Hughes OH-6 Cayuse

{{Short description|1963 scout helicopter}} {{Use mdy dates|date=May 2026}} {{Infobox aircraft |name= OH-6 Cayuse |image= File:2019 Royal International Air Tattoo EGVA - Hughes OH-6A Cayuse - G-OHGA 69-16011 (48372649516).jpg |caption= OH-6A Cayuse at RIAT 2019 |type= Light Observation Helicopter/utility |national_origin= United States |manufacturer= Hughes Helicopters McDonnell Douglas Helicopter Systems MD Helicopters |designer= |first_flight= February 27, 1963 |introduction= 1966 |retired= |status= In service |primary_user= United States Army |more_users= |produced= 1965–present |number_built= 1,420 (OH-6A)<ref name="Francillon_248">Francillon 1990, p. 248.</ref> |variants= MD Helicopters MH-6 Little Bird MD Helicopters MD 500 McDonnell Douglas MD 500 Defender }}

The '''Hughes OH-6 Cayuse''' is a single-engine light helicopter designed and produced by the American aerospace company Hughes Helicopters. Its formal name is derived from the Cayuse people, while its "'''Loach'''" nickname is derived from the Light Observation Helicopter (LOH) program, under which it was procured.

The OH-6 was developed to meet United States Army Technical Specification 153, issued in 1960 to replace its Bell H-13 Sioux fleet. The Model 369 submitted by Hughes competed against two other finalists, Fairchild-Hiller and Bell, for a production contract. On February 27, 1963, the first prototype conducted its maiden flight. The Model 369 had a distinctive teardrop-shaped fuselage that was crashworthy and provided excellent external visibility. Its four-bladed full-articulated main rotor made it particularly agile, and it was suitable for personnel transport, escort and attack missions, and observation. During May 1965, the U.S. Army awarded a production contract to Hughes.

During 1966, the OH-6 began service with the U.S. Army, and promptly entered active combat in the Vietnam War. In theater, it was commonly operated in teams with rotorcraft such as the Bell AH-1 Cobra attack helicopter, using so-called "hunter-killer" tactics to flush out and eliminate hostile ground targets. The OH-6 would act as bait to draw enemy fire and mark targets for other platforms such as the AH-1 to attack. In one clandestine incident in 1972, known as the Vinh wiretap, a pair of OH-6As were heavily modified and used by the Central Intelligence Agency (CIA) via Air America to infiltrate Vietnamese high level communications, providing valuable intelligence. Reportedly, 964 out of the 1,422 OH-6As produced for the U.S. Army were destroyed in Vietnam alone.{{Citation needed |date=April 2023}}

During 1967, following price escalations for the OH-6, the U.S. Army reopened the program to bids for as many as 2,700 additional airframes beyond the 1,300 OH-6s already contracted. Following a competitive fly-off and a sealed bidding process, Hughes lost the contract to Bell, resulting in the competing Bell OH-58 Kiowa being produced. The OH-6/Model 369 was license-produced overseas by the Japanese aerospace company Kawasaki Heavy Industries for both military and civilian operators. It was also developed into a civilian helicopter, the Model 500, produced into the 21st century by MD Helicopters as the ''MD 500''.{{Citation needed |date=April 2023}}

==Development== ===Background=== thumb|YOH-6A prototype During 1960, the United States Army issued Technical Specification 153 for a ''Light Observation Helicopter'' (LOH) capable of fulfilling various roles on the battlefield, including personnel transport, escort, casualty evacuation, observation, and attack missions. These would be used to replace its fleet of Bell H-13 Sioux, a compact first generation rotorcraft.<ref name = "McGowen 105"/> Twelve companies opted to participate in the competition, Hughes Tool Company's Aircraft Division being one of them, submitted the ''Model 369'' as its response. Two of these designs, those submitted by Fairchild-Hiller and Bell, were selected as finalists by the Army-Navy design competition board. However, the U.S. Army subsequently chose to include Hughes's Model 369 for further consideration as well.

