View source for Engineering:AgustaWestland AW101

{{short description|Multi-role helicopter family by AgustaWestland}}
{|{{Infobox aircraft begin
 |name= AW101 (EH101) <br />Merlin
 |image= File:Italy - Navy EHI EH-101 (cropped).jpg
 |caption= An Italian Navy AW101
}}{{Infobox aircraft type
 |type= Anti-submarine warfare, medium-lift [[Engineering:Military transport aircraft#Transport helicopters|transport]], search and rescue and [[Engineering:Utility helicopter|utility helicopter]]
 |national origin= United Kingdom/Italy
 |manufacturer= Agusta<br />Westland Helicopters<br />AgustaWestland<br />Finmeccanica<br />Leonardo S.p.A.<ref>{{cite web|title=Finmeccanica Approves Merger And Spin-Off Operations For The Implementation of The Divisionalisation Process|url=http://www.leonardocompany.com/en/-/fusione-cessione-divisionalizazzione-merger-spin-off|access-date=16 June 2016|archive-url=https://web.archive.org/web/20160808063008/http://www.leonardocompany.com/en/-/fusione-cessione-divisionalizazzione-merger-spin-off|archive-date=8 August 2016|url-status=live}}</ref>
 |designer=
 |first flight= 9 October 1987
 |introduced= 1999<ref name="1 aug">AgustaWestland 2008, p. 1.</ref>
 |retired=
 |status= In service
 |primary user= Royal Navy
 |more users= {{wipe|Royal Air Force}} (historical) <br />Italian Navy <br />{{wipe|Royal Danish Air Force}} <!-- Limited to THREE (3) 'more users' here (4 total users). Separate users with <br />. Canada is covered at [[Engineering:AgustaWestland CH-149 Cormorant|AgustaWestland CH-149 Cormorant]]. -->
 |produced= 1990s-present
 |number built=
 |variants with their own articles= [[Engineering:AgustaWestland CH-149 Cormorant|AgustaWestland CH-149 Cormorant]] <br />Lockheed Martin VH-71 Kestrel
}}
|}

The '''AgustaWestland AW101''' is a medium-lift [[Engineering:Helicopter|helicopter]] in military and civil use. First flown in 1987, it was developed by a joint venture between Westland Helicopters in the United Kingdom and Agusta in Italy in response to national requirements for a modern naval utility helicopter. Several operators, including the armed forces of Britain, Denmark, and Portugal, use the name '''Merlin''' for their AW101 aircraft.<ref>{{cite web |url= http://www.emfa.pt/www/aeronavesdetalhe.php?lang=ing&cod=eh101 |title= EH-101 Merlin factsheet |publisher= Portuguese Air Force |access-date= 5 February 2010 |archive-url= https://web.archive.org/web/20090620003601/http://www.emfa.pt/www/aeronavesdetalhe.php?lang=ing&cod=eh101 |archive-date= 20 June 2009 |url-status= dead |df= dmy-all}}</ref><ref>{{cite web |url= http://forsvaret.dk/FTK/Factsheets/ |title= Danish Airforce factsheet |publisher= Danish Airforce |access-date=5 February 2010|archive-url= https://web.archive.org/web/20080618040906/http://forsvaret.dk/FTK/Factsheets/|archive-date=18 June 2008 |url-status=dead}}</ref> It is manufactured at factories in Yeovil, England and Vergiate, Italy; licensed assembly work has also taken place in {{wipe|Japan}} and the {{wipe|United States}}.

Prior to 2007, the aircraft had been marketed under the designation '''EH101'''. The original designation was EHI 01, from the name given to the Anglo-Italian joint venture – European Helicopter Industries – but a transcription error changed this to EH101.<ref>{{cite book|last1=Brown|first1=D. K.|last2=Moore|first2=George|title=Rebuilding the Royal Navy: Warship Design Since 1945|url=https://books.google.com/books?id=PyDOAwAAQBAJ&pg=PA110|year=2012|publisher=Seaforth Publishing|isbn=978-1-84832-150-2|page=110}}</ref> In 2000, Westland Helicopters and Agusta merged to form AgustaWestland, leading to the type's current designation.

The AW101 entered into service in 1999 and has since replaced several older helicopter types, such as the Sikorsky Sea King, performing roles such as medium-sized transport, anti-submarine warfare, search and rescue, and ship-based utility operations. The {{wipe|Royal Canadian Air Force}} (RCAF) operates the [[Engineering:AgustaWestland CH-149 Cormorant|CH-149 Cormorant]] variant for air-sea rescue. Another variant, the Lockheed Martin VH-71 Kestrel, was produced to serve in the US presidential transport fleet before the program was cancelled and the aircraft sold off. Civil operators use the AW101 for passenger and VIP transportation. The type has been deployed to active combat theatres, such as in support of coalition forces during the Iraq War and the War in Afghanistan.

