Landing Craft Air Cushion (LCAC)
This is the state-of-the-art hovercraft known as the LCAC, or “Landing Craft Air Cushion”. A class of air-cushion vehicle used as landing craft by the United States Navy’s Assault Craft Units and the Japan Maritime Self-Defense Force (JMSDF). The LCACs weigh 100 tonnes each and carry four gas turbine engines of 4,000 horsepower, a total of 16,000 horsepower. They transport weapons systems, equipment, cargo and personnel of the assault elements of the Marine Air/Ground Task Force both from ship to shore and across the beach. They can carry up to 75 tonnes of equipment over 20 miles. Their moto is “No Beach Out of Reach”.
The craft operates with a crew of five. In addition to beach landing, LCAC provides personnel transport, evacuation support, lane breaching, mine countermeasure operations, and Marine and Special Warfare equipment delivery. The four main engines are all used for lift and all used for main propulsion. The craft can continue to operate, at reduced capability, with two engines inoperable. They are interchangeable for redundancy. A transport model can seat 180 fully equipped troops. Cargo capacity is 1,809 sq ft (168.1 m2). The LCAC is capable of carrying a 60-ton payload (up to 75 tons in an overload condition), including one M-1 Abrams tank, at speeds over 40 knots. Fuel capacity is 5000 gallons. The LCAC uses an average of 1000 gallons per hour. Maneuvering considerations include requiring 500 yards or more to stop and 2000 yards or more turning radius. The bow ramp is 28.8 ft (8.8 m) wide while the stern ramp is 15 ft (4.6 m) wide. Noise and dust levels are high with this craft. If disabled the craft is difficult to tow. In recent years spray suppression has been added to the craft’s skirt to reduce interference with driver’s vision.
The LCAC is a dramatic innovation in modern amphibious warfare technology. It provides the capability to launch amphibious assaults from points over the horizon (OTH) from up to 50 nautical miles offshore, thereby decreasing risk to ships and personnel and generating greater uncertainty in the enemy’s mind as to the location and timing of an assault, thereby maximizing its prospects of success. The LCAC propulsion system makes it less susceptible to mines than other assault craft or vehicles. Due to its tremendous over-the-beach capability, the LCAC can access more than 80% of the world’s coastlines. Previously, landing craft had a top speed of approximately eight knots and could cross only 17% of the world’s beach area. Assaults were made from a few miles off-shore. Its high speed complements a joint assault with helicopters, so personnel and equipment can be unloaded beyond the beach in secure landing areas. For 20 years, helicopters have provided the partial capability to launch OTH amphibious assaults. Now, with LCAC, landing craft complement helos in speed, tactical surprise and without exposing ships to enemy fire.
The similarities between a Navy LCAC and an airplane are substantial. The craftmaster sits in a “cockpit” or command module with a headset radio on. He talks to air traffic control which for LCAC’s is well-deck control located near a ship’s sterngate. The ride feels like a plane in high turbulence. The craftmaster steers with a yoke, his feet are on rudder controls. The LCAC is similar to a helicopter in that it has six dimensions of motion. Operating the LCAC demands unique perceptual and psychomotor skills. In addition, with a machine as expensive and inherently dangerous as the LCAC, sound judgment and decision-making also play an important role. Concerns over escalating training cost, projections for an increased number of LCAC vehicles and crew, and a high attrition rate in training highlighted the importance of developing a more accurate means of selecting candidates. Attrition of operators and engineers has dropped from an initial high of 40% in 1988 to approximately 10–15% today.