Lima Site 85 | |
---|---|
Houaphanh Province, Laos | |
Coordinates | 20°26′42″N103°43′05″E / 20.44500°N 103.71806°E [1] [2] |
Site history | |
Built | 1967 |
Demolished | 1968 |
Lima Site 85 (LS-85 alphanumeric code of the phonetic 1st letter used to conceal this covert operation [3] ) 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.
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". [4] LS-85 was supplied via an "Air America STOL airstrip [5] … two-thirds of the way down the mountain" [6] and the command bunker was down the hill from the summit [2] (identified by the North Vietnamese as the "communications center".) [7] The airstrip was also used for refueling USAF rescue helicopters. [8]
The tactical air navigation system (TACAN) equipment for Channel 97 [9] 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. [5] : 1 The planned LS-85 TACAN site was surveyed in July 1966 (the Hmong flattened the summit and created a helicopter landing zone at lower elevation). [5] : 4 The First Mobile Communications Group Team 72-66 deployed the 60 Hz diesel-powered [10] MB5 Generator Set and 1 kilowatt [11] 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. [5]
The LS-85 TACAN area with the AN/TRN-17, generator, diesel supply, and "Comm and Relay Center" [12] was operating on September 24, 1966; [9] and the portion of LS-85 serviced by the landing zone was supported (supplies, etc.) by Continental Air Services [13] : 70 using PONY EXPRESS Sikorsky CH-3 helicopters (the USAF museum displays one used for LS-85.) [13] : 160 Fuel drums for the MB5 were landed directly at the mountaintop.
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 [14] : 68 (endorsed by General Earle G. Wheeler on April 25, 1967.) [15] 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, [5] : 4 using bomb runs over Matagorda Island General Bombing and Gunnery Range and was emplaced for Combat Skyspot in Thailand. [16] 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 [14] : 68 (Gary after beginning by August 9, departed by December 12). [17]
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, [18] : 36 and geodetic surveying [13] : 100 was by a 1st Combat Evaluation Group team manned from existing Combat Skyspot operating locations. [12] The site was developed under USAF Major Richard Secord (assisted by [ specify ]Tom Clines) by first "clearing additional space on the white karst limestone mountaintop" [6] with blasting by a "Navy Seabee demolitions expert". [18] : 36 Construction included leveling steel girders on vertical posts to allow a Corps of Engineers [19] CH-47s to airlift [20] the "new equipment, vans [rigid shelters], and prefab crew quarters". [6] Defenses included a defensive bunker and an inner perimeter with outpost, [19] 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 [21] included an estimation of the AN/TSQ-81 [22] 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). [16]
Commando Club was a US operation of the Vietnam War that used command guidance of aircraft by the Laos Site 85 radar for ground-directed bombing (GDB) of targets in North Vietnam and clandestine targets in Laos. The Detachment 1, 1043rd Radar Evaluation Squadron, technicians and officers at LS-85 [23] performed radar/computer/communications operations with the Reeves AN/TSQ-81 Bomb Directing Central as Lockheed civilians (volunteers discharged from the USAF for cover). The Combat Skyspot site [19] used typical GDB procedures for Commando Club, including planning missions, providing coordinates to LS-85 and bomber crews, handoff of the bomber from air controllers to LS-85, tracking the aircraft by radiating the bomber's 400 Watt transponder, [24] and radioing of technical data from the bomber such as the airspeed to LS-85 for the AN/TSQ-81 to estimate wind speed on the bomb(s). Due to limited reliability of the LS-85 radios (callsign "Wager Control" [9] at 396.2 MHz), [25] : a an intermediary aircraft (EC-121 [25] : b or "usually a C-135…decoy ship") [6] provided a "radio relay [and] surveillance/control channel" (callsign: WAGER) between LS-85 and the bomber. [26]
With the bomber near a designated "Initial Point" LS-85 would begin a radar track and the Bomb Directing Central's analog computer would calculate a computer track and solve the "bomb problem" for the aircraft's flight path. The central then automatically transmitted guidance commands to the aircraft (lead aircraft for multi-ship formations, e.g., 3 Boeing B-52 Stratofortresses) to adjust the bomb run toward an eventual release point for the actual bomb(s). The central at LS-85 automatically effected release of the ordnance from the aircraft to eliminate the variable crewmember delay during the greater vulnerability of the generally steady bomb run.
