The Sidewinder AIM-9 is a supersonic, heat-seeking, short range, air-to-air missile capable of being launched from a vast array of aircraft types. The Sidewinder’s main components are an infrared (IR) homing guidance section, an active optical target-detector, a high-explosive warhead and a rocket motor. The in-built IR seeker allows the pilot to launch the missile, then leave the area, or take evasive action, while the missile guides itself to impact by homing on the engine exhaust of the target aircraft. IR homing allows the missile to be used by day or by night and in electronic countermeasure conditions. The Sidewinder is the most widely used air-to-air missile in the world and is one of the oldest, least expensive and most successful missiles ever produced.

The Sidewinder has been continually updated over the years and the AIM-9L and AIM-9L/I versions used by the RAF have enhanced guidance characteristics, which give them the ability to attack targets from all angles, including head-on. Installation of a conical scan-system increased the seeker’s sensitivity, improved tracking stability and gave the missile a much improved resistance to IR decoys.

The Sidewinder is a within-visual-range missile, slaved to the target either manually by the pilot, or by using one of the aircraft’s sensors. It is a ‘dogfight’ missile and so launches and arms itself very quickly, thus allowing it to be employed at very short range. Once launched, the missile is guided to the target using IR homing and the annular blast-fragmentation warhead is detonated once the target is inside the missile’s lethal radius. The Sidewinder is a fire-and-forget missile, allowing the pilot to fire several missiles at different targets within a very short time frame.