A US bomber killer – The Hughes AIM-26 Super Falcon

by Chris Chant on 24/06/2013

Introduced into operational service in 1961 to provide the Convair F-106A Delta Dart of the US Air Force’s Air Defense Command with a very high kill probability against Soviet strategic bombers in head-on engagements before the attacking bombers had been able to penetrate deep into North American airspace, the Hughes AIM-26A Super Falcon was designed on the basis of a semi-active radar homing system as the IR homing systems of the period were inadequate for collision-course engagements.

The original development from 1956 had been based on the concept of parallel development of GAR-5 and GAR-6 versions with semi-active radar and heat-seeking homing, based on the conventional GAR-1 and GAR-2 weapons. The programme was then cancelled, but was revived in 1959.

However, the comparative inaccuracy of semi-active radar homing dictated the use of a particularly powerful warhead to ensure that the target bomber was within the lethal radius of the detonating warhead, and the Super Falcon was therefore designed on the basis of a body with a maximum diameter of 11 in (0.28 m) in the mid-body section but tapered fore and aft of this section, whereas the body of the Falcon was of a constant diameter of 6.4 in (0.163 m).

Nuclear warhead
While this greater body volume allowed the incorporation of a larger rocket motor to ensure that there was not too great a degradation of performance despite the new missile’s greater size and weight, it was really designed to facilitate the installation of a nuclear warhead. This was felt to be the only way to ensure the destruction of a bomber target given the lack of precise terminal accuracy provided by the semi-active radar guidance. The selected W54 warhead was a close relative of the W25 1.5-kiloton type used in the Douglas AIR-2 Genie air-to-air rocket, but had a yield of only 0.25 kilotons and was therefore more akin to the Mk 54 warhead of the M388 ‘Davy Crockett’ recoilless rifle weapon and Special Atomic Demolition Munition, and was detonated by a quartet of active radar proximity fuses.

The new weapon was brought to operational status via about 100 examples of the XGAR-11 (from 1962 XAIM-26) prototype missile with a length of 7 ft 0 in (6.40 m) and a weight of 200 lb (90.7 kg) for a range of 8,800 yards (8045 m) at a maximum speed of Mach 2. These development missiles paved the way for the GAR-11 Super Falcon (from 1962 AIM-26A Super Falcon with length increased marginally to 7 ft 0.25 in (2.14 m) and weight to 203 lb (92.1 kg). Production totalled 1,900 missiles that were replaced after a comparatively short service life by the next variant. Some 300 of the nuclear warheads for AIM-26A missiles were then rebuilt to the W72 standard with a yield of some 600 kilotons for use on a version of the AGM-62 Walleye guided glide bomb.

Introduced as the GAR-11A Super Falcon, the AIM-26B Super Falcon was the derivative of the GAR-11 (AIM-26A) with a conventional warhead to avoid the perceived problems of detonating large numbers of nuclear weapons over the USA. This missile was slightly shorter than its predecessor but somewhat heavier, and production totalled 2,000 weapons including 800 and 400 licence-made in Sweden and and exported to Switzerland with the local designations Rb 27 and HM-55 respectively for service on the Saab J 35F/J Draken and Dassault Mirage IIIS fighters. The last Super Falcon missiles in the US inventory were retired in 1972, while the exported and licence-made weapons survived in Swiss, Swedish and Finnish (ex-Swedish) service into the late 1990s.

Specification

Hughes AIM-26B Super Falcon

Manufacturer: Missile Systems Group of the Hughes Aircraft Company

Type: aircraft-launched short-range air-to-air missile

Guidance: Hughes semi-active radar homing

Warhead: 40 lb (18.1 kg) active radar proximity-fused blast/fragmentation

Propulsion: one Thiokol M60 solid-propellant rocket motor rated at 5,625 lb st (25.02 kN)

Dimensions: diameter 11.5 in (0.292 m); length 6 ft 9.5 in (2.07 m); span 2 ft 0.4 in (0.62 m)

Weight: total round 262 lb (118.8 kg)

Performance: speed Mach 2; range 10,500 yards (9600 m)

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{ 1 comment… read it below or add one }

Ronald Easley January 9, 2015 at 12:42 am

Hi Chris,

I am a longtime admirer of your work. However, I must take issue with several items regarding the GAR-11/AIM-26 missile.

In the mid-1950s, the ADC-standard armament for its new missile-capable interceptors was composed of 6 x GAR-1 or GAR-2 missiles, or more usually a combination of three each. The three-missile salvos were meant to ensure a high kill probability against incoming Soviet bombers. In the case of the F-102B (later rechristened the F-106A) the greater effectiveness of the follow-on GAR-3 and GAR-4 missiles meant that a pair of each of these missiles would suffice. By then, warhead technology had advanced to the point where miniaturized nuclear air-to-air warheads were feasible, the primary result being the MB-1 Ding-Dong. This would be considered the primary air defense weapon of both the F-101B and F-106 during a general war.

The MB-1 was tested on the F-102A, from both launch rails and ejection launch systems. The MG-10 fire control systems of these test aircraft were modified with new F-pole circuits to ensure the proper timing and placement of the rocket when its W-25 warhead detonated. While the tests were deemed successful by Headquarters USAF, by that point in early 1957 the F-102A was experiencing severe teething problems in a program that was already nearly three years late. Given the austere fiscal environment of the Eisenhower years, retrofit of the MB-1 into the F-102A was too costly and would impose yet more delays.

The F-101B and F-106A were far enough behind that the MB-1 could be incorporated as an integral part of both weapon systems. However, that left ADC’s most numerous Century-series interceptor without a nuclear defense capability. Something was needed that would fit on existing launchers and otherwise be compatible with the F-102A with minimum modification to the aircraft, cost and developmental risk. Thus, the GAR-11 was born. Although I have heard rumors that its was loaded aboard a test F-101B behind closed hangar doors, I have found no direct evidence of this. As I recall, the voltage requirements for the GAR-3/GAR-4 missiles carried by the F-106 were different than for the earlier missiles, and the GAR-11 as well. I have seen no evidence that it was carried by, or considered for, the F-106. The MB-1 was considered more than adequate. In the case of the F-102A, the center missile bay doors had to be modified to remove the existing 2.75-inch FFAR tubes and, when carrying the AIM-26, could carry only one missile on the rear center rail, while the forward rails retained their triple-GAR armament, although by that point they were either GAR-2A (AIM-4C) or AIM-4D missiles.

With regard to warheads, the MB-1 was armed with a W-25 warhead, designed by Los Alamos National Laboratory and yielding 1.8 kilotons. The W-54 was a new design by a competing lab, the UC Radiation Laboratory. It had a sub-kiloton yield of about 250 tons TNT-equivalent. With regard to the AGM-62 Walleye, I have seen no evidence of its recycling and utilization in that weapon as the W-72. Chuck Hansen did not list the lab that developed the latter warhead, but he has the yield as between 5-10 kilotons, a reasonable figure for a glide bomb with limited range.

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