Commando Club/total missions by target area & period [2] | |||
Period | North Vietnam [ verification needed ] | Barrel Roll "around" LS-85 [27] | Both areas |
November | 20/153 (13%) | 1/268 | 21/421 (5%) |
December | 20/94 (21%) | 67/327 (20%) | 87/421 (21%) |
January | 29/125 (55%) | 23/320 (10%) | 52/445 (12%) |
February | 27/49 (55%) | 142/375 (38%) | 169/424 (40%) |
March 1–10 | 3/6 (50%) | 165/182 (91%) | 168/188 (89%) |
Total | 99*/427 (20%) | 398/1472 [27] (27%) | 497/1899 (26%) |
The LS-85 radar using day/night shift crews of 5 men each [4] became operational on November 1, 1967; [14] and trial missions[ clarification needed ] of Commando Club by Republic F-105 Thunderchiefs were led[ specify ] by Col. John C. Giraudo [9] (355th Fighter Wing commander). [29] F-105 Commando Club missions included the November 15, 1967, 357th Tactical Fighter Squadron bombing of Yên Bái Air Base in Route Package 5 ("no BDA possible") and the defeated November 18 raid of 16 F-105s of the 388th Tactical Fighter Wing—preceded by 4 F-105 Wild Weasels—on Phúc Yên Air Base (JCS Target 6). [9] The latter mission's loss of 2 Wild Weasels to MiGs and then some of the bombers to SAM sites that tracked the USAF jamming resulted in temporary suspension of Commando Club until electronic countermeasures were improved. Through November 16, LS-85 had effected a direct hit (zero miss distance) as well as a 5 mi (8.0 km) miss: the Commando Club CEP for "14 runs was 867 feet" [9] while other Skyspot sites for 1967 missions averaged 300–350 ft (91–107 m) error at ranges ≤100 nmi (190 km; 120 mi). [15] LS-85 accuracy was improved during the suspension period, another UHF radio was added at the summit, and the radio relay's secondary task of surveilling for MiGs was eliminated. [30]
Commando Club was resumed by November 21 when F-105s attacked the Yên Bái airfield (also on December 1 & 23, [9] January 5, & February 11.) [25] : d LS-85 directing bombings of Laos' Ban Phougnong truck park on December 22, a target "25 miles west of Channel 97" on December 28, and "a target 20 miles east of San Neua" December 31; and "Commando Club under Wager Control" bombed the Kim Lo Army Barracks northwest of Hanoi on February 7, 1968, [25] : c a Route Pack V target on February 11, and the "Phuc Yen (JCS 6) airfield" & "the Ban Nakay truck park in Northern Laos" on February 19. [25] : d Arc Light B-52s and other aircraft also flew missions of Commando Club, which were 20% (less than 1 per day) of all bombing missions on North Vietnam targets during November 1 – March 10. Commando Club airstrikes against Laos targets included operations to interdict enemy advances on LS-85 such as the Battle of Route 602. "On 21 February the Ambassador authorized the Local Area Defense Commander (alternately the senior CIA officer or the FAC) to use the TSQ radar to direct any and all strikes within 12 kilometers of the summit" and "between the 20th and 29th, 342 sorties hit within 30 kilometers of Phou Phathi." [2] Commando Club operations against Route 602 and advancing troops were part of the approximately 400 Commando Club missions out of the "1,472 BARREL ROLL Strike missions" flown "around" LS-85 from November 1 – March 10. [27] When the enemy reached positions near the site, the order from Washington, D.C., was to "hold the site at all costs." [6]
The initial assessment by the site's 7th AF coordinator was that after radar operations began LS-85 would be attacked within 6 months, [18] : 35 which a February 25 CIA report accurately predicted would be after March 10. Summit structures at LS-85 had originally been outfitted with demolition charges (later removed by the technicians), and the personnel eventually had small arms (e.g., M16 rifles) for defense. [4] TACAN and AN/TSQ-81 personnel were included in the February plan [4] to evacuate when the site's risk became too high, and defense training had been provided. An enemy patrol was dispersed from the base of the mountain on January 10, [6] a January 12 airstrike bombed LS-85, [31] [ self-published source ] and a mortar attack was on January 30. On February 18 near the head of the road an NVA survey party was defeated (the NVA map with planned artillery positions was captured.) [6] On March 10 (1800–1945 hours), an "artillery barrage" preceded an attack toward the southeast slope by 3 battalions [4] ("a kilometer or two from the hill"), [6] and commandos including Hmong defectors—instead of assaulting in a direct infantry attack upslope toward the radar station—scaled the north mountain cliff and after midnight killed the majority of the onsite technicians. [27] All areas of LS-85 were captured, and the remaining mountaintop structures were destroyed by US airstrikes through the next week. A Top Secret August 1968 US official history was declassified in 1988, and a 1996 North Vietnamese Report was translated in 1998. Post-war visits to the site resulted in identification of US radar crewmembers remains in 2005 [32] and 2012.
