In the Mekong Delta, the Patrol Air Cushion Vehicle (PACV), also known as the Air Cushion Vehicle (ACV) helped the US Army perform patrol, reconnaissance and cargo missions from 1966 to 1970.
The Patrol Air Cushion Vehicle, or PACV, was based on the Bell Aerosystems SK-5 hovercraft. The terrain of the Mekong Delta and the battlefields of Vietnam, was the ideal test ground for this vehicle. It was here that the United States gained its first and only experience to date in the use of Air Cushion Vehicles in combat.
In the field of hovercraft, the US is not the pioneer. The first such vehicles were used by the British in suppressing insurgent forces in Malaysia in the 1950s. In 1965, based on these experiences, the US Navy decided to buy three SR.N5 hovercraft from the UK. In the US, these vehicles were modified by Bell Aerosystems at the request of the US Navy. They were also armed to increase their power.
Work was completed in 1966. Crew training was carried out in the United States. In May 1966, the first Patrol Air Cushion Vehicles were deployed in Vietnam. The US Navy has used these vehicles to patrol the Mekong Delta and coastal areas. PACV was particularly useful in shallow and swampy areas where river patrol boats were inaccessible.
PACV was much larger than the standard PBR Mk.2 river patrol boats. The total displacement of PACV was 7.1 tons; The length was 11.84 m, the width was 7.24 m, and the height was 5 m. The hovercraft was manned by a crew of four, a driver, a commander and radar operator, and two machine gunners. In addition, each vehicle could carry up to 12 soldiers with full weapons.
PACV was equipped with a General Electric 7LM100-PJ102 gas turbine engine, with a maximum capacity of up to 1,100 horsepower, for a maximum speed of 60 knots (about 110 km/h). The fuel tank was 1,150 liters, enough to covered a distance of 165 nautical miles (about 306 km). Patrol cruise endurance was about 7 hours.
After being upgraded, PACV was heavier and better armored than the original. The total weight of the armor was 450 kg, equivalent to that of the M113 armored vehicle. The gearbox, engine and fuel tank were also armored, able to withstand 12.7 mm bullets from a distance of over 180 meters. PACV’s cabin was less armored, so it was constantly damaged by 7.62 mm bullets. At the request of the US military, the armor around the cabin compartment was removed to reduce weight, as it did not provide any special protection, especially against heavy weapons.
PACV’s main armament were two 12.7 mm M2 Browning machine guns on the roof. Secondary armament was two 7.62 mm M60 machine guns on either side, similar to those installed on armed helicopters. In addition, it could also be equipped with the M75 40 mm automatic grenade launcher.
PACV was used by the US Marines in Vietnam from 1966 to 1970. However, their effectiveness was not as expected, because their operation was too expensive, unreliable, and required high technical maintenance. Later, the US had to withdraw the air-cushioned vehicles from the Vietnam battlefield, partly due to the effective coping tactics of the Liberation Army.
The firepower of the hovercraft was also said to be insufficient. The US Army offered to upgrade weapons with 20 mm automatic cannons, or 6-barreled M61 Vulcan cannons, anti-tank missile systems or M40 106 mm recoilless guns. However, these suggestions were not implemented. Only 3 PACVs were built and sent to the Vietnam battlefield, one of them was destroyed by the Liberation Army. In 1970, the US decided to stop the operation of these hovercraft. They were sent back to the US and transferred to the US Coast Guard.