Lima Site 85

Coordinates: 20°26′42″N 103°43′05″E / 20.44500°N 103.71806°E / 20.44500; 103.71806
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Lima Site 85
Houaphanh Province, Laos
The LS-85 mountaintop area included radar shelters ("Operations") with antennas and interior equipment normally in/on mobile AN/MSQ-77 "control and plotting" and radar vans. "TACAN" is the box shelter for the AN/TRN-17 electronics with antenna on top, and "LZ" is for the nearby helicopter Landing Zone. Also not shown are the CIA airstrip and command post.
Lima Site 85 is located in Laos
Lima Site 85
Lima Site 85
Coordinates20°26′42″N 103°43′05″E / 20.44500°N 103.71806°E / 20.44500; 103.71806 [1][2]
Site history
Built1967 (1967)

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.

Command post[edit]

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[edit]

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[edit]

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[edit]

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 99 Commando Club missions on NVN required ~500 sorties.[28]


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]

Site defenses and attacks[edit]

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.

See also[edit]


* 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.

  1. ^ Porter. Lima Site 36 (Report). Archived from the original on April 8, 2013. Retrieved 2012-10-24. 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).
  2. ^ a b c d Vallentiny, Capt Edward (9 August 1968). The Fall of Site 85 ( transcription). CHECO Division, Tactical Evaluation Division (HQ PACAF). Archived from the original on 30 January 2013. Retrieved 2012-10-07.
  3. ^ Conboy, Kenneth (199). Shadow War: The CIA's Secret War in Laos. Paladin Press. ISBN 978-1-58160-535-8.
  4. ^ a b c d e Linder, James C. (2004). "The Fall of Lima Site 85". In Dr. Sharad Chauhan (ed.). Inside CIA: Lessons in Intelligence. New Delhi: S.B. Nangia. ISBN 8176486604. Retrieved 2012-10-17. 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
  5. ^ a b c d e Grimes, Richard (2002). "TRN-17 TACAN installation, Lima Site 85, Phou Pha Thi, Laos" (Vietnam War anecdotes). Archived from the original on 2012-07-24. Retrieved 2012-10-07. 3 pages
  6. ^ a b c d e f g h Secord, Maj Gen Richard (1992). "Chapter 6: Disaster at Site 85". Honored and Betrayed (chapter transcription at Air Commando Association webpage). Wiley. ISBN 9780471573289. 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.
  7. ^ Destatte, Robert L (7 April 1998) [translated May 11, 1997]. Raid on the TACAN Site Atop Pha-Thi Mountain by a Military Region Sapper Team on 11 March 1968 ( webpage: "[Source: e-mail Robert J. Destatte to Ron Haden, January 4, 2003]"). Archived from the original on 1 August 2012. Retrieved 2012-11-05. 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:
    • Doox Chis Beenf (1996). "Tran Tap Kich Vao Khu 'TACAN' tren Nui Pa-thi cuar Phan doi Dac Cong Quan Khu, ngay 11 thang 3 nam 1968". Several Battles in Military Region 2 during the War of Liberation, 1945–1975 (in Vietnamese). Hanoi: People's Army Publishing House.
    NOTE: The times translated from the Vietnamese report, e.g., "After only 15 minutes" from "0345" there was "fire directly into the building that had many antennas", are consistently an hour different from the times identified by US records such as Vallentiny and Secord: "At three in the morning, we lost voice and teletype communication with the radar site on the summit" (Secord). Likewise, Sliz identifies he was evacuated at daylight, which the translated Vietnamese report has at "0900 hours".
  8. ^ Castle, Timothy Neil (1993). At War in the Shadow of Vietnam: U.S. Military Aid to the Royal Lao Government, 1955–1975. Columbia University Press. ISBN 978-0-231-07977-8. Retrieved 2012-11-02.
  9. ^ a b c d e f g Plunkett, W. Howard (22 June 2006). "Part II: Combat Lancer and Commando Club". Radar Bombing during Rolling Thunder (2007 ECNext transcription). Retrieved 2012-06-16.
    coms2/summary_0199-5697884_ITM[permanent dead link] (Part I: Ryan's raiders)[permanent dead link]
  10. ^ "6115-00-504-1401 - GENERATOR SET,DIESEL ENGINE,TRAILER MOUNTED - 6115005041401,005041401,MB5,MILG9546,56A56928,M12100". Archived from the original on 2021-12-07. Retrieved 2021-12-07.
