CH-47 in Vietnam War
The CH-47 Chinook was first committed to action in Vietnam during 1965 and quickly proved to be dependable, highly adaptable to the adverse weather conditions in Vietnam and capable of hauling tremendous loads into hostile areas, often under fire, and surviving. The 1st Cavalry Division deployed with their organic CH-47 Battalion to Vietnam in September of 1965, and by year send, the division’s Chinooks had amassed thousands of flight hours and had successfully recovered over 100 downed aircraft.
During that year, the Department of Defense ordered production of the CH-47 doubled to meet the expanded requirements of Army airmobile units in Vietnam. Appropriately nicknamed the ‘Hook’ by the troops in the field, the CH-47 quickly proved to be an invaluable tool for artillery movement and heavy supply lifts. The Chinook was seldom used for its intended role, that of an assault troop carrier; that mission being undertaken primarily by the smaller and more maneuverable UH-1 Huey. When the Chinook did transport troops into combat, however, lifts of up to seventy-five Vietnamese soldiers on a single flight were not uncommon. One of the primary missions of theCH-47 in Vietnam was the emplacement of artillery batteries at remote mountain fire bases and keeping these bases well supplied with ammunition.
Chinook Equipment and Armament
The normal crew complement of a CH-47 in combat consisted of a pilot, copilot, flight engineer/crew chief (who also doubled as a gunner), and gunner. To prepare the aircraft for combat the crews removed the rear cabin windows (and sometimes other windows as well) to create gun ports for use by the onboard troops. The standard armament fitted to CH-47s in Vietnam was a pintle-mounted 7.62mm M60D machine gun in the port side escape hatch opening and a second M60D on a swing out mounting in the forward starboard crew door. Designated the XM-24, this armament subsystem contained mechanical stops to prevent the gunners from inadvertently firing into the rotors or fuselage during the heat of combat. The M60s were equipped with bipods and could be easily removed from their quick-release mountings for use as ground weapons in the event the CH-47 was shot down.
To prevent damage to the rotors and engines, a canvas bag was attached to the starboard side of each gun to catch ejected shell casings and links. A 200 round ammunition box was fitted to the port side of the M60, although these were usually removed in favor of much larger containers, depending on the unit policy or crew preference. Some units rigged flexible ammunition chutes (borrowed from 7.62mm Minigun mounts) which were fed by large ammunition boxes lashed to the cargo floor. The XM-24 subsystem had a rate of fire of 550 to 600 rounds per minute (rpm) and an effective range of 1.500 meters.
Although not as commonly used, the XM-41 subsystem incorporated an M60D or .50 cal. machine gun mounted on a pintle-mount on the rear cargo ramp, firing out of the open ramp. This system was first tested during mid-1967 and saw some limited use as an area fire suppression weapon when exiting a hot landing zone.
In addition to the weapons, the radio equipment fitted to Vietnam based CH-47s was also enhanced. KM radios, used to communicate with ground units, were installed and the aircraft were modified with wire antenna mounting spikes on the port fuselage side. A number of aircraft also carried a pair of FM whip antenna mounts on the nose. These communications modifications were made to all variants that saw service in Vietnam (CH-47 As, CH-47Bs and CH-47Cs) and were performed at the unit or depot level.
At the height of the war, some twenty-two Chinook units were in operation, performing a variety of missions in support of the war. One of the vital missions was the recovery of downed aircraft, known as Pipesmoke missions. Chinooks were used to salvage so many downed aircraft that the CH-47 became the Army’s primary recovery vehicle. Over the course of the war, CH-47s were credited with the recovery of 11,500 disabled aircraft worth more than three billion dollars. Equally important was the Chinooks use in the civic action effort which often required the rapid movement of an entire village to a safe location. During one such airlift a Chinook lifted 147 Vietnamese and their possessions in a single flight!
‘Hooks’ also proved invaluable for supplying fuel to remote areas. For these operations the 3,500 pound. 500 gallon rubberized fuel cells, known as blivets, were carried as external cargo, suspended from the CH-47 s external cargo hook.
Chinook during Operation PERSHING
During Operation PERSHING during 1967, the 1st Cavalry Division used Chinooks to drop a total of 30,000 pounds of tear gas agents on enemy positions. The CH-47s used a simple locally fabricated fusing system which was mounted on a standard fifty-five gallon gas drum. The drums were rolled off the rear cargo ramp and the fuse was armed by a static line, exploding a pre-determined distance off the ground and spreading the tear gas over a wide area. During this same time period, napalm drums were fused and dropped in a similar manner. A single CH-47 Chinook could lay down two and one half tons of napalm in a single drop, making it a highly effective weapon against Viet Cong tunnels.