==Development==

===Origins===
In 1977, the UK Ministry of Defence issued a requirement for an anti-submarine warfare (ASW) helicopter to replace the Royal Navy's [[Engineering:Westland Sea King|Westland Sea King]]s, which were becoming inadequate in the face of advances in Soviet submarine technology. Westland Helicopters put together a proposal, designated '''WG.34''', for a three-engined helicopter of similar dimensions to the Sea King; the WG.34 was to feature more autonomy and a greater range than its predecessor.<ref>{{cite web |url= http://www.flightglobal.com/PDFArchive/View/1978/1978%20-%203004.html |title= Royal Navy keeps its wings |work= Flight International |date= 25 November 1978 |pages= 1926–1927 |access-date= 26 January 2008 |archive-url= https://web.archive.org/web/20081206104008/http://www.flightglobal.com/pdfarchive/view/1978/1978%20-%203004.html |archive-date= 6 December 2008 |url-status= live}}</ref> At the same time, the Italian Navy (''Marina Militare'') was also considering the replacement of its fleet of Sea Kings, which had been built by the Italian company Agusta; Westland and Agusta soon began talks regarding the joint development of a successor helicopter.<ref>{{cite web |url= http://www.defense-aerospace.com/cgi-bin/client/modele.pl?prod=19144&shop=dae&modele=feature |title= Agusta, Westland and Europe |first= Giovanni de |last= Briganti |publisher= defense-aerospace.com |access-date= 5 February 2010 |archive-url= https://web.archive.org/web/20110929030811/http://www.defense-aerospace.com/cgi-bin/client/modele.pl?prod=19144&shop=dae&modele=feature |archive-date= 29 September 2011 |url-status= live}}</ref>

Agusta and Westland finalised an agreement to work on the project together, and formed a jointly owned new company, EH Industries Limited (EHI), to pursue the development and marketing of the new helicopter to potential operators. On 12 June 1981, the UK government confirmed its participation in the project, allocated an initial budget of £20 million to develop nine pre-series examples.<ref>Aeronautica & Difesa, No. 14, Dec 1987, p. 34.</ref> A major agreement, which secured funding for the majority of the EH101's development program, was signed by both the British and Italian governments in 1984.<ref>{{cite journal |doi= 10.1108/eb035956 |url= http://www.emeraldinsight.com/Insight/viewContentItem.do?contentType=Article&contentId=1683254 |archive-url= https://archive.today/20120730131320/http://www.emeraldinsight.com/Insight/viewContentItem.do?contentType=Article&contentId=1683254 |url-status= dead |archive-date= 30 July 2012 |title= Go-ahead for Anglo-Italian EH101 Helicopter |journal= Aircraft Engineering and Aerospace Technology |volume= 56 |issue= 3 |year= 1984 |pages= 11–12}}</ref> At the 1985 Paris Air Show, Agusta showed a mock-up of a utility version of the new helicopter, leading to a more generalised design that could be customised to meet the needs of various civilian or military customers. The first prototype flew on 9 October 1987.<ref>{{cite journal |title= The EH101 helicopter: A fully integrated international collaborative program |first= Stephen |last= Twigge |journal= Defense & Security Analysis |volume= 8 |issue= 2 |date= August 1992 |pages= 133–146 |doi=10.1080/07430179208405535}}</ref>