In terms of its basic configuration, the Model 369 had an atypical teardrop-shaped fuselage, a feature that led to personnel sometimes referring to it as the "flying egg".<ref name = "McGowen 105"/> This shaping, combined with the provision of internal bulkheads, has been attributed as giving the rotorcraft its uncommonly strong crashworthiness properties. This aspect was further bolstered by the use of self-sealing fuel tanks that lowered the likelihood of a post-impact fire breaking out.<ref name = "McGowen 105"/> The pilot was provisioned with excellent external visibility via its large plexiglass windscreen, while its four-bladed fully-articulated main rotor meant it was considerably more agile than the preceding H-13 Sioux. It would often be crewed by a pilot and an observer; up to five passengers or up to 1,000lb of cargo could be carried internally.<ref name = "McGowen 106"/>

===Into flight=== On February 27, 1963, the first Model 369 prototype performed its maiden flight.<ref name = "McGowen 105">McGowen 2005, p. 105.</ref> Originally designated as the ''YHO-6A'' according to the Army's designation system, the aircraft was redesignated as the ''YOH-6A'' in 1962 when the Department of Defense created a joint designation system for all aircraft. A total of five prototypes were built, all of which were powered by a single Allison T63-A-5A turboshaft engine, capable of producing {{convert|252|shp|abbr=on}}.<ref>{{cite web |url=http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/0/5a2fac771f141cfc8625836900554c3e/$FILE/H3WE_Rev_27.pdf |title=Type Certification Data Sheet NO. H3WE |publisher=U.S. Department of Transportation Federal Aviation Administration |date=August 31, 2018 |access-date=October 30, 2020 |archive-date=September 27, 2022 |archive-url=https://web.archive.org/web/20220927023703/https://rgl.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/0/5a2fac771f141cfc8625836900554c3e/$FILE/H3WE_Rev_27.pdf |url-status=dead }}</ref> The prototypes were delivered to the U.S. Army at Fort Rucker, Alabama, where they competed against the other ten prototype aircraft produced by Bell and Fairchild-Hiller. During the course of the competition, the Bell submission, the ''YOH-4'', was eliminated as being underpowered (it was powered by the {{convert|250|shp|0|abbr=on}} T63-A-5).<ref>McGowen 2005, p. 107.</ref> Accordingly, the bidding for the LOH contract came down to Fairchild-Hiller and Hughes. Ultimately, Hughes was selected as the winner of the competition.<ref>{{cite web |url = http://www.centennialofflight.gov/essay/Aerospace/Hughes/Aero44.htm |title = The Hughes Companies |publisher = Centennial of Flight Commission |first = Judy |last = Rumerman |year = 2003 |access-date = January 28, 2012 |archive-url = https://web.archive.org/web/20120329115359/http://www.centennialofflight.gov/essay/Aerospace/Hughes/Aero44.htm |archive-date = March 29, 2012}}</ref>

left|thumb|OH-6 helicopter in flight During May 1965, the U.S. Army awarded a production contract to Hughes; this initial order for 714 rotorcraft was subsequently increased to 1,300 along with an option for another 114. Hughes's price was $19,860 per airframe, without the engine, while Hiller's price was $29,415 per airframe, also without the engine.<ref name="hr13456">[https://babel.hathitrust.org/cgi/pt?id=uc1.$b655548;view=1up;seq=556 Hearings on military posture and H.R. 13456], p. 7832.</ref> The Hiller design, designated OH-5A,<ref name="hr13456" /> had featured a boosted control system, while the Hughes design did not, a difference that accounted for some of the price increase. Hughes is reported to have told his confidant, Jack Real, that he lost over $100 million to construct 1,370 airframes.<ref name=LockPeople>Cefaratt 2002, p. 77.</ref><ref name=Vertiflite>Real, Jack. "The Real Story." ''Vertiflite'', Fall/Winter 1999, pp. 36–39.</ref> It was reported that Howard Hughes had directed his company to submit a bid at a price beneath the actual production cost of the helicopter in order to secure this order. Accordingly, this tactic had resulted in substantial losses being incurred on the contract with the U.S. Army; the company had allegedly anticipated that an extended production cycle would eventually make the rotorcraft financially viable.<ref>{{cite book |last1 = Real |first1 = Jack G. |first2 = Bill |last2 = Yenne |title = The Asylum of Howard Hughes |publisher = Xlibris |year = 2003 |isbn = 978-1-4134-0876-8}}</ref>{{Self-published inline|certain=yes|date=December 2017}}<ref>{{cite web |last = Day |first = Dwayna Q. |url = http://www.thespacereview.com/article/1045/1 |title = Monster chopper |publisher = The Space Review |date = January 28, 2008 |access-date = April 20, 2012 }}</ref>

Due to price escalations for both the OH-6 and spare components, the U.S. Army opted to reopen bids for the program in 1967.<ref name = "McGowen 112">McGowen 2005, p. 112.</ref> Accordingly, during 1968, Hughes submitted a bid to build a further 2,700 airframes. Stanley Hiller complained to the U.S. Army that Hughes had used unethical procedures; therefore, the Army opened the contract for rebidding by all parties. While Hiller did not participate in the rebidding, Bell opted to, submitting their redesigned Model 206.<ref name = "McGowen 112"/> Following a competitive fly-off, the Army requested the manufacturers to submit sealed bids. Hughes bid $56,550 per airframe, while Bell bid $54,200. Reportedly, Hughes had consulted at the last moment with Real, who recommended a bid of $53,550. Hughes, without informing Real, raised the bid by $3,000, and thus lost the contract to Bell.<ref name=LockPeople /><ref name=Vertiflite /> 1,420 of the OH-6A would be produced, not counting the other derivatives.<ref name="Francillon_248">Francillon 1990, p. 248.</ref>

