Lima Site 85: How a CIA Helicopter Defended a Secret U.S. Radar Facility

Summary

In the history of covert military operations, few incidents match the audacity and engineering of the shootdown of a modified North Vietnamese An-2 transport plane converted to a bomber by a CIA-operated helicopter in Laos. This event occurred during the Vietnam War, a conflict marked by unconventional warfare and daring missions.The stage for this incident was Lima Site 85, a secret United States Air Force radar installation located atop Phou Pha Thi, a remote mountain in northeastern Laos.Established in 1966, Lima Site 85 was crucial for guiding bombing missions over North Vietnam. Operated in secrecy and defended by CIA-backed forces, including Hmong irregular troops, the site’s existence was shrouded in layers of secrecy.Lima Site 85 played a key role in the U.S. bombing campaign against North Vietnam due to its strategic location and advanced radar technology. The installation featured the AN/TSQ-81 radar system, part of the innovative Commando Club program.This radar enabled precision-guided bombing in all weather conditions, a critical capability in a conflict where poor visibility often hindered air operations. By directing attacks, the radar significantly increased the effectiveness of U.S. bombing campaigns against key North Vietnamese targets.In addition to the AN/TSQ-81, the site employed a tactical air navigation (TACAN) system, providing navigation assistance to combat aircraft operating in the region. The combination of these technologies made Lima Site 85 indispensable to U.S. military operations, rendering it one of the most valuable and vulnerable facilities in the theater of war.The attackOn a tense morning in early 1968, a North Vietnamese Army (NVA) An-2 approached Lima Site 85, aiming to disrupt operations and test the defenses of the highly classified installation. The An-2, a tactical transport biplane, was modified to deliver munitions and supplies through floor openings in its cabin, making it a versatile tool for the NVA.It was armed with ...