Benign aircraft has always proved useful for modification to the military. During the Southeast Asian War, such benign cargo planes were modified into some of the most extraordinary and destructive weapon systems of all time. The hastily improvised AC-47 "Spookies" roamed the night skies of South Vietnam, defending outposts against lethal enemy assaults with blazing fire from three side-mounted guns. The success of these makeshift gunships led to the creation of more sophisticated airborne predators, such as the AC-130.The airframe is manufactured by Lockheed Martin, while Boeing is responsible for the conversion into a gunship and for aircraft support. Developed during the Vietnam War as "Project Gunship II", the AC-130 replaced the Douglas AC-47 Spooky, or "Gunship I".