In 1987, Canada selected the EH101 to replace their Sea Kings in the anti-submarine warfare and search and rescue roles. The EH101's third engine and increased range compared favorably with rival aircraft, such as the Sikorsky Seahawk. The range and de-icing capability were also seen as vital for North Atlantic operations.<ref>Martin 1996, p. 137.</ref> The fledgling EH101, of which up to 50 were on order to replace the Canadian Armed Forces's (CAF) Sea Kings, found itself subject to a wider political battle between the Conservative and Liberal parties, the latter viewing the aircraft as too costly.<ref>{{cite news |url= https://pqasb.pqarchiver.com/thestar/access/456445171.html?dids=456445171:456445171&FMT=ABS&FMTS=ABS:FT&type=current&date=Jul+28%2C+1992&author=Audrey+McLaughlin&pub=Toronto+Star&desc=Cold+War+'copters+a+waste+of+money&pqatl=google |title= Cold War 'copters a waste of money |first= Audrey |last= McLaughlin |work= Toronto Star |date= 28 July 1992 |access-date= 5 July 2017 |archive-url= https://web.archive.org/web/20121108061424/http://pqasb.pqarchiver.com/thestar/access/456445171.html?dids=456445171:456445171&FMT=ABS&FMTS=ABS:FT&type=current&date=Jul+28%2C+1992&author=Audrey+McLaughlin&pub=Toronto+Star&desc=Cold+War+'copters+a+waste+of+money&pqatl=google |archive-date= 8 November 2012 |url-status= live}}</ref> Critics attacked the EH101 purchase as excessive and unnecessary after the [[History:Cold War|Cold War]]'s end in the early 1990s.<ref>Martin 1996, pp.&nbsp;108–109.</ref> Wide-ranging cost estimates were presented by both proponents and opponents of the EH101 procurement, with opponents backing life extensions of Sikorsky CH-124 Sea King and Boeing Vertol CH-113 Labrador helicopter fleets.<ref>Dobbin 1993, pp.&nbsp;108–109.</ref><ref>Martin 1996, pp.&nbsp;124–125.</ref> The EH101 controversy was seen as a factor in the 1993 Canadian federal election.<ref>Martin 1996, p. 131.</ref> The order was cancelled by the new Liberal government in 1993 resulting in a $470 million cancellation fee.<ref>{{cite news |url= https://www.nytimes.com/1996/01/24/business/international-briefs-canada-settles-claim-on-canceled-helicopters.html |title= Canada settles claim on Canceled Helicopters |work= The New York Times |date= 24 January 1996 |access-date= 14 February 2017 |archive-url= https://web.archive.org/web/20141129214850/http://www.nytimes.com/1996/01/24/business/international-briefs-canada-settles-claim-on-canceled-helicopters.html |archive-date= 29 November 2014 |url-status= live}}</ref><ref>{{cite web|url=http://www.cbc.ca/news/politics/sea-kings-possible-replacement-familiar-to-canadians-1.1700833|title=Sea Kings' possible replacement familiar to Canadians|date=6 September 2013|work=cbc.ca|access-date=23 July 2015|archive-url=https://web.archive.org/web/20150710001955/http://www.cbc.ca/news/politics/sea-kings-possible-replacement-familiar-to-canadians-1.1700833|archive-date=10 July 2015|url-status=live}}</ref>

===Into production===
Several pre-production aircraft were assembled during the late 1980s and early 1990s. The first pre-production aircraft had its first flight powered by General Electric CT7-2A engines on 9 October 1987.<ref name="First_Flight">{{cite web |url= https://vertipedia.vtol.org//milestones/getMilestone?milestoneid=162 |title= First flight of the prototype (PP1) of the EH Industries EH101 Type Series |publisher= Vertipedia |date= 19 October 1987 |access-date= 29 June 2020 }}</ref>  Flight tests were suspended for six months following the crash of the second pre-production aircraft on 21 January 1993. On 6 June 1993, the first EH101 took its maiden flight with the [[Engineering:Rolls-Royce Turbomeca RTM322|Rolls-Royce Turbomeca RTM322]] [[Engineering:Turboshaft|turboshaft]] engine.<ref name="Janes">{{cite web |url= http://articles.janes.com/articles/Janes-All-the-Worlds-Aircraft/AgustaWestland-AW101-International.html |title= AgustaWestland AW101 |publisher= Jane's All the World's Aircraft |date= 13 June 2011 |access-date= 4 January 2012 |archive-url= https://web.archive.org/web/20110418065605/http://articles.janes.com/articles/Janes-All-the-Worlds-Aircraft/AgustaWestland-AW101-International.html |archive-date= 18 April 2011 |url-status= live}}</ref> Nine prototypes were built to explore military and civil applications, including a "heliliner" configuration.<ref>Lake 2007, pp. 122–125.</ref><ref name="RAF museum">{{cite web |url=http://www.rafmuseum.org.uk/london/collections/aircraft/aircraft-history/X003-1404%20Merlin%20PP8.pdf |title=Individual History: EH Industries EH101 PP8/G-OIOI/ZJ116 |publisher=RAF Museum |access-date=17 January 2012 |archive-url=https://www.webcitation.org/67M7wQqll?url=http://www.rafmuseum.org.uk/london/collections/aircraft/aircraft-history/X003-1404%20Merlin%20PP8.pdf |archive-date=2 May 2012 |url-status=dead}}</ref> In February 1995, Britain formally placed its first order for a total of 22 EH101s;<ref>{{cite news |url= https://www.independent.co.uk/news/business/westland-tipped-for-mod-order-1574476.html |title= Westland tipped for MoD order |work= The Independent |first= Russell |last= Hotten |date= 23 February 1995 |location= London |access-date= 23 August 2017 |archive-url= https://web.archive.org/web/20160829014903/http://www.independent.co.uk/news/business/westland-tipped-for-mod-order-1574476.html |archive-date= 29 August 2016 |url-status= live}}</ref> this was quickly followed by Italy's order for 16 EH101s in October 1995.<ref>{{cite news |url= http://www.accessmylibrary.com/article-1G1-17564657/italian-navy-orders-16.html |title= Italian navy orders 16 EH-101 helicopters |work= Defense Daily |date= 10 October 1995}}</ref> The EH101 order was not without controversy, the RAF had declared its preference for an all-[[Engineering:Boeing Chinook (UK variants)|Chinook]] fleet; also, [[Company:Boeing|Boeing]] allegedly offered cheaper terms for the Chinook.<ref>Cooper 1997, pp. 69, 72.</ref> RAF deliveries began in 1997; RN deliveries started the following year.<ref>{{cite journal |url= http://www.emeraldinsight.com/Insight/viewContentItem.do?contentType=Article&hdAction=lnkpdf&contentId=876450 |title= Advances in rotorcraft |first= Terry |last= Ford |journal= Aircraft Engineering and Aerospace Technology |volume= 69 |issue= 5 |year= 1997 |pages= 447–452 |doi= 10.1108/00022669710367434}}</ref><ref>Evans 2004, p. 24.</ref>