During Operation Arc Light from 1965 to 1973, the United States Air Force deployed B-52 Stratofortresses from bases in the U.S. Territory of Guam to provide battlefield air interdiction during the Vietnam War. This included strikes at enemy bases, supply routes, and behind the lines troop concentrations, as well as occasionally providing close air support directly to ground combat operations in Vietnam.
Operation Commando Hunt was a covert U.S. Seventh Air Force and U.S. Navy Task Force 77 aerial interdiction campaign that took place during the Vietnam War. The operation began on 15 November 1968 and ended on 29 March 1972. The objective of the campaign was to prevent the transit of People's Army of Vietnam (PAVN) personnel and supplies on the logistical corridor known as the Ho Chi Minh Trail that ran from southwestern North Vietnam through the southeastern portion of the Kingdom of Laos and into South Vietnam.
Ground-directed bombing (GDB) is a military tactic for airstrikes by ground-attack aircraft, strategic bombers, and other equipped air vehicles under command guidance from aviation ground support equipment and/or ground personnel. Often used in poor weather and at night, the tactic was superseded by an airborne computer predicting unguided bomb impact from data provided by precision avionics Equipment for radar GDB generally included a combination ground radar/computer/communication system and aircraft avionics for processing radioed commands.
The Battle of Lima Site 85, also called Battle of Phou Pha Thi, was fought as part of a military campaign waged during the Vietnam War and Laotian Civil War by the North Vietnamese People's Army of Vietnam (PAVN) and the Pathet Lao, against airmen of the United States Air Force (USAF)'s 1st Combat Evaluation Group, elements of the Royal Lao Army, Royal Thai Border Patrol Police, and the CIA-led Hmong Clandestine Army. The battle was fought on Phou Pha Thi mountain in Houaphanh Province, Laos, on 10 March 1968, and derives its name from the mountaintop where it was fought or from the designation of a 700-foot (210 m) landing strip in the valley below, and was the largest single ground combat loss of United States Air Force members during the Vietnam War.
Operation Barrel Roll was a covert U.S. Air Force 2nd Air Division and U.S. Navy Task Force 77, interdiction and close air support campaign conducted in the Kingdom of Laos between 14 December 1964 and 29 March 1973 concurrent with the Vietnam War. The operation resulted in 260 million bombs being dropped on Laos.
Operation Niagara was a U.S. Seventh Air Force close air support campaign carried out from January through March 1968, during the Vietnam War. Its purpose was to serve as an aerial umbrella for the defense of the U.S. Marine Corps Khe Sanh Combat Base on the Khe Sanh Plateau, in western Quang Tri Province of the Republic of Vietnam. The base was under siege by an estimated three-divisional force of the People's Army of Vietnam (PAVN).
