Developed jointly by the US Air Force and US Navy starting in 1971, the AIM-9L was a vastly improved Sidewinder that was based on the H-model. The missile used All-Aspect Capability against maneuvering targets, as well as high-speed targets. The forward canards were longer in span, and of a double-delta design. Production began in 1978 with over 16,000 missiles being built by Philco-Ford, Raytheon, BGT (Germany), and Mitsubishi.
The AIM-9M replaced the L-model and featured a motor that produced less smoke, an improved guidance section that worked better against countermeasures, and improved reliability. Production began in 1982, and over 7000 of these missiles were built by Raytheon, and during Operation Desert Storm 13 aerial victories are credited to the AIM-9M. Dimensions for the L and M are identical with the missile being 9 feet, 4.5 inches long; 24.8 inches across the rear fins, and a diameter of 5 inches. Weighing in at 191 pounds (20.8 pounds belonging to the warhead), the missile can travel at over Mach 2.5 with a range of 9.7 nautical miles.