The Assault Amphibious Vehicle (AAV)—official designation AAV7 (Assault Amphibious Vehicle, Model 7), formerly known as LVT7 (Landing Vehicle, Tracked, Model 7)—is a fully tracked amphibious landing vehicle manufactured by BAE Systems Platforms & Services (previously by United Defense, a former division of FMC Corporation).
The AAV7 was the primary amphibious troop transport of the United States Marine Corps from the 1970s until the first half of the 2020s. It was used by U.S. Marine Corps Amphibious Assault Battalions to land the surface assault elements of the landing force and their equipment in a single lift from assault shipping during amphibious operations to inland objectives and to conduct mechanized operations and related combat support in subsequent mechanized operations ashore. It is also operated by other forces. Marines call them "amtracs", a shortening of their original designation, "amphibious tractor".
In June 2018, the Marine Corps announced they had selected the BAE Systems/Iveco wheeled SuperAV for the Amphibious Combat Vehicle (ACV) program to supplement and ultimately replace the AAV. The AAV7 was eventually retired from U.S. Marine Corps service in May 2025.
History Development
The U.S. Marine Corps became interested in replacing the LVTP-5 due to its limited range, slow water speed and the difficulty of maintaining the aging platform. In 1964, the Marine Corps solicited proposals to replace meet its requirement. The request was met by proposals from Chrysler and FMC, with the latter being awarded the contract in February 1966. Twelve prototypes of the new vehicle, designated LVTPX12, were delivered by FMC in summer 1967. It was also proposed in four variants, including the LVTCX2 command vehicle, LVTRX2 recovery vehicle, LVTEX3 engineering vehicle, and LVTHX5 fire-support vehicle. Of the four variants, only three were constructed: one LVTCX2 in 1969, and two LVTRX2s and two LVTEX3s in 1970.
The prototypes were powered by a Detroit Diesel 8V53T engine coupled to an FMC HS-400 transmission. The engine developed 400 gross horsepower at 2,800 rpm and could propel the vehicle at speeds of up to 40 mph on land, or up to 8.4 miles per hour in water using two water jets. All three variants had a crew of 3, while the LVTPX12 personnel carrier could carry a further 24 troops plus a troop commander. The LVTPX12, LVTCX2, and LVTEX3 were each armed with a weapon station containing a 20 mm M139 cannon and 7.62 mm M73E1 machine gun, although some of the prototypes were later re-armed with a weapon station consisting of a single .50 caliber M85 machine gun. The LVTEX3 was further equipped with three rocket-propelled line charges mounted within the rear of the vehicle and was also fitted with a dozer blade. The LVTRX2, meanwhile, was unarmed, replacing the weapon station with a cupola with vision blocks, and was equipped with a 30,000-lb winch and 6,000-lb crane. The LVTHX5 was proposed with a 105 mm howitzer in a turret but was never built.
Marine Corps testing occurred at Aberdeen Proving Ground, Yuma Proving Ground, Fort Greely, and in Panama, from 1967 through June 1970. A $10.4 million contract for low-rate initial production (LRIP) was awarded to FMC in May 1970 for 38 vehicles, which was followed in June by a $78.5 million contract for full-scale production of 942 vehicles.
Four of the five models were type-classified: The LVTPX12 became the LVTP7, the LVTCX2 became the LVTC7, the LVTRX2 became the LVTR7, and the LVTEX3 became the LVTE7, although the latter never entered production. The first production models of the LVTP7 were delivered in August 1971 and the first units became operational in March 1972. Production models were largely similar to their prototypes, with the most notable change being the .50 caliber M85 weapon station being standardized in favor of the 20 mm M139. A total of 942 or 971 LVTP7s, 84 or 85 LVTC7s, and 55 or 58 LVTR7s were constructed by FMC starting in 1971. Production of the LVT7 family of vehicles ended in April 1974.
Compared to the LVT5/6 family, the LVT7 family was far more maneuverable and faster in water in large part due to the use of water jets instead of tracks for propulsion. It also featured a rear-opening ramp, unlike the front ramp on the LVT5, and was constructed from 5083 aluminum armor, offering comparable protection to the M113. It also used a conventional torsion bar suspension instead of the Torsilastic suspension found on previous LVT models dating back to WWII.
Service Life Extension Program The planned service life of the LVT7 family of vehicles was only 10 years. However, it was understood that a completely new vehicle would not be ready until the late 1990s or early 2000s. As such, the LVT7's Service Life Extension Program (SLEP) was initiated in 1982 to keep the vehicle in service until at least 1994. Upgraded SLEP models were given the designations LVTP7A1, LVTC7A1, and LVTR7A1, respectively.
The LVT7A1 SLEP program included: A new Cummins VT-400 liquid-cooled turbocharged V8 diesel engine, developing 400 hp at 2,800 rpm The improved FMC HS-400-3A1 transmission A new electrically-driven weapon station for the M85 machine gun The new weapon station also featured eight M257 smoke grenade launchers On the LVTC7A1, the weapon station was replaced by an unarmed cupola, as on the LVTR7/A1 Upgraded suspension, featuring more and improved shock absorbers Replaced integral fuel tanks with non-integral fuel tanks, reducing the risk of damage from hull flexion A new instrument panel for the driver Added an exhaust smoke generation system Allowed for the tracks to be engaged while water jets were in operation, improving trim New communication systems for the LVTC7A1 A night vision device for the driver A new ventilation system Improved seals and drains
The SLEP program was primarily focused on the rebuild of existing vehicles. A total of 853 LVTP7s (according to another source, all LVTP7s), 77 LVTC7s, and 54 LVTR7s were converted to A1 standard. Furthermore, from 1983 to 1985, 333 new LVT7A1s were built as part of the program (294 LVTP7A1, 29 LVTC7A1, and 10 LVTR7A1) and purchased at a unit cost of $850,000 each. New-production AAV7A1s are distinguishable by their new headlight arrangement in a rectangular recess instead of the circular design of the original.
