Lima Site 85
Lima Site 85 (LS-85 alphanumeric code of the phonetic 1st letter used to conceal this covert operation) was a clandestine military installation in the Royal Kingdom of Laos guarded by the Hmong "Secret Army", the Central Intelligence Agency, and the United States Air Force used for Vietnam War covert operations against communist targets in ostensibly neutral Laos under attack by the Vietnam People's Army. Initially created for a CIA command post to support a local stronghold, the site was expanded with a 1966 TACAN area excavated on the mountaintop where a 1967 command guidance radar was  added for Commando Club bombing of northern areas of North Vietnam. The site ended operations with the Battle of Lima Site 85 when most of the U.S. technicians on the mountaintop were killed, including CMSgt Richard Etchberger. For his heroism and sacrifice, Etchberger received the Air Force Cross posthumously. The operation remained classified, however, and the existence of the award was not publicly acknowledged until 1998. After the declassification of LS 85 and a reevaluation of his actions, Etchberger was awarded the Medal of Honor in 2010. Command post. The LS-85 military installation began in August 1966 with TACAN radar  installation at a supply site and command post for "Hmong officers and CIA paramilitary advisers [to control] harassing operations against the Pathet Lao and North Vietnamese". LS-85 was supplied via an "Air America STOL airstrip … two-thirds of the way down the mountain" and the command bunker was down the hill from the summit (identified by the North Vietnamese as the "communications center".) The airstrip was also used for refueling USAF rescue helicopters. TACAN. The tactical air navigation system (TACAN) equipment for Channel 97 at LS-85 was emplaced after Vietnam War Combat Skyspot sites had been created in March 1966  and several TACAN sites, including those at Lima Sites, had similarly been established for military aircraft navigation/guidance. The planned LS-85 TACAN site was surveyed in July 1966 (the Hmong_people flattened the summit and created a helicopter landing zone at lower elevation). The First Mobile Communications Group Team 72-66 deployed the 60 Hz diesel-powered MB5 Generator Set and 1 kilowatt ITT AN/TRN-17 Beacon-Transponder Set from Clark AFB to Udorn RTAFB in August 1966 via a C-123 cargo aircraft—then to the Sam Thong runway (LS-20) for transfer to Army CH-47 Chinooks which refueled later at Nakhang  (LS-36) to complete the airlift to LS-85. The LS-85 TACAN area with the AN/TRN-17, generator, diesel supply, and "Comm and Relay Center" was operating on September 24, 1966; and the portion of LS-85 serviced by the landing zone was supported (supplies, etc.) by Continental Air Services using PONY EXPRESS Sikorsky CH-3 helicopters (the USAF museum displays one used for LS-85.) Fuel drums for the MB5 were landed directly at the mountaintop. Combat Target. Combat Target was a March 1967 task force that recommended a Combat Skyspot site closer to Hanoi for more accurate bombing at night and during poor  weather (endorsed by General Earle G. Wheeler on April 25, 1967.) In April 1967, Reeves Instrument Corporation was contracted to modify the trailer-mobile ("M") AN/MSQ-77 design to a helicopter transportable ("T") version without trailer chassis/wheels and other mobility equipment. The initial variant (AN/TSQ-81) was tested at Bryan Field, Texas, using bomb runs over Matagorda Island General Bombing and Gunnery Range and was emplaced for Combat Skyspot in Thailand. After Bryan/Matagorda testing of the 2nd AN/TSQ-81, it was operational at LS-85 in late 1967, the period when the ""1st CEVG began "Combat Keel" tests using  F-4s guided by an AN/MSQ-77 on the "USS "Thomas J. Gary" in the Gulf of Tonkin to test command guidance by ships against northern targets ("Gary" after beginning by August 9, departed by December 12). Heavy Green. Heavy Green was the military operation to emplace a Reeves AN/TSQ-81 Bomb Directing Central on the LS-85 summit adjacent to the TACAN area particularly for monsoon season bombing of northern North Vietnam. The site's Initial inspection regarding suitability for ground-directed bombing was by its eventual 7th AF coordinator, and geodetic surveying was by a 1st Combat Evaluation Group team  manned from existing Combat Skyspot operating locations. The site was developed under USAF Major Richard Secord (assisted by Tom Clines) by first "clearing additional space on the white karst limestone mountaintop" with blasting by a "Navy Seabee demolitions expert". Construction included leveling steel girders on vertical posts to allow a Corps of Engineers CH-47s to airlift the "new equipment, vans [rigid shelters], and prefab crew quarters". Defenses included a defensive bunker and an inner perimeter with outpost, and a frequency converter shelter provided the 3 phase 400 Hz power needed for precision pointing by the radar's antenna motors. The  camouflaged Cassegrain antenna was on the roof of the operations shelter, while the connected shelter had a rotating identification friend or foe antenna and mast antennas for UHF and VHF communications. A calibration in September 1967 included an estimation of the AN/TSQ-81 antenna coordinates by "fly-in" using aircraft tracked by LS-85 while overflying previously-surveyed nearby peaks (surveyors at the peaks observed the flyover precision).