The 1st Combat Evaluation Group was a Strategic Air Command (SAC) unit. It was formed on 1 August 1961 to merge the 3908th Strategic Standardization Group for SAC aircrew evaluation with the 1st Radar Bomb Scoring Group that had originated from the 263rd Army Air Force Base Unit which transferred from 15th AF to directly under Strategic Air Command c. 1946. The 1CEVG formed after SAC switched to low-level tactics to counter Soviet surface-to-air missiles and SAC had "developed a Radar Bomb Scoring field kit for use in NIKE Systems" in early 1960 for scoring SAC training missions against US Hercules SAM sites. The 1CEVG headquarters included an Office of History and a "standardization and evaluation school" for command examiners.
Operation Pony Express was the covert transportation of, and the provision of aerial support for, indigenous soldiers and material operating across the Laotian and North Vietnamese borders during the Vietnam War. It was provided by Sikorsky CH-3C helicopters of the US 20th Helicopter Squadron, the only USAF combat helicopter squadron in Vietnam, which had been transferred there in 1965 and was known as the "Pony Express".
The Raven Forward Air Controllers, also known as The Ravens, were fighter pilots used as forward air controllers (FACs) in a covert operation in conjunction with the US Central Intelligence Agency in Laos during America's Vietnam War. The Ravens pinpointed targets for most of the air strikes against communist Pathet Lao and People's Army of Vietnam infiltrators in support of the Laotian Hmong guerrilla army.
Forward air controllers (FACs) played a significant part in the Vietnam War from the very start. Largely relegated to airborne duty by the constraints of jungled terrain, FACs began operations as early as 1962. Using makeshift propeller-driven aircraft and inadequate radio nets, they became so essential to air operations that the overall need for FACs would not be completely satisfied until 1969. The FAC's expertise as an air strike controller also made him an intelligence source, munitions expert, communication specialist, and above all, the on-scene commander of the strike forces and the start of any subsequent combat search and rescue if necessary.
The Vietnam People's Air Force, officially the Air Defence - Air Force Service or the Vietnam Air Force, is the aerial and space service branch of Vietnam. It is the successor of the former North Vietnamese Air Force (NVAF) and absorbed the South Vietnamese Air Force (RVNAF/VNAF) following the reunification of Vietnam in 1975 and is one of three main branches of the People's Army of Vietnam, which is under the control of the Ministry of National Defence. The main mission of the VPAF is the defence of Vietnamese aerospace and the provision of air and space cover for operations of the People's Army of Vietnam.
The Reeves AN/MSQ-77 Bomb Directing Central, Radar was a United States Air Force automatic tracking radar/computer system for command guidance of aircraft. It was often used during Vietnam War bomb runs at nighttime and during bad weather. Developed from the Reeves AN/MSQ-35, the AN/MSQ-77 reversed the process of Radar Bomb Scoring by continually estimating the bomb impact point before bomb release with a vacuum tube ballistic computer. Unlike "Course Directing Centrals" which guided aircraft to a predetermined release point, the AN/MSQ-77 algorithm continuously predicted bomb impact points during the radar track while the AN/MSQ-77's control commands adjusted the aircraft course. A close air support regulation prohibited AN/MSQ-77 Combat Skyspot bombing within 1,000 yd (910 m) of friendly forces unless authorized by a Forward Air Controller, and "on several occasions" strikes were as close as 273 yd (250 m).
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Phou Pha Thi (Phathi) is a "sacred mountain" in Laos "believed...inhabited by great "phi", or spirits and used for the clandestine Lima Site 85 military installation during the Vietnam War. The lightly defended installation was destroyed by North Vietnamese attackers in the 10-11 March 1968 Battle of Lima Site 85. From 1994 to 2004, searches for USAF remains were conducted at the mountain, but few bodies were located. The mountain is "100 miles south of Dien Bien Phu, 160 miles west of Hanoi, and just 25 miles from the capital of Samneua". The site had been used as a military site by French colonialists until seized by the North Vietnamese in 1962, and the Hmong "Secret Army" recaptured the area and a Central Intelligence Agency airstrip was built by 1966.
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Reeves Instrument Corporation (RICO) was a Cold War manufacturer of computer and radar systems for the United States. The corporation was the Project Cyclone laboratory operator for simulation of guided missiles, and RICO developed several Strategic Air Command combination (radar/computer/communications) systems.