In 1984, the LVT7 family of vehicles was redesignated to AAV7, creating the AAVP7A1, AAVC7A1, and AAVR7A1.
Mine-clearance systems In the early 1980s, the AAVP7A1 also received mine-clearance systems which could be installed in the troop compartment or towed behind the vehicle. These matched the engineering abilities of the LVTE7, which had not entered production.
Mine-clearing line charges (MICLICs), namely the AAV-mounted Mk 154 and trailer-mounted Mk 155, were the primary mine clearance system used by the AAVP7A1. The Mk 154 contains three rocket-propelled line charges which are installed in the troop compartment of the AAVP7A1. The line charges contain 1,750 pounds of C-4 explosive and are capable of clearing a 100-meter long, 16-meter wide lane through a minefield.
MICLIC-equipped AAVP7s are found within the Mobility/Countermobility (MCM) Platoon of the Headquarters and Service (H&S) Company of an Assault Amphibian Battalion. Twelve vehicles are accompanied by 12 standard variants acting as support.
In 2013, the system was deadlined following the death of a marine during a training accident, but was returned to service in 2017 as the Mk 154 Mod 1 variant, which incorporated significant safety improvements.
CATFAE In the late 1980s, the Catapult-Launched Fuel-Air Explosive (CATFAE) surf zone mine clearance system was also developed. Operating on a similar principle to the earlier MICLIC, the CATFAE fitted 21 fuel-air explosive rounds in the troop compartment that could be launched to destroy mines or other obstacles, particularly in shallow water. The system was capable of breaching a 20 m by 300 m area through a minefield while moving up to 6 knots (in water) or 15 mph (on land).
CATFAE entered Full Scale Engineering Development on 30 March 1989, with Initial Operating Capability scheduled for Q4 FY1995. The project was ultimately terminated before it entered service.
Mine plow In conjunction with the acquisition of explosive mine clearance systems, mine plows were also procured for the AAV. In early 1989, Caterpillar won a $1.4 million contract to develop four prototype track-width mine plows. The plow could be controlled by a panel in the driver's compartment, with which it could be raised, lowered, and jettisoned. Developmental testing was scheduled for Q3 FY1990, operational testing in Q4, and Initial Operating Capability (IOC) in 1993. As of 1990, the acquisition objective (AO) was 168 units. However, it appears this project was also terminated before any examples entered service.
Product Improvement Program Immediately following the SLEP, a Product Improvement Program (PIP) was initiated in 1985 in order to extend the AAV7's service life until 2004. Upgrades were done progressively from the late 1980s into the end of the 1990s by FMC.
Upgrades funded by the PIP included: The Up-Gunned Weapon Station (UGWS) designed by Cadillac Gage, featuring a 40 mm Mk 19 Mod 3 automatic grenade launcher alongside a .50 caliber M2 HB machine gun The system retained the improved electrical drive and smoke grenade launchers first installed during the SLEP upgrade The P900 appliqué armor kit (AAK), ordered in 1987 The Enhanced Appliqué Armor Kit (EAAK), produced from 1991 to 1993, provided additional protection against 14.5 mm armor-piercing munitions fired from 300 meters and overhead 155 mm airburst artillery from 30 meters A bow plane to improve handling in water with EAAK equipped Improved radios A magnetic heading system Automatic Fire Sensing and Suppression System (AFSSS) Improved Transmission (I-TRANS) Improved suspension Day/Night Range Sight (DNRS)
The first type of appliqué armor developed was known as P900. In 1987, the Majestic Metal Fabrication Co. was awarded a $2.84 million contract to produce 189 P900 kits for the AAV7A1. This armor consisted of perforated armor plates attached to the hull, improving protection against small arms. It did not see widespread adoption.
The second type of appliqué armor developed became known as the Enhanced Appliqué Armor Kit. Developed by Rafael Armament Development Authority, delivery of 1,137 sets took place from 1991 to 1993. The EAAK added nearly 2 tons to the vehicle, necessitating the installation of a bow plane to maintain the vehicle's handling characteristics in water Unlike P900, EAAK saw widespread adoption and gave the AAV7 its recognizable "corrugated" appearance.
RAM/RS The Assault Amphibious Vehicle Reliability, Availability, Maintainability/Rebuild to Standard (AAV RAM/RS) (or sometimes "Return to Standard") program was initiated in 1997 in order to even further extend the lifespan of the AAV7 family of vehicles and restore the vehicle's performance to its original specifications, offsetting the weight gains and degradations resulting from decades of use. Many of the automotive improvements in the RAM/RS program were sourced from the Bradley Fighting Vehicle, namely the engine and suspension.
The RAM/RS upgrades included: A new Cummins VTA-903T diesel engine developing 525 horsepower Horsepower-to-ton ratio increased to original 17:1 A new HS-525 transmission New "Big Foot" tracks Suspension and running gear from the Bradley Ground clearance restored to 16 inches
The contract for the upgrades was awarded to United Defense (now part of BAE Systems) in 1997. Upgrades began in 1998, with deliveries of 680 vehicles taking place from 1999 through 2004. The program was completed in 2007 after a further 391 vehicles were modified.
C2 Upgrade