Assault Amphibious Vehicle

A pair of U.S. Marine Corps Assault Amphibious Vehicles emerge from the surf onto the sand of Freshwater Beach, Australia. The one on the left has an applique armor kit installed, the one on the right does not.

Marines exit from a U.S. Assault Amphibious Vehicle during a live-fire exercise in Djibouti, Africa, in 2010

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 Marine Corps selected a proposal by FMC. FMC delivered the first of 15 prototypes, designated LVTPX12, in October 1967. Marine Corps testing concluded in September 1969. In June 1970, the Marine Corps awarded FMC a $78.5 million contract for the production of 942 vehicles.[6][7]

The LVTP-7 was first introduced in 1972. In 1982, FMC was contracted to conduct the LVTP-7 Service Life Extension Program (SLEP), which converted the LVT-7 vehicles to the improved AAV-7A1 vehicle by adding an improved engine, transmission, and weapons system and improving the overall maintainability of the vehicle. The Cummins VT400 diesel engine replaced the GM 8V53T, and this was driven through FMC's HS-400-3A1 transmission. The hydraulic traverse and elevation of the weapon station was replaced by electric motors, which eliminated the danger from hydraulic fluid fires. The suspension and shock absorbers were strengthened as well. The fuel tank was made safer, and a fuel-burning smoke generator system was added. Eight smoke grenade launchers were also placed around the armament station. The headlight clusters were housed in a square recess instead of the earlier round type. The driver was provided with an improved instrument panel and a night vision device, and a new ventilation system was installed. These upgraded vehicles were originally called LVT-7A1, but the Marine Corps renamed the LVTP-7A1 to AAV-7A1 in 1984.

Another improvement was added starting in 1987 in the form of a Cadillac Gage weapon station or Up-Gunned Weapon Station (UGWS) which was armed with both a .50 cal (12.7 mm) M2HB machine gun and a Mk-19 40 mm grenade launcher.

Enhanced Applique Armor Kits (EAAK) were developed for the AAV-7A1 in 1989 and fitted by 1993, and the added weight of the new armor necessitated the addition of a bow plane kit when operating afloat.

The Assault Amphibious Vehicle Reliability, Availability, Maintainability/Rebuild to Standard (AAV RAM/RS) Program was approved in 1997. It encompassed all AAV systems and components to return the AAV to the original vehicle's performance specifications and ensure acceptable readiness until the EFV should become operational. The program replaced both the AAV engine and suspension with US Army M2 Bradley Fighting Vehicle (BFV) components modified for the AAV. Ground clearance returned to 16 inches (40.6 cm) and the horsepower to ton ratio increased from 13 to 1 to its original 17 to 1. The introduction of the BFV components and the rebuild to standard effort was expected to reduce maintenance costs for the expected remaining life of the AAV through the year 2013.

In March 2015, SAIC was awarded a contract to perform an AAV Survivability Upgrade (SU).[8] Marine Corps and SAIC officials unveiled the AAV SU prototype in January 2016, with survivability enhancements including replacing the angled EAAK with 49 advanced buoyant ceramic armor panels, a bonded spall liner, armor-protected external fuel tanks, an aluminum armor underbelly providing Mine Resistant Ambush Protected (MRAP)-equivalent blast protection, and blast mitigating seats as well as a more powerful engine, new suspension system, and increased reserve buoyancy.[9][10][11] The AAV SU program was intended to upgrade 392 out of the some 1,000-vehicle fleet to keep them operational through 2035 as the ACV gradually entered service. However, in August 2018 the Marine Corps terminated the AAV upgrade program, instead opting for increased procurement of the ACV.[12][13]

An US Marine Corps AAV during the First Battle of Fallujah, April 2004

Twenty U.S.-built LVTP-7s were used by Argentina during the 1982 invasion of the Falkland Islands[14] with most returning to the Argentine mainland before the war ended.

From 1982 to 1984, LVTP-7s were deployed with U.S. Marines as part of the multi-national peacekeeping force in Beirut, Lebanon. As Marines became increasingly involved in hostilities, several vehicles sustained minor damage from shrapnel and small arms fire.

On October 25, 1983 U.S. Marine LVTP-7s conducted a highly successful amphibious landing on the island of Grenada as part of Operation Urgent Fury.

It was heavily used in the 1991 Gulf War and Operation Restore Hope.

After the 2003 invasion of Iraq, AAV-7A1s were criticized for providing poor protection for the crew and passengers compared with other vehicles, such as the M2 Bradley. Eight were disabled or destroyed during the Battle of Nasiriyah, where they faced RPG, mortar, tank and artillery fire. At least one vehicle was destroyed by fire from friendly A-10 Warthog aircraft.[15][16][17]

On 3 August 2005, 14 U.S. Marines and their Iraqi interpreter were killed when their AAV struck a roadside bomb in the city of Haditha in the Euphrates river valley in western Iraq.[9][18]

During the 2010 Rio de Janeiro security crisis, the Brazilian Naval Fusiliers used AAV-7A1s in support of their operations to occupy the Complexo da Penha and Complexo do Alemão favelas, where the vehicles were used to clear barricades left by the Red Command.[19][20]

Eight U.S. Marines and one U.S. Navy sailor died on 30 July 2020, when their AAV sank in the Pacific Ocean off the coast of San Clemente Island, California, during a training exercise, ahead of an upcoming deployment.[21] As a result of the incident, on 15 December 2021 the U.S. Marine Corps announced that it has banned its fleet of amphibious armored personnel carriers from maritime operations except in emergencies.[22]

Renamed from the Advanced Assault Amphibious Vehicle in late 2003, the Expeditionary Fighting Vehicle (EFV) was designed to replace the aging AAV. Able to transport a full Marine rifle squad to shore from an amphibious assault ship beyond the horizon with three times the speed in water and about twice the armor of the AAV, and superior firepower as well it was the Marine Corps' number one priority ground weapon system acquisition. The EFV was intended for deployment in 2015.[23] However, in January 2011, United States Defense Secretary Robert Gates announced plans to cancel the Expeditionary Fighting Vehicle. In 2012, the USMC dropped the EFV and cancelled the program.

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.[24][25]