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Lima Site 36 was an Air America and U.S. Air Force facility built in the village of Na Khang, near the Plain of Jars in Laos, during the Vietnam War. It was the scene of several clashes in 1966, 1967 and 1968 and was finally captured by the People's Army of Vietnam forces in 1969.
The Vinh wiretap was an American espionage operation of the Vietnam War. From 7 December 1972 through early May 1973, CIA telephone intercepts of North Vietnamese military communications were supplied to American diplomat Henry Kissinger. As border phone lines were well watched, the decision was made to tap a military multiplex line in the Vietnamese heartland near Vinh. The CIA used a black helicopter to set a clandestine wiretap to eavesdrop on Paris Peace Talks discussions and other intelligence.
* The May 11, 1997, DoD translation of Do Chi Ben's Tran Tap Kich Vao Khu 'TACAN' tren Nui Pa-thi cuar Phan doi Dac Cong Quan Khu, ngay 11 thang 3 nam 1968 by Robert J. Destatte (translation edited April 7, 1998) is entitled Raid on the TACAN Site Atop Pha-Thi Mountain by a Military Region Sapper Team on 11 March 1968.
In late December 1966 and early January 1967, the North Vietnamese troop buildup in the Sam Neue area (VH 0157) had been observed as a potential threat to Lima Site 36 (UH 4113), Lima Site 52 (VH 0581), and Lima Site 85 (UH 6860).
Site 85 command post, a ramshackle structure next to the helicopter landing area … helipad, a 20-minute walk down the ridge from the radar vans on the peak
We already had a 600-foot STOL strip three-quarters of the way up the mountain for resupplying local Meo guerrilla … One wounded and extraordinarily unlucky technician was killed, shot through the back during helicopter evacuation.
At 0900 hours, one helicopter dropped a line down near the TACAN site and rescued three wounded enemy. We were tangled up in the mountain, so we fired on it without hitting it.translation of:
On 1 November 1967, another MSQ-77[ sic ] became operational in Laos(p. 58: Wolk cites "DJSM-800-68 (TS ), Memo for DDR&E, CSAF, CNO, et al, 28 June 68, subj: Update of the NIGHT SONG Study ".) Archived 2012-10-07 at the Wayback Machine
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: CS1 maint: bot: original URL status unknown (link)air-lifted by CH-47 helicopter to the ridge of a 5,580-ft. mountain called Phou-Pa-Thi…where a TACAN navigation site was already located( NOTE: This webpage included an image with filename "BROMO.jpg" and "alt="BROMO TSQ-96 inside INVERT, NKP ")
34 TFS were diverted to a target in Laos as a result of the North Vietnamese attack on Lima Site 85. They took off at 0715 and returned after 2 hours 55 minutes. … "We were diverted up to Lima 85 up by the North TACAN station. The bad guys were trying to storm the hill. The hill was sticking up through the clouds but we couldn't detect any enemy action. The A-1Es were working over the enemy but they wouldn't let us in on the action. Instead they put us in on an enemy gun emplacement about 10 miles away.
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: CS1 maint: archived copy as title (link) "radio relay (WAGER) provides a surveillance/control channel" [pdf p. 695]From November 1967 to March 1968, controllers at Phou Pha Thi directed nearly a hundred "Commando Club" missions (about five hundred sorties) against the Red River Delta.
Shannon and 18 other servicemen operated a radar installation atop Pha Thi Mountain in Houaphan Province, Laos, approximately 13 miles south of the border with North Vietnam. … In 2002, one of the enemy soldiers stated that he helped throw the bodies of the Americans off the mountain after the attack, … Between 1994 and 2004, 11 investigations were conducted by both JPAC as well as unilaterally by Lao and Vietnamese investigators on both sides of the border. During one of the investigations, several mountaineer-qualified JPAC specialists scaled down the cliffs where they recovered remains and personal gear on ledges. JPAC and Armed Forces DNA Identification Laboratory scientists used mitochondrial DNA and other forensic techniques to identify the remains as those of Shannon.