The M163 provides mobile, short-range air defense protection for ground units against low-flying fixed-wing aircraft and helicopters.

[5] In US and Israeli service, the VADS has rarely been needed in its intended purpose of providing defense against aerial threats—consequently, the Vulcan gun system was in use throughout the late 1980s and early 1990s primarily as a ground support weapon.

In order to provide effective battlefield air defense against helicopters equipped with anti-tank missiles that could be fired accurately from ranges of several kilometers, the VADS was slated to be replaced by the M247 Sergeant York DIVADS (Divisional Air Defense System), but that system was canceled in August 1985 due to cost overruns, technical problems, and generally poor performance.

The final US Army VADS-equipped unit at Fort Riley Kansas completed turn-in of its Vulcans in 1994.

[11] PIVADS units could use Mk 149 APDS rounds, which greatly increase maximum effective range due to their higher velocity and lack of a self-destruct.