Following the merger of Westland and Agusta to form AgustaWestland in 2000,<ref>{{cite news |url= http://news.bbc.co.uk/1/hi/business/852612.stm |title= Westland merger confirmed |work= BBC News |date= 26 July 2000 |access-date= 6 February 2010 |archive-url= https://web.archive.org/web/20040722014545/http://news.bbc.co.uk/1/hi/business/852612.stm |archive-date= 22 July 2004 |url-status= live}}</ref><ref>{{cite news |url= https://www.telegraph.co.uk/finance/2886459/Italians-take-controls-at-UK-helicopter-maker.html |title= Italians take controls at UK helicopter maker |work= The Daily Telegraph |first= Christopher |last= Hope |date= 27 May 2004 |location= London |access-date= 2 April 2018 |archive-url= https://web.archive.org/web/20181118112702/https://www.telegraph.co.uk/finance/2886459/Italians-take-controls-at-UK-helicopter-maker.html |archive-date= 18 November 2018 |url-status= live}}</ref> there was no need for the separate EHI entity; the EH101 was formally re-branded as the AW101 in 2007.<ref>{{cite web |url= http://www.aviationtoday.com/rw/personalcorporate/exectransport/14508.html |title= Rotorcraft Report: AgustaWestland |date= 1 August 2007 |work= Rotor & Wing |publisher= Access Intelligence, LLC |quote= The company re-branded its medium-lift EH101 transport the AW101 to reflect&nbsp;... the full integration of its Agusta and Westland&nbsp;... |access-date= 11 August 2007 |archive-url= https://web.archive.org/web/20070808143316/http://www.aviationtoday.com/rw/personalcorporate/exectransport/14508.html |archive-date= 8 August 2007 |url-status= live}}</ref> By April 2009, more than 180 AW101s had been sold worldwide; the combined operational fleet had also accumulated a total of 170,000 flying hours.<ref name="kington">{{cite news |first= Tom |last= Kington |url= http://www.defensenews.com/story.php?i=4058317 |title= As U.S. Sales Slip Away, AW101 Closes On Italian CSAR Order |work= Defense News |date= 27 April 2009}}{{dead link|date=August 2021|bot=medic}}{{cbignore|bot=medic}}</ref>

===Further developments===
In November 2007, Algeria signed a contract for 6 AW101 helicopters.<ref name="Algeria">{{cite web |url= http://www.avionews.com/index.php?corpo=see_news_home.php&news_id=1082317&pagina_chiamante=index.php |title= AgustaWestland, 400 million Euro contract in Algeria |publisher= Avionews |date= 20 November 2007 |access-date= 25 November 2007 |archive-url= https://web.archive.org/web/20110707194255/http://www.avionews.com/index.php?corpo=see_news_home.php&news_id=1082317&pagina_chiamante=index.php |archive-date= 7 July 2011 |url-status= live}}</ref> In August 2012, it was reported that Algeria had signed an agreement with AgustaWestland for the provision of up to 80 helicopters, 42 of which were to be AW101s. Under the terms of this arrangement, early aircraft were to be manufactured by AgustaWestland, while Algeria was to commence the assembly of some AW101s later on.<ref>{{cite web |url= http://www.defenceweb.co.za/index.php?option=com_content&view=article&id=27167:algeria-orders-six-super-lynx-helicopters&catid=35:Aerospace&Itemid=107 |title= Algeria orders six Super Lynx helicopters |publisher= defenceweb.co.za |date= 8 August 2012 |access-date= 13 August 2012 |archive-url= https://web.archive.org/web/20120826074328/http://www.defenceweb.co.za/index.php?option=com_content&view=article&id=27167:algeria-orders-six-super-lynx-helicopters&catid=35:Aerospace&Itemid=107 |archive-date= 26 August 2012 |url-status= live}}</ref>