===Japanese production=== thumb|JGSDF OH-6D A total of 387 OH-6/Hughes 369s were produced under license in Japan by the Japanese aerospace company Kawasaki Heavy Industries. These rotorcraft were operated by several different organisations, the majority of which were based in Japan. Military operators included the Japanese Ground Self-Defense Force (JGSDF), Japanese Maritime Self-Defense Force (JMSDF), and the Japanese Coast Guard. Furthermore, a number of civilian customers also flew Kawasaki-built OH-6s for a variety of missions, including emergency medical services (EMS), law enforcement, and agricultural work.<ref>Aoki 1999, pp. 37–44.</ref><ref name = "McGowen 106">McGowen 2005, p. 106.</ref> Beginning in 2001, the JGSDF OH-6s were supplemented by the Kawasaki OH-1, a more advanced observation helicopter.<ref>{{cite web |url = https://www.forecastinternational.com/archive/disp_pdf.cfm?DACH_RECNO=1007 |title = Rotorcraft Forecast: Kawasaki OH-1 |publisher = Forecast International |date = September 2013}}</ref><ref>McGowen 2005, pp. 215-216.</ref>

==Operational history==

===Entry into service and world records===

During 1966, the OH-6 entered service with the U.S. Army. Its first overseas deployment, as well as into frontline combat, was the Vietnam War. The pilots dubbed the new helicopter ''Loach'', a word created by pronunciation of the LOH (light observation helicopter) acronym of the program that spawned the aircraft. (Loach is also the name for numerous stream-dwelling carnivorous or insectivorous fishes, especially common in South-East Asia, which specialise in hunting among substrates and dense cover.) During 1964, the U.S. Department of Defense issued a memorandum directing that all U.S. Army fixed-wing aircraft be transferred to the U.S. Air Force, while the U.S. Army transitioned to solely operating ''rotor-wing'' aircraft. Accordingly, the U.S. Army's fixed-wing airplane, the Cessna O-1 Bird Dog, which was utilized for artillery observation and reconnaissance flights, would be replaced by the incoming OH-6A.<ref>Adcock 1998, p. 32.</ref>

Early on in the OH-6's career, the type demonstrated its performance in a particularly prominent manner via the setting of 23 individual world records for helicopters during 1966 in the categories of speed, endurance and time to climb.<ref>[http://records.fai.org/rotorcraft/aircraft.asp?id=187 "History of Rotorcraft World Records, List of records established by the 'YOH-6A'."] {{webarchive|url=https://web.archive.org/web/20100729101956/http://records.fai.org/rotorcraft/aircraft.asp?id=187 |date=July 29, 2010 }} Fédération Aéronautique Internationale (FAI). Retrieved: January 11, 2011.</ref> On March 26, 1966, Jack Schwiebold set the closed circuit distance record in a YOH-6A at Edwards Air Force Base, California, flying without landing for 1,739.96 mi (2,800.20 km).<ref>"[http://www.fai.org/fai-record-file/?recordId=11656 FAI Record ID #11656 – Absolute Rotorcraft World Record, Distance over a closed circuit without landing] {{webarchive|url=https://web.archive.org/web/20131203033409/http://www.fai.org/fai-record-file/?recordId=11656 |date=3 December 2013 }}" [http://www.fai.org/fai-record-file/?recordId=786 ID 786] {{webarchive|url=https://web.archive.org/web/20131203033217/http://www.fai.org/fai-record-file/?recordId=786 |date=December 3, 2013 }} Fédération Aéronautique Internationale (FAI). Retrieved: November 28, 2013.</ref> Subsequently, on April 6, 1966, Robert Ferry set the long-distance world record for helicopters by flying from Culver City, California, with over a ton of fuel to Ormond Beach, Florida, covering a total of 1,923.08 nm (2,213.04 mi, 3,561.55 km) in 15 hours, and near the finish at up to {{convert|24,000|ft|m}} altitude. As of 2021, these records still stand.<ref>"[http://www.fai.org/fai-record-file/?recordId=11655 FAI Record ID #11655 – Absolute Rotorcraft World Record, Distance without landing] {{webarchive|url=https://web.archive.org/web/20131203042100/http://www.fai.org/fai-record-file/?recordId=11655 |date=3 December 2013 }}" Fédération Aéronautique Internationale (FAI). Retrieved: November 28, 2013.</ref><ref>Porter, Don. "[http://www.airspacemag.com/history-of-flight/moments-and-milestones-now-thats-good-mileage-608705/?no-ist Now, That’s Good Mileage]" Air & Space/Smithsonian, May 2011. Accessed: April 9, 2014.</ref><ref>Ristine, Jeff. "[http://www.utsandiego.com/news/2009/Feb/02/1m2ferry22928-robert-g-ferry-air-force-veteran-was/ Obituary: Robert G. Ferry; Air Force veteran was record-setting test pilot]" ''San Diego Union-Tribune'', February 2, 2009. Accessed: April 9, 2014.</ref>

