![xf 108 xf 108](https://www.alexstoll.com/AircraftOfTheMonth/F-108.jpg)
The resulting design went through considerable evolution, owing to both its cutting-edge technology and continual redefinition of the USAF requirements. At the time, Air Defense Command anticipated an order for 480 aircraft. North American's company designation was "NA-257", although it was basically identical to the NA-236. The designation F-108 was issued, also known as "Weapon System 202A". After considerable confusion, the program was reinstated on 11 April 1957 with North American awarded a contract for two prototypes. Political and budgetary difficulties led to the cancellation of the program on 9 May 1956. The NA-236 shared some similarities with the XF-108, although the most obvious differences were the additions of two finlets at the midspan of the horizontal stabilizers, and canards. Of the paper designs, the North American proposal, dubbed "NA-236", seemed the most promising. 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. A further consideration was that an integrated fire-control system would be fitted, allowing interception of a bomber at 60 nmi (110 km) and three targets to be destroyed during a single mission. It was to have a two-man crew and at least two engines.
![xf 108 xf 108](https://modelingmadness.com/scott/korean/xf108bt.jpg)
The specification was laid down on 6 October 1955, calling for an interceptor that could fly at 60,000 ft (18,000 m) at a speed of Mach 1.7 (1,122 mph (1,806 km/h), with a range of 1,000 miles (1,600 km). On 20 July 1955, formal development of what became known as the Long-Range Interceptor, Experimental (LRI-X) was approved, planned as a F-102 Delta Dagger/ F-106 Delta Dart replacement. Following the program's termination, the fire-control system, incorporating the Hughes GAR-9 missile, was adapted for the Lockheed YF-12, which was itself canceled.ĭuring the early 1950s, the USAF proposed a very high-performance, long-range interceptor. Had it flown, the F-108 would have been the heaviest fighter of its era.
![xf 108 xf 108](https://64.media.tumblr.com/b77029c3aae2b4001ee0b0b95e895e14/1facddf5683792cf-34/s540x810/aa9ca6816c5bd1536df247e027537b962dc527ca.jpg)
The program had progressed only as far as the construction of a single wooden mock-up when it was cancelled in 1959, due to a shortage of funds and the Soviet's adoption of ballistic missiles as their primary means of nuclear attack. 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 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 bombers. Note: Top aircraft's weapons bay opening. Artist's impression of two F-108s attached to Elmendorf AFB, Alaska.