By September 2013, AgustaWestland was in the process of acquiring civil certification for the AW101, prospective customers include offshore oil platform operators and VIP clients.<ref name="perry">Perry, Dominic. [http://www.flightglobal.com/news/articles/agustawestland-pursues-new-aw101-sales-avenues-390592/ "AgustaWestland pursues new AW101 sales avenues"] {{Webarchive|url=https://web.archive.org/web/20130920171331/http://www.flightglobal.com/news/articles/agustawestland-pursues-new-aw101-sales-avenues-390592/ |date=20 September 2013}}. ''Flight International'', 17 September 2013. Accessed: 17 September 2013.</ref> As of February 2014, AgustaWestland was considering adapting the AW101 as a heavyweight [[Engineering:Unmanned aerial vehicle|unmanned aerial vehicle]], it is proposed that in this configuration an AW101 could be optionally manned.<ref>Drwiega, Andrew. [http://www.aviationtoday.com/rw/commercial/offshore/Thinking-Outside-The-Box-In-Italy_81369.html#.UxYY9U3iumQ "Thinking Outside The Box In Italy ."] {{Webarchive|url=https://web.archive.org/web/20140304221021/http://www.aviationtoday.com/rw/commercial/offshore/Thinking-Outside-The-Box-In-Italy_81369.html#.UxYY9U3iumQ |date=4 March 2014}} ''Rotor&Wing'', 28 February 2014.</ref>

On 7 June 2010, it was announced that Boeing had acquired a manufacturing license and the rights from AgustaWestland for US production of a localised AW101 variant, designated as the Boeing 101.<ref>[http://boeing.mediaroom.com/index.php?s=20295&item=1248 "Boeing Secures All Rights to AgustaWestland AW101 for US Navy VXX Presidential Helicopter Program."] {{Webarchive|url=https://web.archive.org/web/20140304220454/http://boeing.mediaroom.com/index.php?s=20295&item=1248 |date=4 March 2014}} ''Boeing'', 7 June 2010.</ref> In October 2012, the AW101 was submitted in a {{wipe|U.S. Air Force}} competition to replace the HH-60 Pave Hawk; however, the bid was dropped three months later.<ref>[http://www.flightglobal.com/news/articles/sikorsky-last-bidder-standing-in-usafs-combat-rescue-helicopter-battle-380157/ Sikorsky last bidder standing in USAF's combat rescue helicopter battle] {{Webarchive|url=https://web.archive.org/web/20130322055249/http://www.flightglobal.com/news/articles/sikorsky-last-bidder-standing-in-usafs-combat-rescue-helicopter-battle-380157/ |date=22 March 2013}}. ''Flight International'', 12 December 2012.</ref>

==Design==

===Overview===
[[File:Merlin Airframe Material.jpg|thumb|right|AW101 airframe diagram]]

The AW101 Merlin follows a conventional design layout, but makes use of advanced technologies, such as the design of the [[Engineering:Helicopter rotor|rotor]] blades, avionics systems, and extensive use of composite materials.<ref>Gunston and Spick 1986, p. 112.</ref> The fuselage structure is modular and comprises an aluminium-lithium alloy, designed to be both light and damage-resistant.<ref>{{cite journal |title= Polymer Composites for Helicopter Structures |first= N.G. |last= Marks |publisher= Met. Mater. |volume= 5 |issue= 8 |pages= 456–459 |date= August 1989}}</ref> The AW101 is designed for operating in extreme weather conditions; it is fitted with a [[Chemistry:De-icing|de-icing]] system and rated to operate in temperatures ranging between −45 and +50&nbsp;°C.<ref name="craw">Crawford 2003, p. 27.</ref> The aircraft's control systems allow the AW101 to maintain a stable hover in {{convert|40|kn|km/h|abbr=on|order=flip}} [[Physics:Crosswind|crosswind]]s.<ref name="1 aug" />

An [[Physics:Active vibration control|active vibration control]] system, known as the ''active control of structural response system'', reduces airframe vibration by up to 80% which increases crew comfort and minimises buildup of stress on the airframe.<ref>Jackson 2009, p. 274.</ref> The cockpit is fitted with armoured seats for the crew, and can withstand an impact velocity of over 10&nbsp;m/s. Dual flight controls are provided, though the AW101 can be flown by a single person.<ref name="craw" /> The pilots' instrument displays include six full-colour high-definition screens and an optional mission display; a digital map or forward looking infrared (FLIR) display can also be installed.<ref>{{cite journal |url= http://spie.org/x648.html?product_id=210962 |title= Color AMLCD displays for the EH-101 helicopter |first= J. Colin |last= Prince |author2= James F. Farrell |author3= H. Woo |author4= P. Yu |author5= Ray Leerentveld |journal= Cockpit Displays Ii |publisher= SPIE |volume= 2462 |pages= 234–240 |date= 5 June 1995 |doi= 10.1117/12.210962 |bibcode= 1995SPIE.2462..234P |s2cid= 111311180 |access-date= 6 February 2010 |archive-url= https://web.archive.org/web/20130704192614/http://spie.org/x648.html?product_id=210962 |archive-date= 4 July 2013 |url-status= live}}</ref>