===Vietnam War=== thumb|A OH-6A in Vietnam, May 1970 In December 1967, the first OH-6As arrived in South Vietnam.<ref name = "Smithsonian upclose2017"/> Its straightforward design made it easier to maintain than most other helicopters, its relatively compact {{convert|26|ft}} main rotor made it easier to use tight landing zones. While its light aluminum skin could be easily penetrated by small arms fire, it also crumpled and absorbed energy in a crash while the rugged structure protected key systems and its crew. The OH-6 was relatively difficult to shoot down, and its occupants would often survive forced landings that would have likely been fatal onboard other rotorcraft.<ref name = "Smithsonian upclose2017"/> The remaining H-13s were promptly withdrawn in favour of the OH-6s. Typically missions were flown during the daylight, starting at dawn; common roles included the clearance of landing zones and general intelligence/observation flights.<ref name = "Smithsonian upclose2017"/>

[[File:OH-6A and AH-1G Recon Vietnam.jpg|thumb|left|An OH-6A and two AH-1G Cobra helicopters flying a reconnaissance mission near Phuoc Vinh, {{circa|1970}}]]

It became common for OH-6s to operate in teams with other rotorcraft, particularly the Bell AH-1 Cobra attack helicopter. This teamwork was actively encouraged by Army officials, and led to the development of so-called "hunter-killer" tactics that sought to flush out and eliminate hostile ground targets.<ref name = "cobra birth"/><ref name = "Smithsonian upclose2017"/> Such a team would have normally comprised a single OH-6 that would fly relatively slow and at a low altitude while attempting to spot the presence of enemies. If the OH-6 came under fire, the nearby Cobra would then strike at the revealed enemy.<ref>Bishop 2006, {{page needed|date=January 2021}}.</ref><ref>McGowen 2005, pp. 107-108.</ref> As to indicate the position of concealed enemy ground forces, the observer in the OH-6 would mark the spot using a smoke grenade, assisting other units in effectively firing upon them. Over time, the effectiveness of this pairing was such that enemies would often decide against firing on the relatively vulnerable OH-6 in fear of the response that would be unleashed by the AH-1.<ref name = "Smithsonian upclose2017"/><ref name = "cobra birth">{{cite web |url = https://www.smithsonianmag.com/air-space-magazine/13_aug2017-birth-of-the-cobra-180963930/ |title = Birth of the Cobra |publisher = Smithsonian Magazine |date = August 2017 |first = Stephen |last = Joiner}}</ref> Prior to the arrival of the AH-1, "hunter-killer" teams often relied on the firepower from armed models of the Bell UH-1 Iroquois utility helicopter.<ref>Drendel 1983, pp. 9–21.</ref>

During 1972, a pair of heavily modified OH-6As were utilized by the Central Intelligence Agency (CIA) via Air America for a covert wire-tapping mission. The aircraft, dubbed ''500P'' (penetrator) by Hughes, began as an ARPA project, codenamed "Mainstreet", in 1968. Development included test and training flights in Culver City, California (Hughes Airport) and at Area 51 in 1971. In order to reduce their acoustic signature, the helicopters (''N351X'' and ''N352X'') received a four-blade 'scissors' style tail rotor (later incorporated into the Hughes-designed AH-64 Apache), a fifth rotor blade and reshaped rotor tips, a modified exhaust system, and various other performance boosting modifications.<ref name = "Smithsonian wiretap2008"/> During June 1972, they were deployed to a secret base in southern Laos (PS-44), where one of the helicopters was heavily damaged during a training mission late in the summer. On the night of December 5–6, 1972, the remaining helicopter deployed a wiretap near Vinh, North Vietnam; useful information provided from this wiretap was acted on by the United States on several occasions, such as during the Linebacker II campaign and Paris Peace Talks. Shortly thereafter, the aircraft were returned to the U.S., where they were dismantled and converted back to a standard configuration; they continued to be operated as such for a time.<ref name = "Smithsonian wiretap2008">{{cite journal |last = Chiles |first = James R. |url = http://www.airspacemag.com/military-aviation/air-americas-black-helicopter-24960500/ |title = Air America's Black Helicopter |journal = Air & Space Smithsonian |date = February–March 2008 |pages = 62–70 |issn = 0886-2257 |access-date = April 20, 2012}}</ref>

