The Lockheed AC-130 gunship is a heavily-armed ground-attack aircraft variant of the C-130 Hercules. The gunship’s sole user is the United States Air Force, which uses AC-130H Spectre, AC-130U Spooky, AC-130J Ghostrider, and AC-130W Stinger II2 variants for close air support, air interdiction and force protection. Close air support roles include supporting ground troops, escorting convoys, and flying urban operations.All of the weaponry aboard is mounted to fire from the left (port) side of the non-pressurised aircraft. During an attack the gunship performs a pylon turn, flying in a large circle around the target, allowing it to fire at it far longer than a conventional attack aircraft. The AC-130H “Spectre” was armed with two 20 mm M61 Vulcan cannons, one Bofors 40mm autocannon, and one 105 mm M102 cannon.