AIM-9 Sidewinder

Mission
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 infrared heat-seeking 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.

Features
The AIM-9 has a cylindrical body with a roll-stabilizing rear wing/rolleron assembly. Also, it has detachable, double-delta control surfaces behind the nose that improve the missile's maneuverability. Both rollerons and control surfaces are in a cross-like arrangement.

The missile's main components are an infrared homing guidance section, an active optical target detector, a high-explosive warhead and a rocket motor.

The infrared guidance head enables the missile to home in on target aircraft engine exhaust. An infrared unit costs less than other types of guidance systems, and can be used in day/night and electronic countermeasures conditions. The infrared seeker also permits the pilot to launch the missile, then leave the area or take evasive action while the missile guides itself to the target.

Background
The AIM-9A, a prototype of the Sidewinder, was first fired successfully in September 1953. The initial production version, designated AIM-9B, entered the Air Force inventory in 1956 and was effective only at close range. It could not engage targets close to the ground, nor did it have nighttime or head-on attack capability. These shortcomings were eliminated on subsequent versions.

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. Deliveries began in 1977 to equip the F-15 and other Sidewinder-compatible aircraft.

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. Production and delivery of the AIM-9L began in 1976.

The AIM-9P, an improved version of the J model, has greater engagement boundaries, enabling it to be launched farther from the target. The more maneuverable P model also incorporated improved solid-state electronics that increased reliability and maintainability. Deliveries began in 1978.

The AIM-9P-1 has an active optical target detector instead of the infrared influence fuse; the AIM-9P-2 added a reduced-smoke 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 well 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 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. Deliveries of the M model began in 1983.

The AIM-9M-9 has expanded infrared countermeasures detection circuitry.

AIM-9X is the newest variant of Sidewinder. The AIM-9X has the same rocket motor and warhead as the AIM-9M. Major physical changes from previous versions of the missile include fixed forward canards, and smaller fins designed to increase flight performance. The guidance section has been redesigned and features an imaging infrared seeker. The propulsion section now incorporates a jet-vane steering system for enhanced post-launch agility. The X model is also compatible with the Joint Helmet-Mounted Cueing System, which is designed for ease of target acquisition and decreased aircrew workload.

General Characteristics
Primary Function:
Air-to-air missile
Contractor: Raytheon and Loral Martin
Power Plant: Hercules and Bermite Mk 36 Mod 11
Length: 9 feet, 5 inches (2.87 meters)
Diameter: 5 inches (0.13 meters)
Finspan: 2 feet, 3/4 inches (0.63 meters)
Warhead: Annular blast fragmentation warhead
Launch Weight: 190 pounds (85.5 kilograms)
Guidance System: Solid-state, infrared homing system
Introduction Date: 1956
Unit Cost:  Variable, depending on lot, quantity and block
Inventory: Classified