During the early 1970s, Soviet-supplied SA-7 Grail shoulder-launched anti-aircraft missiles emerged amongst North Vietnamese troops; one hit could down a Loach, potentially dealing fatal damage before its crew were aware that they were under fire.<ref name = "Smithsonian upclose2017"/> All American rotorcraft in the theatre had to be operated more cautiously following this development. Reportedly, 964 out of the 1,422 OH-6As produced for the U.S. Army were destroyed in the Vietnam theatre, the majority of these losses being a result of hostile action, typically ground fire. Towards the end of the conflict, the replacement of the OH-6 by the Bell OH-58 Kiowa was imminent across nearly all U.S. Army units. Some crews argued that the Kiowa was nowhere near as nimble as the OH-6, however, the transition proceeded while scouting doctrine was changed to emphasis operations from greater distances.<ref name = "Smithsonian upclose2017">{{cite journal |last = Porter |first = Donald |url = http://www.airspacemag.com/military-aviation/snakes-loaches-180964341/ |title = In Vietnam, These Helicopter Scouts Saw Combat Up Close |journal = Air & Space Smithsonian |publisher = Air & Space Magazine |date = September 2017 |issn = 0886-2257 |access-date = September 13, 2017}}</ref>

===160th Special Operations Aviation Regiment and Task Force 160=== {{Further|MH-6 Little Bird}} thumb|MH-6 Little Bird coming in landing Following the April 1980 failure of Operation Eagle Claw (the attempted rescue of American hostages in Tehran), it was determined that the military lacked aircraft and crews who were trained and prepared to perform special operations missions. To remedy this shortcoming, the Army began developing a special aviation task force to prepare for the next attempt to rescue the hostages: Operation Honey Badger. The architects of the task force identified the need for a small helicopter to land in the most restrictive locations and that was also easily transported on Air Force transport aircraft. They chose the OH-6A scout helicopter to fill that role, and it became known as the ''Little Bird'' compared to the other aircraft in the task force, the MH-60 and the MH-47. As a separate part of the project, armed OH-6As were being developed at Fort Rucker, Alabama.<ref>Durant and Hartov 2006, pp. 48–49.</ref><ref>McGowen 2005, p. 144.</ref>

thumb|left|Troops seated on the outside of an MH-6M Little Bird The pilots selected to fly the OH-6A helicopters came from the 229th Attack Helicopter Battalion and were sent to the Mississippi Army National Guard's Army Aviation Support Facility (AASF) at Gulfport, Mississippi, for two weeks of qualification training in the rotorcraft. When the training was completed, C-141 Starlifter airlifters transported both rotorcraft and crews to Fort Huachuca, Arizona, for two weeks of mission training. The mission training consisted of loading onto C-130 Hercules transport aircraft which would then transport them to forward staging areas over routes as long as {{convert|1000|nmi|km}}. The armed OH-6s from Fort Rucker joined the training program in the fall of 1980.<ref>Durant and Hartov 2006, p. 56.</ref>

Operation Honey Badger was canceled after the hostages were released on January 20, 1981, and for a short while, it looked as if the task force would be disbanded and the personnel returned to their former units. But the Army decided that it would be more prudent to keep the unit in order to be prepared for future contingencies. The task force, which had been designated as Task Force 158, was soon formed into the 160th Aviation Battalion. The OH-6A helicopters used for transporting personnel became the MH-6 aircraft of the Light Assault Company and the armed OH-6As became the AH-6 aircraft of the Light Attack Company.

On October 1, 1986, to help meet the increasing demands for support, the 1-245th Aviation Battalion from the Oklahoma National Guard, which had 25 AH-6 and 23 UH-1 helicopters, was placed under the operational control of the 160th. The 1-245th AVN BN enlisted were sent to the Mississippi Army National Guard's Army Aviation Support Facility (AASF) at Gulfport, Mississippi, for two weeks of qualification training in the aircraft. The following two-week mission was to Yuma for night operation training. The AH/MH Little Birds were lifted by a single C-5 Galaxy, and two C-130 Hercules, along with all support kits for the battalion. Crews trained side by side with the 160th for all operational concepts. The 1-245 modified infantry night vision goggles and worked to develop the necessary skills for rapid deployment with Little Birds and C-130s.<ref>Durant and Hartov 2006, p. 57.</ref>

==Variants== thumb|right|A TH-6B Cayuse helicopter takes off for a training flight from NAS Patuxent River, Maryland thumb|Kawasaki-Hughes OH-6J thumb|A Kawasaki-built OH-6D with five-bladed main rotor.

