The AIM-9 Sidewinder is an infrared-homing, short range air-to-air missile, which can be used by fighter aircraft and attack helicopters. During the operational history of the Sidewinder, which lasts since over 50 years, more aircraft were downed with the Sidewinder, than with any other missile, it is estimated that over 270 kills were achieved. A modified Sidewinder variant is used by the MIM-72 Chaparral anti-aircraft system. Being an infrared-guided missile, the NATO brevity code for the launch of an AIM-9 is Fox Two.
The Sidewinder has a highly explosive warhead and an infrared sensor for target detection. The Sidewinder’s guidance system was designed to lock on to the hot exhaust of aircraft engines or anything else that shows similarities with an engine. With a price of 85,000 US-Dollars, the Sidewinder is relatively cheap and it has limited all-weather capabilities. The Sidewinder is a Fire-and-Forget missile, meaning that it is able to destroy a target on its own after lock-on.