1. Door gunners are an integral and efficient part of the weapons system of an armed helicopter. The door guns, one M-60 machine gun in each door, are a very effective weapon for providing suppressive fire and are considered to be 1/4th of the total weapons systems of an armed helicopter. This chapter deals with some of the techniques used by the door gunners during combat assaults, known targets, and targets of opportunity.
a. Escort for Combat Assault:
(1) A combat assault is one of the times when door gunners provide a large amount of effective suppressive fire. On lifts where slick ships are escorted, the door gunners are responsible for their respective sides and to the front of the aircraft. On combat assaults the gunner on the right side of the formation has a zone from the aircraft's one o'clock to the four o'clock position. The gunner on the inside of the formation places his fire primarily ahead of the slicks in order to avoid hitting the slicks. The most important time for the door gunner on the outside of the formation is when the armed ships break away from the formation to start their orbit. On the break the aircraft is most vulnerable to ground fire, so the door gunner on the outside of the formation must provide enough firepower to cover the aircraft as it is starting its turn.
(2) Fire Adjustment: The identifying of an enemy target and hitting it takes skill on the part of the door gunners. Usually there are two types of ammunition used by the door gunners, four to one tracer and solid tracers. The best is solid tracers, because every round may be seen and the proper amount of lag or lead may be used in order to hit the target. since the aircraft is moving faster than any of the targets, the gunner must lag or lead his target a certain distance. This distance may very with the altitude from which the gunner is firing and the speed at which the aircraft is moving. four ball to one tracer is often used because of the non-availability of solid tracer. The fire adjustment is the same as solid tracer except that one sees only one round out of five. The most effective places to put suppressive fire on combat assaults is on the tree lines that border the landing zone. The door gunner must place his fire in an area where there is a suspected enemy position. Usually tree lines are the best targets. In the event there are no tree lines, hooches near the landing zone are prime targets.
(3) Immediate Action: In the event a door gun should quit firing immediate action must be initiated. The most common malfunction will be a double feed. The best method of immediate action is to recook the fire the weapon. If this does not clear the weapon then the feed cover must be opened to find the stoppage. It may be necessary to remove the barrel in order to extract the rounds fro the chamber. In most cases, lifting the feed cover and/or recooking the weapon will clear it. Then replacing the ammunition in the feed cover will complete the immediate action.
(4) Marking Targets with Smoke: Smoke is carried in the crew member's hand by all aircraft below 1500 feet. In the event an aircraft receives fire, smoke is thrown immediately to mark the fire. During combat assaults when smoke is thrown, the door gunners are free to suppress the location where the fire came from if the location of the friendlier is known. The door gun is the best method of suppressing since it is the quickest system to employ and the door gunner has a greater view of the target to be suppressed.
(5) Attacking known targets: There are times when gun ships are not escorting aircraft into landing zones, but have known targets to attack. The use of the door gun is still one of the most effective weapons of the armed helicopter.
(6) Area of Responsibility: A fire mission is called and the target is pointed out to the door gunners. A firing pass is then made and both door gunners place their fire in the vicinity of the target. When the aircraft breaks before it reaches the target, the door gunner on the outside of the turn must cover the aircraft. This door gun is the only weapon the gun ship has to cover the exposed aircraft during a break.
(7) Fire Adjustment: Fire adjustment remains the same as attacking the known target during combat assaults. The door gunner must lag or lead the target. He uses tracers to adjust the fire. Also, in the event of a stoppage, the immediate action remains the same as described earlier.
b. Targets of Opportunity: There is one more instance when the door gunner is most effective for providing immediate and effective fire, and this is a target of opportunity. The target of opportunity may occur during combat assaults or while the fire team is providing overhead cover on a fire team mission.
(1) Marking with smoke: Targets of opportunity usually start with an aircraft dropping smoke. On combat assaults the door gunners quickly place their fire in the vicinity of the smoke, when the position of the friendlies is known. The door gunner places his fire in tree lines and hooches that are suspected enemy targets and uses the lag or lead method of adjustment with the aid of his tracers. If a stoppage occurs, then the door gunner uses the immediate action to clear his weapon and continues his mission.
(2) Fire Adjustment: While the fire team is flying their mission and one of the gun ships receives fire, the aircraft receiving fire throws smoke and tells the fire team leader he has received fire. If the target is clear for suppressive fire, then the door gunner immediately takes the suspected targets under fire. If the fire isn't definite then a fire mission is called on the vicinity of the smoke and the target then becomes a known target and the door gunners apply the techniques described earlier to effectively attack and suppress the target.