;YOH-6A ::Prototype ;OH-6A ::Production model powered by a 263 kW (317 shp) Allison T63-A5A turboshaft engine. ;OH-6A NOTAR ::Experimental ;OH-6B ::Re-engined with 313.32 kW (420 shp) Allison T63-A-720 turboshaft engine. ;OH-6C ::Proposed version with 298 kW (400 shp) Allison 250-C20 turboshaft engine, fitted with five rotor blades. ;OH-6J ::Based on the OH-6A, for the JGSDF. Built by Kawasaki Heavy Industries under license in Japan. ;OH-6D ::Based on the Hughes Model 500D, for the JGSDF. Built by Kawasaki.<ref>{{cite web |url = https://janes.ihs.com/CustomPages/Janes/DisplayPage.aspx?DocType=Reference&ItemId=+++1337367&Pubabbrev=JAU_ |title = Jane's Aircraft Upgrades, MD Helicopters (Hughes) Model 500 (Military Versions) |date = November 24, 2011 |access-date = April 29, 2013}}</ref> ;OH-6DA ::Replacement for discontinued OH-6D; JMSDF acquired MD 500Es for training. ;EH-6B ::Special Operations electronic warfare, command post ;MH-6B ::Special Operations ;TH-6B ::Navy derivative of the MD-369H, six McDonnell Douglas TH-6B Conversion-in-Lieu-of-Procurement aircraft for U.S. Naval Test Pilot School test pilot training.<ref>{{cite web |url = http://www.navy.mil/navydata/fact_print.asp?cid=1200&tid=650&ct=1&page=1 |archive-url = https://web.archive.org/web/20060403114619/https://www.navy.mil/navydata/fact_print.asp?cid=1200&tid=650&ct=1&page=1 |url-status = dead |archive-date = April 3, 2006 |title = U.S. Navy Fact Sheet TH-6B helicopter |publisher = United States Navy |date = February 20, 2009 |access-date = January 28, 2012}}</ref> ;AH-6C ::OH-6A modified to carry weapons and operate as a light attack aircraft for the 160th SOAR(A). ;MH-6C ::Special Operations

For other AH-6 and MH-6 variants, see MH-6 Little Bird and Boeing AH-6.

===Military and government operators=== ;Spain * Spanish Navy<ref name=" World Air Forces 2015">{{cite web |url = https://d1fmezig7cekam.cloudfront.net/VPP/Global/Flight/Airline%20Business/AB%20home/Edit/WorldAirForces2015.pdf |title = World Air Forces 2015 |publisher = Flightglobal Insight |year = 2015 |access-date = June 20, 2015}}</ref> ;USA * Atlanta Police Department<ref>{{cite web|url=http://helihub.com/tag/oh-6/ |title=Atlanta Police return to the air |publisher=helihub.com |access-date=February 28, 2013}}</ref> * Chilton County Sheriff's Department<ref>{{cite web |url = http://helihub.com/2012/05/28/chilton-county-sheriff-acquires-oh-6/ |title = Chilton County Sheriff acquires OH-6 |date = May 28, 2012 |publisher = helihub.com |access-date = February 28, 2013}}</ref> * Gainesville Police Department{{cn|date=May 2026}} * United States Army Aviation (See A/MH-6){{cn|date=May 2026}}

