The Vympel K-13 (NATO reporting name: AA-2 "Atoll") is a short-range, infrared homing air-to-air missile developed by the Soviet Union. It is similar in appearance and function to the American AIM-9B Sidewinder from which it was reverse-engineered. Although it since has been replaced by more modern missiles in frontline service, it saw widespread service in many nations. Background - the Sidewinder missile During the Second Taiwan Strait Crisis in 1958, Taiwan's F-86 Sabres faced the much higher performance mainland Chinese PLAAF MiG-17s. The MiG-17s had speed, maneuverability, and altitude advantages over the Sabres, allowing them to engage only when they desired, normally at advantageous times. In response, the US Navy rushed to modify 100 ROCAF Sabres to carry the newly introduced AIM-9 Sidewinder missile. These were introduced into combat on 24 September 1958, when a group of MiG-17s cruised past a flight of Sabres, only to find themselves under attack by missile fire. This was the first instance of guided missiles being used in air-to-air combat. On 28 September 1958, a similar engagement resulted in one of the missiles becoming lodged in a MiG-17 without exploding, allowing it to be removed after landing. The Soviets later became aware that the Chinese had at least one Sidewinder, and after some wrangling, were able to persuade the Chinese to send them one of the captured missiles. Gennadiy Sokolovskiy, later chief engineer at the Vympel team, said that "the Sidewinder missile was to us a university offering a course in missile construction technology which has upgraded our engineering education and updated our approach to production of future missiles." A subsequent claim was made by Ron Westrum in his book Sidewinder that the Soviets obtained the plans for the Sidewinder from Swedish Colonel and convicted spy Stig Wennerström, and rushed their version into service by 1961 copying it so closely that even the part numbers were duplicated. Although Wennerström did leak information of the Sidewinder after negotiating its purchase for Sweden, none of the known Soviet sources mention this, while all explicitly mention the Chinese example. Development and early use The Sidewinder was quickly reverse engineered as the K-13 (also called R-3 or Object 300) and entered limited service only two years later in 1960. This was followed by the improved K-13A (R-3S, Object 310), which entered service in 1962. The R-3S was the first version to enter widespread production, in spite of a