked" delta wing. There were fixed ventral stabilizers on the wings, mounted at mid span, and a tall all moving vertical tailfin, supplemented by two ventral stabilizers that extended when the landing gear retracted. Although some earlier versions of the design had separate tailplanes or forward canards, both were abandoned in the final design. The large fuselage and wing had two and five fuel tanks, respectively, giving an estimated combat radius of some Top speed was estimated at , about Mach 3, at 81800 feet (24933 m). The F 108 was intended to carry the Hughes AN/ASG 18 radar, the U. S.'s first pulse Doppler radar set. It was to have look down/shoot down capability, but could track only one target at a time. The radar was paired with an infra red search and tracking (IRST) system on the wing leading edges. The radar was used to guide the Hughes GAR 9 (later redesignated AIM 47) air to air missile, three of which would be carried on a rotary launcher in an internal weapons bay.

As part of WS 202A, a design for a high speed (Mach 3+) aerial target for use in testing the F 108's weapons system was proposed. The Wright Air Development Center requested the designation XQ 11 for the target design; the request was denied due to the early stage of development, and the F 108 program was cancelled before further work was undertaken.