===Powerplant===
[[File:2010-06-11 EH101 Airforce EDDB 01.jpg|thumb|left|Probe for aerial refuelling]]

The AW101 is powered by three [[Engineering:Turboshaft|turboshaft]] engines. Initially the [[Engineering:Rolls-Royce Turbomeca RTM322|Rolls-Royce Turbomeca RTM322]] and the General Electric CT7 were the two available engine types, but by 2020 new aircraft were only being sold with the CT7-8E.<ref>{{cite web |url=https://www.leonardocompany.com/documents/20142/9843821/AW101+brochure_Gen2020.pdf?t=1580313105666 |title=AW101 brochure |last= |first= |date= |website=www.leonardocompany.com |publisher= |access-date=5 January 2021 |quote=}}</ref>  The RTM322 powerplant was specifically developed for the AW101;<ref>{{cite journal |url= http://www.informaworld.com/smpp/content~content=a791611879&db=all |title= Rolls-Royce—a fount of military power |first= Mike |last= Witt |publisher= RUSI Journal |volume= 135 |issue= 1 |pages= 39–45 |date= Spring 1990}}</ref> it was subsequently adopted on the [[Engineering:AgustaWestland Apache|AgustaWestland WAH-64 Apache]] and the [[Engineering:NHIndustries NH90|NHIndustries NH90]] helicopters.<ref>{{cite web |url= http://www.rolls-royce.com/defence/products/helicopters/rtm_322.jsp |title= RTM322 |access-date=16 March 2009 |publisher= Rolls-Royce plc| archive-url= https://web.archive.org/web/20090304223426/http://www.rolls-royce.com/defence/products/helicopters/rtm_322.jsp| archive-date= 4 March 2009 | url-status= live}}</ref> According to Rolls-Royce, about 80% of AW101s use the RTM322, .<ref name="rtm322">[http://www.rolls-royce.com/Images/RTM322_tcm92-6703.pdf "RTM322 turboshaft"] ''Rolls-Royce plc''. Retrieved 21 April 2012. {{webarchive |url=https://web.archive.org/web/20120609172810/http://www.rolls-royce.com/Images/RTM322_tcm92-6703.pdf |date=9 June 2012}}</ref>

The engines power an {{convert|18.59|m|abbr=on}} diameter five-bladed main rotor. The rotor blades are constructed from carbon/glass with [[Engineering:Nomex|nomex]] honeycomb and rohacell foam, edged with [[Chemistry:Titanium alloy|titanium alloy]] in a [[Chemistry:Sandwich-structured composite|sandwich construction]]. The shaping of the main rotor blades is derived from the BERP rotor blades first used on the [[Engineering:Westland Lynx|Westland Lynx]]. This blade design improves aerodynamic efficiency at the blade tip and reduces the acoustic signature.<ref>Prouty, Ray. ''Helicopter Aerodynamics'', Helobooks, 2003.</ref>{{pageneeded|date=January 2021}} Improved BERP IV rotors have since been developed; when installed, this increases the AW101's maximum takeoff weight.<ref name="kington" />

Each engine is supplied by a separate 1,074 litre (276 US Gallon, 230 Imperial Gallon) [[Engineering:Fuel tank|fuel tank]] using dual booster pumps. Optional fourth and fifth tanks can be added to act as a reservoir supply, topping up the main tanks during flight, increasing [[Astronomy:Range (aeronautics)|range]] or endurance.<ref name="jawa03 p236">Jackson 2003, p. 236.</ref> The AW101 can also be fitted with a probe for aerial refuelling.<ref name="jawa03 p236" /> [[Engineering:Self-sealing fuel tank|Self-sealing fuel tank]]s are an optional item to be selected by the customer.<ref name="4 aug">AgustaWestland 2008, p. 4.</ref> An inlet particle separator system can be installed, protecting the engine when operating in sandy environments.<ref name="AW_p12">AgustaWestland 2008, p. 12.</ref>

===Armament and defensive systems===
[[File:Westland.eh101.merlin.fairford.arp.jpg|thumb|right|A Merlin HM1 loaded with a Sting Ray torpedo]]

Most variants of the AW101 are equipped with self-defence systems, such as chaff and [[Earth:Flare|flare]] dispensers, directed infrared countermeasures (infrared jammers), ESM (electronic support measures in the form of [[Engineering:Radio frequency|RF]] heads), and a laser detection and warning system.<ref>{{cite news |url= http://www.accessmylibrary.com/coms2/summary_0286-27217675_ITM |title= Nordic Helo paths diverge |quote= The first had no specific requirements other than that it needed to include an EW controller, a radar-warning receiver, a missile-warning system, a laser-warning system, and a chaff/flare dispenser, with an optional RF jammer |date= 1 November 2001 |last= Rivers |first= Brendan P |work= Journal of Electronic Defense}}</ref> British Merlins have been outfitted with protective armour against small-arms fire.<ref name="ballistic armour" /> A side-mounted forward looking infrared (FLIR) imaging sensor has been fitted to some variants.<ref>{{cite news |url= http://www.accessmylibrary.com/coms2/summary_0286-26263106_ITM |title= FLIR Systems awarded contract to provide Thermal Imaging Systems for Royal Danish and Portuguese Air Forces; Contract valued at more than $10 million |date= 2 October 2002 |publisher= Business Wire}}</ref>

