Door gunner < br > A door gunner is a crewman tasked with firing and maintaining manually directed armament aboard a helicopter . The actual role will vary depending on the task given on a particular mission . Origins . The concept of the " door gunner " originated during the Vietnam War , when helicopter s were first used in combat in large numbers . The original personnel who served as early door gunners aboard CH - 21 , UH - 34 , and UH - 1 helicopters in Vietnam , were enlisted men , with a designated and specially trained " crew chief " serving as both the aircraft ' s maintenance manager and a door gunner . Normally , a second enlisted soldier served as a second door gunner ( such as on a UH - 1 , and UH - 34 , which both used two gunners – one on each side of the aircraft ) . Later , as the war progressed , the door gunner position sometimes used a non - aviation rated / trained soldier or marine , that volunteered for door gunner duties . For the majority of the Vietnam war , the principal weapon of the door gunner was a medium machine gun ( MG ) , initially , a M - 1919A4 . 30 caliber MG , and soon thereafter , the M - 60 7 . 62mm MG became the standard helicopter door armament system . Initially however not all helicopters were armed or outfitted with a dedicated MG for door armament . For example the very first U . S . Army helicopter units , flying CH - 21 helicopter s , that began flying combat missions in Vietnam in 1962 didn ' t . Therefore door gunners on Vietnam photographs are sometimes seen using an M1 Carbine , an M14 rifle , or an M16 rifle , as their only weapon . Initially , the door gunner ' s MG weapons were mounted on swiveling mounts ( on a pintle mount ) in order to retain and steady the door armament weapon . As the war progressed , using bungee cord s to suspend / retain the MG became a common practice , as the newfound maneuverability of these " bungeed " weapons allowed for increased firing angle s . However some door gunners simply continued to hand - wield the weapon for a maximum level of maneuverability of fire . This practice was commonly termed as using a " Free 60 " . Door gunners were normally restrained for safety within the aircraft , by either using a standard lap belt , or if the gunner wanted freedom of movement within the aircraft while still being retained , he used a " monkey harness " , which was a GI safety harness worn on the torso , and anchored to the aircraft floor , or cabin wall . The monkey harness allowed a door gunner great movement , including to lean outward on the helicopter skids , to get a better firing angle . The door gunner position was not a particularly popular one , due to the exposed position of manning a machine gun in the open door of a helicopter . According to popular legend , the door gunner on a Vietnam era Huey gunship had a life - span of 5 minutes . This was obviously exaggerated but displays the hazards of this particular military job at the time . Today , helicopters like the UH - 60 have two machine gun s firing out of two windows located behind the pilots . The CH - 46 , CH - 47 and CH - 53 have an additional gun that is fired from the rear ramp . The UH - 1 ( still in use by the U . S . Marine Corps , as the UH - 1Y ) is still manned as it was in the Vietnam War , with the gunner firing from the open cabin door . The Modern Door Gunner . U . S . Navy door gunners now provide stand off security against attack by small craft . U . S . Army crew chiefs in UH - 60 and CH - 47 units serve as gunners in addition to their maintenance duties . Today , the term " door gunner " usually applies to those personnel that aren ' t qualified crew chiefs and thus don ' t fly operationally ( the exception would be maintenance personnel that are on flight status for test flight purposes in the aviation maintenance company within aviation battalions ; in this case these personnel don ' t fly often ) . The modern door gunners are normally drawn from support soldiers within the aviation battalion , detailed from his or her company to one of the flight companies within the battalion . Upon notification of an upcoming deployment to a hostile fire zone , an aviation unit is allowed to select and train personnel assigned to the unit for the duration of the deployment ( flight status is terminated upon completion of the deployment ) . They normally undergo a specified training period ( normally referred to as a " progression " ) and then assume part - time or , in some cases dependent on the needs of the companies and the battalion as a whole , full - time flying duties . Duties range from preparation of the machine guns ( typically M240 model weapons ) , performing inflight observer duties , and assisting the crew chief with maintaining the aircraft . After completing a certain number of combat missions Army door gunners are eligible for the award of the Army Aviation Badge . Helicopters from the U . S . Coast Guard Helicopter Interdiction Tactical Squadron ( HITRON ) use door gunners armed with sniper rifles to disable suspect vessels . Equipment . Most door gunners use some sort of machine gun such as the M60 , M240 , M2HB , or more recently , the General Electric M134 minigun