  11. ^ Article title
  12. ^ a b "Lima Site 85 Personnel List". Archived from the original on 2011-06-24. Retrieved 2012-10-08.
  13. ^ a b c pp. 70, 100, 160,[full citation needed]
  14. ^ a b c Wolk, Herman S (June 1969). R&D for Southeast Asia, 1965–1967 (PDF). USAF Plans and Policies (Report). Office of Air Force History. Archived from the original (PDF) on 2012-04-23. Retrieved 2012-05-21. 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
  15. ^ a b Wheeler, Gen. Earl G. (25 April 1967). "Installation of MSQ-77 in Northern Laos" (PDF) (CJCS memorandum). Archived from the original (PDF) on 16 September 2012. Retrieved 2012-05-21. cover letter: "radar guidance coverage would be extended over areas of northern NVN and Laos not now covered".
  16. ^ a b "Combat Evaluation Group – A place for CEVG'ers and Range Rats to Meet" (Yahoo newsgroup).[unreliable source]
    a. Jordan, David (August 6, 2004). "TSQ-81" (Google cache of posting 8976). Archived from the original on December 10, 2012. Retrieved 2012-10-09.{{cite web}}: CS1 maint: bot: original URL status unknown (link)
    b. Craft, Eugene Boyd (November 22, 2007). "Last Skyspot academic or practical qualified crews" (…posting 41955). Archived from the original on December 8, 2012. Retrieved 2012-10-08.
  17. ^ Mooney, James L (1976). Dictionary of American Naval Fighting Ships, V. 7: T-V. Government Printing Office. ISBN 978-0-16-002038-4.
  18. ^ a b c Castle, Timothy (1999). One Day Too Long: Top Secret Site 85 and the Bombing of North Vietnam. New York: Columbia University Press. ISBN 0-231-10316-6.
  19. ^ a b c Sliz, Capt Stan. "Captain Stan Sliz was the day shift Controller for Lima Site 85". Archived from the original on 2011-02-20. Retrieved 2012-10-24.
  20. ^ Jeppeson, Chris (April 17, 2003). "Acoubuoy, Spikebuoy, Muscle Shoals and Igloo White: An unofficial history of an electronic warfare operation during Vietnam". Retrieved 2010-08-04. 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 ")
  21. ^ "Construction 7A". Archived from the original on 2012-07-24. Retrieved 2012-11-07.
  22. ^ "5840-00-225-8009 - RADAR BOMB SCORING CENTRAL - 5840002258009,002258009,209000,ANTSQ81". Archived from the original on 2021-12-07. Retrieved 2021-12-07.
  23. ^ "Calfee, James Henry, MSgt". June 1, 2009. Retrieved 2012-10-09.
  24. ^ "AN/- Electronics Equipment, for Shipboard, Submerged or Joint Use". Archived from the original on 2012-10-31. Retrieved 2012-11-12.
  25. ^ a b c d e "34th Tactical Fighter Squadron – Thud Era". Retrieved 2012-10-07. "F-105 History" pages:
    a. "Jacob C. Shuler" (PDF). Retrieved 2012-10-07.
    b. "Donald W. Hodge" (PDF). Retrieved 2012-10-07.
    c. "Joseph S. Sechler" (PDF). Retrieved 2012-10-07.
    d. "David C. Dickson" (PDF). Retrieved 2012-10-31. 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.
  26. ^ "Archived copy" (PDF). Archived from the original (PDF) on 2012-10-07. Retrieved 2012-11-12.{{cite web}}: CS1 maint: archived copy as title (link) "radio relay (WAGER) provides a surveillance/control channel" [pdf p. 695]
  27. ^ a b c d "1968". (transcript of unit history). Archived from the original on 2012-11-08. Retrieved 2012-10-24.
  28. ^ Thompson, Wayne (November 2003). title tbd. Retrieved 2012-11-01. 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.
  29. ^ "Major General John C. Giraudo". United States Air Force. 2012. Archived from the original on 2012-12-12.
  30. ^[permanent dead link]
  31. ^ Webb, Billy G. (2010). Secret War (Scribd ebook). Bloomington: Xlibris Corporation. p. 274. ISBN 978-1-4535-6486-8. LCCN 2010912607. Archived from the original on 2013-12-27. Retrieved 2017-09-09.
  32. ^ "Air Force Sergeant MIA from Vietnam War is Identified" (DoD news release No. 1268-05). Public Affairs (Office of the Assistant Secretary of Defense). 8 December 2005. 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.

External links[edit]

External media
image icon airstrip photographed from summit
image icon TACAN under Chinook
image icon mobile version of AN/TRN-17 with generator trailers
image icon LS-85 map
image icon mountaintop structures
video icon during and after Heavy Green (5:50 shot of both airstrip & mountaintop)