0 ▁Spect re ▁gun ship . ▁ ▁It ▁was ▁the ▁later ▁and ▁larger ▁Lock he ed ▁AC - 1 3 0 ▁Gun ship ▁II ▁that ▁became ▁the ▁modern , ▁post – World ▁War ▁II ▁origin ▁of ▁the ▁term ▁gun ship ▁in ▁military ▁av iation . ▁These ▁heavily ▁armed ▁aircraft ▁used ▁a ▁variety ▁of ▁weapon ▁systems , ▁including ▁ 7 . 6 2   mm ▁G AU - 2 / A ▁Min ig uns , ▁ 2 0   mm ▁( 0 . 7 8 7   in ) ▁M 6 1 ▁V ul can ▁six - bar rel ▁rot ary ▁can n ons , ▁ 2 5   mm ▁( 0 . 9 8 4   in ) ▁G AU - 1 2 / U ▁Equ al izer ▁five - bar re led ▁rot ary ▁can n ons , ▁ 3 0   mm ▁M k 4 4 ▁Bush master ▁II ▁chain ▁guns , ▁ 4 0   mm ▁( 1 . 5 8   in ) ▁L / 6 0 ▁B of ors ▁aut oc ann ons , ▁and ▁ 1 0 5   mm ▁( 4 . 1 3   in ) ▁M 1 0 2 ▁how itz ers . ▁The ▁Douglas ▁AC - 4 7 ▁Spo ok y , ▁the ▁Fair child ▁AC - 1 1 9 , ▁and ▁the ▁AC - 1 3 0 ▁Spect re / S po ok y , ▁were ▁vulner able , ▁and ▁meant ▁to ▁operate ▁only ▁after ▁ach ieving ▁air ▁superior ity . ▁▁