M551 Sheridan AR/AAV

Developed by the United States in 1957, the M551 Sheridan, formally designated the "Armored Reconnaissance/Airborne Assault Vehicle" (AR/AAV), was a light tank fielded by the United States Army in 1967. Named after Civil War General, Philip Sheridan, the M551 was renowned for its unique blend of amphibious capability, air transportability, and advanced weaponry and possessed an unmatched combination of features for its era:

Unparalleled Deployability: The Sheridan boasted exceptional strategic and tactical mobility. It could be airdropped from transport aircraft, thanks to a specially designed air delivery system, and possessed amphibious capabilities for traversing water obstacles. This unique capability made the Sheridan a highly prized asset for rapid deployment scenarios.

Firepower Innovation: The M551 mounted the technically advanced 152mm M81 gun/launcher. This weapon system offered a dual firing capability: conventional artillery rounds for engaging fortified positions and the MGM-51 Shillelagh anti-tank missile, designed to counter the growing threat of Soviet armor. While the Shillelagh missile boasted impressive firepower, it suffered from reliability issues that hampered its effectiveness.

Weight-Saving Design: To meet airdrop weight limitations, the Sheridan’s hull was constructed from lightweight aluminum alloy. This design choice, while enabling air mobility, offered a lower level of ballistic protection compared to contemporary main battle tanks. The turret, however, was constructed from sturdier steel to provide better crew safety.

Developed in the late 1950s and entering service in 1967, the M551 Sheridan saw combat action in the Vietnam War, the Invasion of Panama and the Gulf War. However, the realities of jungle warfare exposed limitations. The aluminum hull proved susceptible to enemy anti-tank weaponry, and the Shillelagh missile system’s shortcomings became readily apparent.

Despite these drawbacks, the M551 remained in service with the 82nd Airborne Division until 1997, valued for its unique airdrop capability. Today, the Sheridan is no longer part of the active US Army inventory. However, it serves as a historical reminder of an ambitious attempt to design a lightweight, rapidly deployable armored vehicle for the Cold War battlefield.

M551 Weapon Systems Designator Codes (WSDC)

• 07A - TANK M551 2410