June 2001 (Be-1200/Be-2500) Home August 2001 (Northrop F-5)
This Month in Aviation History

Aircraft of the Month for July 2001

North American (X)F-108 Rapier

by Alex Stoll


he USAF started the Long-Range Interceptor, Experimental (LRIX) program on 6 October 1955. North American received a letter contract for two prototypes of a long-range high-performance interceptor to be designated F-108A on 6 June 1957. They began designing the NA-257, a Mach 3-capable long-range interceptor meant to destroy Soviet bombers over the poles before they could fly over American terrotory. It was also meant to escort the North American B-70 Valkyrie Mach 3 strategic bomber. Service entry of the first of an anticipated total of at least 480 F-108s was expected in 1963. The F-108A design featured large delta wings and two afterburning General Electric J93-GE-3AR turbojets, the same engines that powered the XB-70. The F-108 was designed for a 1640-kilometer combat radius and a maximum speed of 3190 km/h at 23,340 meters. The pilot and radar operator sat in individual ejector capsules in the forward cockpit.
An extremely sophisticated avionics system directed by the Hughes AN/ASG-18 search and tracking radar was selected for the F-108. The ASG-18 was to have a range of over 160 kilometers (100 miles). Three advanced Hughes GAR-9 Falcon missiles were to be carried in the internal weapons bay. A Lockheed storable liquid-propellant rocket motor capable of driving the missile to hypersonic speeds of up to Mach 6 and achieving ranges of up to 185 kilometers (115 miles) powered the GAR-9. Semiactive radar homing was used for midcourse guidance with passive infrared homing used for terminal guidance.
The original configuration was with canards and three vertical tails: one in the middle and two halfway down the wing trailing edges for hih speed stability. This was changed, though - the canards and upper portions of the ourboard vertical tails were removed, and the wing was changed to double-delta. In January 1959, a mockup was inspected. The first flight was planned for March 1961. On May 15, 1959, the name "Rapier" was assigned. By mid-1959, the government was not sure it wanted to spend the amount of money required to finish the F-108 program. Additionally, the Soviet Union's ICBMs, which the F-108 would be useless against, were becoming more of a threat that its manned bombers. The USAF also believed that ICMBs could do the job of the B-70/F-108 team more effectively and at a much lower cost. As a result, the F-108 program was cancelled on 23 September 1959, before prototypes could be built, and the XB-70 program was halted. On 3 December 1959, the XB-70 program was cut back to one prototype.

However, technology initially destined for the F-108 found its way into the F-12 interceptor program: the YF-12As used the Hughes AN/ASG-18 radar and the GAR-9 Falcon missile, redesignated AIM-47A in 1962. Although the F-12 program was also cancelled, some of the technology trickled into the F-14 program and the 160-km (100-mi) range AIM-54 Pheonix missile.

An three-view of an early version of the XF-108

Estimated North American (X)F-108 "Rapier" Secifications
TypeHigh-speed high-altitude interceptor
Accomodationpilot and radar operator in tandem
PowerplantTwo General Electric XJ93-GE-3AR turbojets, 92.9 kN (20,900 lb) thrust dry, 133.4 kN (30,000 lb) thrust with afterburning
ArmamentFour 20mm cannons, 108 70mm (2.75 in) rockets and up to 1800 kg (4000 lbs) of bombs; three Hughes GAR-9 Falcon missiles in an internal weapons bay
Max speed3190 km/h (1720 kts/1980 mph) at 23,340 m (76,550 feet)
Service ceiling24,425 m (80,100 ft)
Combat ceiling23,340 m (76,550 feet)
Time to climb to 15,250 m (50,000 ft)5.4 minutes
Initial rate of climb5,490 m (18,000 ft) per minute
Combat radius1640 km (886 nm/1020 mi) with three missiles
Ferry range4610 km (2488 nm/2860 mi)
Empty23,112 kg (50,907 lb)
Combat34,558 kg (50,907 lb)
MTOW46,559 kg (102,533 lb)
Wingspan17.51 m (57 ft 5 in)
Length27.19 m (89 ft 2 in)
Height6.73m (22 ft 1 in)
Wing area576.6 m² (1865 sq ft)

This Month in Aviation History
(Bold indicates anniversaries of multiples of five)
2 July 1970 - First flight of two-seat Viggen prototype
2 July 1959 - First flight of Kaman K-20 (H-2)
4 July 1986 - First flight of Rafale A
4 July 1993 - First flight of the T-3
5 July 1969 - First flight of J-8 prototype
6 July 1972 - First flight of the MFI-17 Supporter
7 July 1973 - First flight of TF-15 (later F-15B)
7 July 1962 - First flight of Lockheed XV-4A Hummingbird
8 July 1948 - First flight of Il-28 prototype
8 July 1975 - First flight of the Shorts 330 production prototype
7 July 1990 - First high-speed taxi tests of YF-23
11 July 1969 - First flight of the MFI-15
12 July 1980 - First flight of the KC-10
13 July 1986 - First flight of the PZL-130 Turbo Orlik (with a PT6)
14 July 1955 - First flight of XP6M-1 prototype
15 July 1937 - First flight of Ha 138 (BV 138) prototype
16 July 1965 - First flight of the first YOV-10A
16 July 1998 - First flight of the T-6A Texan II
17 July 1939 - First flight of the Beaufighter
17 July 1978 - First flight of the Soko Super Galeb prototype
17 July 1989 - First flight of B-2
20 July 1951 - First flight of P.1067 Hunter prototype
20 July 1958 - First flight of a P.531 prototype
20 July 1971 - First flight of the first Mitsubishi XT-2
22 July 1956 - First flight of production Javelin
23 July 1971 - First flight of Nomad N2 prototype
24 July 1956 - First flight of Etendard IV
25 July 1996 - Nimrod 2000 (MRA4) selected to replace Nimrod
26 July 1940 - First flight of a Merlin-powered Beaufighter
26 July 1957 - First flight of BR.1001 Taon
27 July 1972 - First flight of the first development F-15
27 July 1983 - First flight of EMB-120
29 July 1954 - First flight of the MS-760-01
29 July 1981 - First flight of XT-4 prototype
30 July 1954 - First flight of YF9F-9 (F-11 prototype)
30 July 1959 - First flight of N-156
30 July 1976 - First flight of Kiran Mk II
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