The Hughes GAR-9/AIM-47 was a long-range development of the AIM-4 Falcon air-to-air missile. It was developed in 1958, matched with the new Hughes AN/APG-18 radar fire-control system intended to arm the XF-108 Rapier interceptor aircraft. The missile was originally designated GAR-9.

The GAR-9 was powered by a liquid-fuel rocket engine. A nuclear warhead was considered, but a large high-explosive warhead was chosen instead. Initially launch was semi-active radar homing (SARH), with the missile flying to the target area by autopilot, receiving (if necessary) mid-course updates provided by the launch aircraft. A choice of active radar or infrared homing was developed for the terminal guidance phase. It was intended to fly at Mach 6, with a range of some 130 mi (210 km).

The XF-108 was cancelled, but development of the radar and missile (which was redesignated AIM-47 in the fall of 1962) continued. The AN/APG-18 and AIM-47 were the intended weapon system of the Lockheed YF-12 interceptor, which would have carried a projected AIM-47B version with folding wings. That, too, was cancelled by 1966. Hughes had built some 80 pre-production missiles, however, and the technology was used in the development of the AIM-54 Phoenix for the US Navy.