▁Sm aller ▁gun ship ▁designs ▁such ▁as ▁the ▁Fair child ▁A U - 2 3 ▁Pe ac em aker ▁and ▁the ▁Hel io ▁A U - 2 4 ▁St all ion ▁were ▁also ▁designed ▁by ▁the ▁United ▁States ▁during ▁the ▁Vietnam ▁War . ▁These ▁aircraft ▁were ▁meant ▁to ▁be ▁cheap ▁and ▁easy ▁to ▁fly ▁and ▁maintain , ▁and ▁were ▁to ▁be ▁given ▁to ▁friendly ▁govern ments ▁in ▁S out heast ▁Asia ▁to ▁assist ▁with ▁counter - ins ur gency ▁operations , ▁eventually ▁seeing ▁service ▁with ▁the ▁Kh mer ▁National ▁Air ▁Force , ▁Royal ▁Th ai ▁Air ▁Force , ▁and ▁Republic ▁of ▁Vietnam ▁Air ▁Force ▁as ▁well ▁as ▁limited ▁use ▁by ▁the ▁United ▁States ▁Air ▁Force . ▁ ▁Ren ew ed ▁interest ▁in ▁the ▁concept ▁of ▁gun ships ▁has ▁resulted ▁in ▁the ▁development ▁of ▁a ▁gun ship ▁variant ▁of ▁the ▁Al enia ▁C - 2 7 J ▁Spart an . ▁Although ▁the ▁United ▁States ▁Air ▁Force ▁decided ▁not ▁to ▁proc ure ▁the ▁AC - 2 7 J , ▁other ▁nations ▁including ▁Italy ▁have ▁chosen ▁the ▁aircraft ▁for ▁introduction . ▁Additionally , ▁in ▁ 2 0 1 3 ▁the ▁US ▁Air ▁Force ▁Special ▁Oper ations ▁Command ▁reported ly ▁tested ▁a ▁gun ship ▁version ▁of ▁the ▁C - 1 4 5 A ▁Sky tr uck ▁armed ▁with ▁a ▁G AU - 1 8 ▁tw in - mount ▁. 5 0 - cal ib re ▁machine ▁gun ▁system . ▁ ▁Hel ic opter ▁gun ships ▁Early ▁hel ic opter ▁gun ships ▁also ▁operated ▁in ▁the ▁side -