Two hardpoints are present in the underside of the airframe on which the HM1 model can carry four Sting Ray torpedoes or Mk 11 Mod 3 depth charges.{{citation needed|date=March 2018}} Some customers have chosen to deploy the Marte anti-ship missile on the AW101;<ref>{{cite web |url= http://www.defenceweb.co.za/index.php?option=com_content&view=article&id=26812:airbus-military-c295-carries-marte-mk2s-anti-ship-missile-for-first-time&catid=35:Aerospace&Itemid=107 |title= Airbus Military C295 carries Marte Mk2/S anti-ship missile for first time |publisher= Airbus Military |date= 17 July 2012 |access-date= 13 August 2012 |archive-url= https://web.archive.org/web/20151019151945/http://www.defenceweb.co.za/index.php?option=com_content&view=article&id=26812:airbus-military-c295-carries-marte-mk2s-anti-ship-missile-for-first-time&catid=35:Aerospace&Itemid=107 |archive-date= 19 October 2015 |url-status= live}}</ref> as of 2011, the Royal Navy is considering equipping their Merlin fleet with an anti-surface missile.<ref>{{cite web |url= http://www.forecastinternational.com/samples/F658_CompleteSample.pdf |title= The Market for Anti-Ship Missiles |publisher= Forecast International |date= August 2011 |page= 4 |access-date= 7 January 2012 |archive-url= https://www.webcitation.org/67BQh2T6t?url=http://www.forecastinternational.com/samples/F658_CompleteSample.pdf |archive-date= 25 April 2012 |url-status= live}}</ref> The Mk1, Mk3 and Mk3A variants can mount general purpose machine guns in up to five locations in the main cabin, aimed out of both door and window apertures. AgustaWestland has examined the integration of [[Engineering:Rocket (weapon)|rocket]]s and additional ground-attack weapons.<ref name="kington" />

===Avionics===
Westland and [[Company:IBM|IBM]] formed a consortium in 1991 to perform the helicopter's complex systems integration.<ref>Matthews 1992, p. 82.</ref> The AW101 features a network of helicopter management and mission systems designed to reduce pilot workload and enable the helicopter to undertake a wide variety of missions. A digital [[Fly-by-wire|automatic flight control system]] (AFCS) is employed by the AW101. The AFCS allows the operation of a four-axis (pitch, roll, yaw and [[Engineering:Helicopter flight controls#Collective|collective]]) [[Engineering:Autopilot|autopilot]] and the automatic stabilisation system, and is linked in with the aircraft's flight management systems.<ref>Moir and Seabridge 2008, pp.&nbsp;343–345.</ref> The AFCS, manufactured by Smiths Aerospace, is a [[Engineering:Duplex (telecommunications)|dual-duplex]] system using two flight computers to provide [[Engineering:Redundancy (engineering)|redundancy]] and fault-tolerance.<ref name="avionics today">{{cite web |url= http://www.aviationtoday.com/av/rotocraft/Agusta-Westlands-EH101_733.html |title= Agusta Westland's EH101 |publisher= Avionics Today |date= 1 February 2005 |access-date= 6 January 2012 |archive-url= https://web.archive.org/web/20140408214018/http://www.aviationtoday.com/av/rotocraft/Agusta-Westlands-EH101_733.html |archive-date= 8 April 2014 |url-status= live}}</ref>

The AW101's navigation system includes a GPS receiver and [[Earth:Inertial navigation system|inertial navigation system]], VHF omnidirectional radio range (VOR), instrument landing system (ILS), TACAN, and automatic direction finding. The Mk1 and Mk3 are equipped with a Doppler velocity system (DVS) which provides relative ground velocities;<ref>{{cite web |url=http://www.selex-comms.com/internet/localization/IPC/media/docs/ANV-353_EN_LR.pdf |title=Doppler Velocity Sensor ANV-353 |publisher=Selex Communications |access-date=30 January 2012 |archive-url=https://www.webcitation.org/67M7whFaR?url=http://www.selex-comms.com/internet/localization/IPC/media/docs/ANV-353_EN_LR.pdf |archive-date=2 May 2012 |url-status=dead}}</ref> the DVS is also linked into the AFCS as part of the autostabilisation system.<ref>{{cite web |url= http://www.agustawestland.com/product/aw101-0#avionics |title= AW101: Avionics |publisher= AgustaWestland |access-date= 6 January 2012 |url-status= dead |archive-url= https://web.archive.org/web/20120119092621/http://www.agustawestland.com/product/aw101-0#avionics |archive-date= 19 January 2012 |df= dmy-all}}</ref> For safety, the aircraft is equipped with obstacle and [[Engineering:Terrain awareness and warning system|terrain avoidance]] warning systems, [[Engineering:Traffic collision avoidance system|traffic collision avoidance system]] (TCAS), and both voice and flight data recorders.<ref name="avionics today" />