===Former operators=== thumb|right|A Danish Army 500M ;Dominican Republic * Dominican Air Force<ref>{{cite web |url = http://www.aeroflight.co.uk/waf/americas/dominican_rep/DomRep-af-EscHel.htm |title = Dominican Republic Air Force Unit History |publisher = aeroflight.co.uk |access-date = February 26, 2013}}</ref> ;Denmark * Royal Danish Army<ref>{{cite web |url = http://www.helis.com/database/modelorg/1204/ |title = Flyvevåbnet 369 HM |access-date = February 26, 2013}}</ref><ref>{{cite book |last = Schrøder |first = Hans |date = 1991 |title = Royal Danish Airforce |editor = Kay S. Nielsen. |publisher = Tøjhusmuseet |pages = 1–64 |isbn = 87-89022-24-6}}</ref> ;Japan * Japan Ground Self-Defense Force<ref name=" World Air Forces 2015"/> * Japan Maritime Self-Defense Force<ref>{{cite web |url = http://www.helis.com/database/modelorg/871/ |title = Japanese Maritime Self-Defence Force OH-6J |publisher = helis.com |access-date = February 28, 2013}}</ref> ;Malta * Air Wing of the Armed Forces of Malta<ref>{{Cite web |url = http://www.aeroflight.co.uk/user/fleet/armed-forces-of-malta-breda-nardi-hughes-nh-500m.htm |title = Breda Nardi Hughes NH.500M in Armed Forces of Malta service |date = May 27, 2016 |publisher = Aeroflight}}</ref> ;Nicaragua * Nicaraguan Air Force<ref>{{cite web |url = http://www.flightglobal.com/pdfarchive/view/1971/1971%20-%202094.html |title = Military Helicopter Market 1971 |publisher = flightglobal.com |access-date = June 20, 2015}}</ref> ;Taiwan * Republic of China Army<ref>{{cite web |url = http://taiwanairpower.org/army/index.html |title = Historical Aircraft |publisher = taiwanairpower.org |access-date = February 26, 2013}}</ref> ;USA * United States Army Aviation (OH-6A/C)<ref>{{cite web |url = http://www.vhpa.org/stories/mh-6c.pdf |title = The last of an old warrior |publisher = vhpa.org |access-date = February 28, 2013}}</ref> * U.S. Border Patrol<ref>{{cite web |url = http://helihub.com/2011/10/22/cbp-retires-the-%e2%80%9cloach%e2%80%9d-after-32-years/ |title = CBP retires the "Loach" after 32 years |publisher = helihub.com |date=October 22, 2011 |access-date = February 26, 2013 |archive-date = September 26, 2013 |archive-url = https://web.archive.org/web/20130926055141/http://helihub.com/2011/10/22/cbp-retires-the-%e2%80%9cloach%e2%80%9d-after-32-years/ |url-status = dead }}</ref> * United States Navy<ref>{{cite web |url = http://www.helis.com/database/modelorg/1814/ |title = US Navy TH-6B Cayuse |publisher = helis.com |access-date = February 26, 2013}}</ref>

==Specifications (OH-6A)== right|450px

{{Aircraft specs |ref=<ref name=JAWA71-72>{{cite book |title = Jane's All the World's Aircraft 1971-72 |year = 1971 |publisher = Sampson Low, Marston & Company |location = London |isbn = 9780354000949 |editor1-last = Taylor |editor1-first = John W.R. |edition = 62nd |pages = 322–323}}</ref> |prime units?= kts  |crew= 2 |capacity= 2 seated passengers or 4 on the floor with rear seats folded/removed |length ft= 30 |length in= 3.75 |length note= including rotors |width ft= |width in= |width note= |height ft= 8 |height in= 1.5 |height note= to top of rotor hub |empty weight lb= 1,229 |empty weight note= |gross weight lb= 2,400 |gross weight note= |max takeoff weight lb= 2,700 |max takeoff weight note= |fuel capacity= {{cvt|61.5|USgal|impgal l|0}} in two 50% self-sealing bladder tanks under rear cabin floor |more general=  |eng1 number= 1 |eng1 name= Allison T63-A-5A |eng1 type= turboshaft engine |eng1 shp= 317 |eng1 note=de-rated to:- ::::{{cvt|252.5|shp|0}} for take-off ::::{{cvt|214.5|shp|0}} maximum continuous

|rot number= 1 |rot dia ft= 26 |rot dia in= 4 |rot area sqft= 544.63 |rot area note= * '''Blade section:''' - NACA 0012<ref>{{cite web |last1 = Lednicer |first1 = David |title = The Incomplete Guide to Airfoil Usage |url = https://m-selig.ae.illinois.edu/ads/aircraft.html |website = m-selig.ae.illinois.edu |access-date = April 16, 2019}}</ref>  |perfhide=

|max speed kts= |max speed note= |max speed mach= |cruise speed kts= 130 |cruise speed note= maximum at sea level ::::{{cvt|116|kn|mph km/h|0}} for maximum range at sea level |never exceed speed kts= 130 |never exceed speed note= at Sea Level |range nmi= 330 |range note= at {{cvt|5000|ft|0}} |combat range nmi= |combat range note= |ferry range nmi= 1,354 |ferry range note= with {{cvt|1300|lb|0}} of fuel |endurance= |ceiling ft= 15,800 |ceiling note= * '''Hover ceiling OGE:''' {{cvt|7300|ft|0}} * '''Hover ceiling IGE:''' {{cvt|11800|ft|0}} |climb rate ftmin= 2,067 |climb rate note={{citation needed|date=May 2020}} |time to altitude= |disk loading lb/sqft= 4.4 |disk loading note= |fuel consumption lb/mi= |power/mass= {{cvt|0.105|shp/lb}} |more performance=  |armament= Provision for packaged armament on port side, including an XM-27 {{cvt|7.62|mm|in|3}} machine-gun with 2,000 - 4,000 rounds of ammunition; or an XM-75 grenade launcher  |avionics= }}

