The AIM-26 Falcon was a larger, more powerful version of the AIM-4 Falcon air-to-air missile built by Hughes. It is the only guided American air-to-air missile with a nuclear warhead to be produced; the unguided AIR-2 Genie rocket was also nuclear-armed.
Starting in 1956 Hughes Electronics began the development of an enlarged version of the GAR-1D Falcon that would carry a nuclear warhead. It was intended to provide a sure kill in attacks on Soviet heavy bomber aircraft, at a time when guided missiles were not accurate enough to produce high-probability kills with small conventional warheads. The original development was for semi-active radar homing and heat-seeking versions based on the conventional GAR-1/GAR-2 weapons, under the designations GAR-5 and GAR-6, respectively. The original program was cancelled.
The program was revived in 1959, now under the name GAR-11. It entered service in 1961, carried by Air Defense Command F-102 Delta Dagger interceptors. It used a radar proximity fuze and semi-active radar homing. The GAR-11 used a sub-kiloton (250 ton) yield W54 warhead shared with the "Davy Crockett" M388 recoilless rifle projectile, rather than the larger W25 warhead of the AIR-2 Genie.
Out of concern for the problems inherent in using nuclear weapons over friendly territory, a conventional version, the GAR-11A, was developed, using a 40lb explosive warhead.
As part of a wider Army/Navy/Air Force renaming project, in 1963 the weapon was redesignated AIM-26. The nuclear version became the AIM-26A, the conventional model the AIM-26B. From 1970 to 1972 the nuclear warheads of the AIM-26A weapons were rebuilt for the nuclear version of the AGM-62 Walleye TV guided bomb.
The AIM-26 saw little widespread use in American service, retiring in 1972. The conventional AIM-26B was exported to Switzerland as the HM-55, where it was used on Swiss Mirage IIIS fighters. The AIM-26B was produced under license (and modified) in Sweden as the Rb 27, arming Saab Draken J-35F and 35J fighters. It was retired in 1998. When Finland bought Drakens, the license-manufactured Swedish Falcons were included.
Below is an incomplete list of museums which have an AIM-26 in their collection: