Tank origin

Designed to replace the M42 as an anti-aircraft measure, the Vulcan Air Defense System (VADS) was developed starting in 1964. At its core was a six-barreled, 20mm rotary autocannon that had also been mounted on such aircraft as the U.S. Air Force’s Lockheed F-104 Starfighter. In addition to the self-propelled version, which was known as the M163 and featured the Vulcan cannon mounted to a modified M113 chassis, a towed version of the VADS was also developed. Production of the M163 began in 1967.