==See also== [[File:Hughes OH-6A Cayuse 506 (67-16506) (6819193438).jpg|thumb|OH-6A Cayuse at The Helicopter Museum, U.K.]] {{aircontent |see also= * U.S. helicopter armament subsystems |related= * Boeing AH-6 * McDonnell Douglas MD 500 Defender * MD Helicopters MH-6 Little Bird |similar aircraft= * {{lwc|Aérospatiale Gazelle}} * {{lwc|Bell ARH-70 Arapaho}} * {{lwc|Bell OH-58 Kiowa}} * {{lwc|Bell YOH-4}} * {{lwc|Cicaré CH-14}} * {{lwc|Fairchild Hiller FH-1100|Fairchild Hiller YOH-5}} * {{lwc|Mil Mi-34}} * {{lwc|PZL SW-4 Puszczyk|PZL SW-4}} * {{lwc|Westland Scout}} |lists= * List of military aircraft of the United States }}

==References== ===Notes=== {{Reflist|group=note}}

===Citations=== {{Reflist}}

===Bibliography=== {{Refbegin}} * {{cite book |title = O-1 Bird Dog In Action – Aircraft No. 87 |last = Adcock |first = Al |publisher = Squadron Signal Publications number 87 |year = 1988 |isbn = 978-0-89747-206-7}} * {{cite journal |last = Aoki |first = Yoshimoto |title = Kawasaki OH-1 |journal = World Air Power Journal |volume = 38 |date =Autumn 1999 |location = London |publisher = Aerospace Publishing |isbn = 1-86184-035-7 |issn = 0959-7050 |pages = 36–45}} * {{cite book |last = Bishop |first = Chris |title = Huey Cobra Gunships |location = New Vanguard. Oxford, UK |publisher = Osprey Publishing Limited |date = 2006 |isbn = 1-84176-984-3}} * {{cite book |title = Lockheed: The People Behind the Story |last = Cefaratt |first = Gil |publisher = Turner Publishing Company |year = 2002 |isbn = 978-1-56311-847-0}} * {{cite book |last = Drendel |first = Lou |title = Huey |location = Carrollton, Texas |publisher = Squadron/Signal Publications |date = 1983 |isbn = 0-89747-145-8}}. * {{cite book |title = The Night Stalkers |last1 = Durant |first1 = Michael J. |last2 = Hartov |first2 = Steven |last3 = Durant |first3 = Michael |publisher = Penguin Group |year = 2007 |isbn = 978-0-399-15392-1 |author-link = Michael Durant}} * {{cite book |title = McDonnell Douglas Aircraft Since 1920 |last = Francillon |first = René J. |publisher = Naval Institute Press |year = 1998 |isbn = 978-0-87021-428-8}} * {{cite book |title = Primer of the Helicopter War |last1 = Holley |first1 = Charles |last2 = Sloniker |first2 = Mike |publisher = Nissi Publishing |year = 1997 |isbn = 978-0-944372-11-1}} * {{cite book |title = Low Level Hell |last1 = Mills |first1 = Hugh |last2 = Anderson |first2 = Robert |publisher = Presidio Press |year = 1992 |isbn = 978-0-89141-719-4}} * {{cite book |last = McGowen |first = Stanley S. |title = Helicopters: An Illustrated History of Their Impact |url = https://books.google.com/books?id=xLis8p7uLaUC&pg=PA159 |year = 2005 |publisher = ABC-CLIO |isbn = 978-1-85109-468-4}} * {{cite book |title = The McDonnell Douglas OH-6A Helicopter |last1 = Porter |first1 = Donald |publisher = Diane Publishing Company |year = 1990 |isbn = 978-0-8306-8619-3}} {{Refend}}

==External links== {{Commons category|OH-6 Cayuse}} * [https://web.archive.org/web/20120214081542/http://www.warbirdregistry.org/heloregistry/oh6registry.html Warbird Registry – OH-6 Cayuse] – Tracking the histories of OH-6s that survived military service.

{{DEFAULTSORT:Hughes Oh-6 Cayuse}} H-6 Little Bird Category:1960s United States helicopters Category:1960s United States military reconnaissance aircraft Category:1960s United States military utility aircraft Category:Aircraft first flown in 1963 Category:Aircraft with skid landing gear Category:Hughes aircraft Category:Kawasaki aircraft Category:Single-rotor helicopters Category:Single-turbine helicopters Hughes H-6