Air Force Weapons Lab AIM-68 Big Q

In 1963, the U.S. Air Force Weapons Laboratory (AFWL) at Kirtland AFB began the a then secret program to develop a new nuclear-armed air-to-air missile, which was to be lighter and more efficient than the unguided AIR-2 Genie rocket. The original designer of the missile was given the right to choose a name, and proposed "Quetzalcoatl" (an Aztec serpent god). Not surprisingly, this caused major spelling and pronounciation troubles, and the missile became known simply as "Big Q". In March 1965, the designation ZAIM-68A was provisionally assigned to Big Q. Wind tunnel tests of 1/5-scale and full-scale models of the missile were successfully conducted in early 1965, and in May that year, a single Big Q shell powered by a solid-fueled rocket was flown at WSMR (White Sands Missile Range) as the "Little Q" test vehicle. In June 1965, National Tapered Wing Engineering Co. received a contract for 20 fuselage sections for Big Q prototype missiles (presumably to be designated XAIM-68A). The Big Q program was also referred to as "AIM-X" in the project's files, probably because the AIM-68 designation was never officially confirmed.

The AIM-68 was designed as a dual-thrust solid-propellant rocket powered missile armed with a low yield nuclear warhead (possibly a 0.5 kT W-30, but this is unconfirmed). It was equipped with a dual-mode (semi-active radar + infrared) seeker for guidance, a proximity fuze, and canards for flight control. The smaller warhead yield (when compared to the 1.5 kT of the AIR-2A Genie) and the guidance system would have made the use of the weapon against single bombers (as opposed to a whole formation) as well as maneuvering targets a lot more practicable. AIM-68 production missiles also were to use improved rocket motors and fuels, and in comparison with the AIR-2A Genie would have had speed (Mach 4 vs. Mach 3), range (40+ miles vs. 6 miles) and weight (500 lb vs. 800+ lb) advantages. The smaller yield and longer range also significantly reduced the risk of the launching aircraft to be taken out by the blast of its own weapon. It must be noted, however, that the quoted performance figures are not from official sources and could be incorrect. Potential carrier aircraft for the AIM-68 were to be the F-101B, F-106A, and possibly the F-4C. The dimensions of the missile were restricted by the requirement for internal carriage in some of these platforms. To keep size down, the Big Q design used fold-out sections for the main wings.

Drawing: USAF

ZAIM-68A

The Big Q prototypes were to use guidance sections from existing GAR-2A/B (AIM-4C/D) Falcon IR guided missiles, and rocket motors from AGM-12 Bullpup missiles. The first XAIM-68A fuselage was delivered to the AFWL in December 1965, and at that time it was expected that the first powered flight tests from a modified F-101B would occur in March 1966. However, the program suffered from low priority and some technical difficulties in modifying the F-101B, and the schedule slipped by several months. The AIM-68 program was eventually put on hold in June 1966, and officially cancelled in August that year. No flight tests of XAIM-68A prototypes were conducted. The reported reason for the cancellation was the anticipated high cost and shifts in USAF funding priorities (ICBM program, engagement in South-East Asia). Instead of replacing the AIR-2 Genie with the AIM-68, the USAF only upgraded the Genie's propulsion system.

Note: There are also sources which attribute the missile slot #68 to a "General Dynamics AGM-68", but this is definitely incorrect.

RIM-68A

In 1995, the U.S. Navy requested the designation RIM-68A for their new Standard Block IV missile, but this request was disapproved and the missile became the RIM-156A instead. In September 1995, the Navy again tried to change this to RIM-68A. It was argued that the original AIM-68A designation had been long cancelled anyway, and that RIM-68A would make a convenient consecutive sequence with the earlier RIM-66 Standard MR and RIM-67 Standard ER designations. However, the request was turned down by HQ USAF (which is responsible for official allocation of all aircraft and missile designations), because old design numbers are not to be reused even if they have been cancelled.

Specifications

Data for ZAIM-68A:

Length	2.92 m (9 ft 7 in)
Wingspan	86 cm (34 in) (wings extended)
Finspan	54 cm (21 in)
Diamater	35 cm (14 in)
Weight	225 kg (500 lb)
Speed	Mach 4
Range	> 65 km (40 miles)
Propulsion	Dual-thrust (boost/sustain) solid-fueled rocket
Warhead	W-30 nuclear fission (0.5 kT)

Main Sources

[1] Department of Defense Missile Nomenclature Records
[2] "History of the Air Force Weapons Laboratory, 1 January - 31 December 1965" (pp. 49-59, unclassified paragraphs)
[3] Weekly Activity Reports for AIM-X/AIM-68, April 1965 - August 1966
[4] Personal information from John H. McMasters, designer of the Big Q missile
[5] E-mail from Tom Cooper, Air Combat Information Group

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Last Updated: 9 June 2006