The AIM-9 Sidewinder is a supersonic, heat-seeking, air-to-air missile carried by fighter aircraft. It has a high-explosive warhead and an active infrared guidance system. The Sidewinder was developed by the U.S. Navy for fleet air defense and was adapted by the U.S. Air Force for fighter aircraft use. Early versions of the missile were extensively used in the Southeast Asia conflict.
The AIM-9 has a cylindrical body with a roll-stabilizing near wing/rolleron assembly. Also, it has a detachable, double-delta control surfaces behind the nose that improve the missile’s maeuverability. Both rollerons and control surfaces are in a cross-like arrangement. The missile’s main components are an infrared horning guidance section, an active optical target detector, a high-explosive warhead, and a rocket motor. The infrared guidance head enables the missile to home on target aircraft engine exhaust. An infrared unit costs less than other types of guidance systems, and can be used in day or night and electronic countermeasures conditions. The infrared seekers also permits the pilot to launch the missile, then leave the area or take evasive action while the missile guides itself to the target.
The AIM-9J, a conversion of the AIM-B and E models, has maneuvering capability for dogfighting, and greater speed and range, giving it greater enhanced aerial combat capability. The AIM-9L added a more powerful solid-propellant rocket motor as well as tracking maneuvering ability. An improved active optical fuse increased the missile’s lethality and resistance to electronic countermeasures. A conical scan seeker increased seeker sensitivity and improved tracking stability. The L model was the first Sidewinder with the ability to attack from all angles, including head-on.
The AIM-9P, an improved version of the J model has greater engagement boundaries, enabling it to be launched father from the target. The more maneuverable P model also incorporated improved solid-state electronics that increased reliability and maintainability.
The AIM-9P-1 has an active optical target detector instead of the infrared influence fuse, the AIM-9P-2 added a reduced smoked motor. The most recently developed version the AIM-9P-3, combined both the active optical target detector and the reduced smoke motor. It also has added mechanical strengthening to the warhead as the guidance and control section. The improved warhead uses new explosive material that is less sensitive to high temperature and has a longer shelf life.
The AIM-9M, currently the only operational variant, has the all aspect capability of the L model, but provides all around higher performance. The M model has improved defense against infrared
countermeasures, enhanced background discrimination capability, and a reduced smoke rocket motor. These modifications increase ability to locate and lock on a target and decrease the missile’s chances for detection. The AIM-9M-9 has expanded infrared countermeasures detection circuitry. AIM-9X is a future variant currently under development.