The Battle of Lima Site 85 was fought between a combined force of US troops and Laos Army elements and the North Vietnamese Army 766th Regiment, from March 10 to March 11, 1968, during the Vietnam War. It took place in Phou Pha Thi, northeastern Laos. Lima Site 85 was a US helicopter landing site which had been established in 1966 on the peak of Phou Pha Thi mountain, Laos, by the US Air Force to assist ongoing aerial operations against the North Vietnamese Army, which used Laos as a sanctuary plataform from which they launched military operations against the South Vietnamese Army. The term "Lima Site" was derived from the American acronym for map designations of "Landing Sites" within the Secret War zone of the Vietnam War, an active covert battleground in the larger Cold War.
On January 12, 1968, 4 Vietnam People’s Air Force Antonov An-2 biplanes had attempted to destroy the base. The Antonov An-2 planes had reached LS 85 and begun dropping 120 mm mortar rounds on the site and making strafing runs. The battle of Lima Site 85 was initiated on the night of March 10, 1968, when the North Vietnamese Army 766th Regiment launched a diversionary attack, preceded by an artillery barrage, against the US landing base.
During the night, the North Vietnamese sappers stealthily climbed the 5,600-foot mountain, while other communist infantry units fought their way up the slopes to create a diversion. The Americans were taken by surprise when 40 North Vietnamese sappers appeared with submachine guns and RPG-7s, attacking Lima Site 85 from the rear. Several US servicemen were killed in the vicious battle that ensued. Throughout the night, US F-4 Phantom fighter-bombers and A-26 bombers repeatedly hit the attackers, while simultaneously, Air America aircraft were ready to evacuate the survivors. By morning, USAF and Air America missions had airlifted out the remaining defenders, including five American survivors and the wounded personnel.