The AW101 is equipped with the Blue Kestrel [[Engineering:Radar configurations and types#Search|search and detection]] radar which is capable of 360 degree scanning and can detect small targets as far as 25 [[Nautical mile|nautical mile]]s.<ref name="craw" /><ref>Friedman 1997, p. 202.</ref> As part of the Royal Navy's Merlin HM2 upgrade program, Lockheed Martin implemented a series of improvements to the radar, notably allowing it to track 40 times the number of targets previously capable.<ref>{{cite web |url= http://www.defenseindustrydaily.com/2-bn-for-british-eh101-merlin-multirole-upgrades-01745/ |title= $2 Bn for British EH101 Merlin Multi-Role Upgrades |publisher= Defense Industry Daily |date= 19 April 2011 |access-date= 5 January 2012 |archive-url= https://web.archive.org/web/20111018183113/http://www.defenseindustrydaily.com/2-bn-for-british-eh101-merlin-multirole-upgrades-01745/ |archive-date= 18 October 2011 |url-status= live}}</ref> Danish EH101s are fitted with the RDR-1600 search and [[Earth:Weather radar|weather radar]].<ref name="avionics today" /> Mk 2 Royal Navy Merlins are equipped with the AQS901 anti-submarine system for processing sonographic data from sonobuoys to detect and target submerged submarines. The AQS901 was derived from the system on the earlier [[Engineering:Hawker Siddeley Nimrod|Hawker Siddeley Nimrod]] maritime patrol aircraft.<ref>Lavington 2011, p. 428.</ref>

===Crew and cargo===
[[File:EH101 interno.jpg|thumb|right|The ramp and interior of an AW101]]
The AW101 is typically operated by a crew of three: a pilot, an observer, and a crewman/operator. The pilot is able to fly for the majority of a mission in a hands-off mode, enabled by the sophisticated autopilot. All crew members have individual access to management computers and tactical information.<ref name="evans 23">Evans 2004, p. 23.</ref>

The fuselage has a volume of {{convert|31.91|m3}} and the cargo compartment is {{convert|6.5|m}} in length, {{convert|2.3|m}} wide and {{convert|1.91|m}} high. The military version of the AW101 can accommodate up to 24 seated or 45 standing combat troops and their equipment. Alternative loads include a medical team and 16 stretchers, and cargo pallets.<ref>{{cite news |url= http://www.accessmylibrary.com/article-1G1-120758861/lockheed-martin-teams-european.html |title= Lockheed Martin teams with European firm to market new All-Weather Helicopter |quote= As a transport, the EH-101 could be configured to carry 24 to 30 troops, up to five tons of cargo or up to 16 stretchers to carry wounded |date= 1 November 2001 |last= Cox |first= Bob |work= Fort Worth Star}}</ref><ref>AgustaWestland 2008, pp.&nbsp;2–3.</ref>

The ramp, {{convert|1.91|x|2.3|m}}, can take a {{convert|3050|kg|adj=on}} load, allowing it to carry vehicles such as [[Company:Land Rover|Land Rover]]s.<ref>{{cite web |url= http://www.highbeam.com/doc/1G1-20392066.html |archive-url= https://web.archive.org/web/20130602134215/http://www.highbeam.com/doc/1G1-20392066.html |url-status= dead |archive-date= 2 June 2013 |title= Aluminum-lithium alloys in helicopters |date= 1 October 1997 |last= Smith |first= Alan F |publisher= Advanced Materials & Processes}}</ref> The ramp and cabin floor are fitted with flush tie-down points. A cargo hook under the fuselage can carry external loads of {{convert|5440|kg}} via the use of a semi-automatic cargo release unit (SACRU).<ref>{{cite web |url= http://www.onboardsystems.com/case_studies.php?id=15 |title= Heavy Lift Cargo Hook |publisher= onboardsystems.com |access-date= 28 January 2012 |archive-url= https://web.archive.org/web/20130524025812/http://www.onboardsystems.com/case_studies.php?id=15 |archive-date= 24 May 2013 |url-status= dead}}</ref> A rescue hoist and a hover trim controller are fitted at the cargo door. An optional cargo winch can be installed near to the rear ramp.<ref name="4 aug" /><ref>{{cite web |url= http://www.flightglobal.com/articles/2003/12/09/174779/sea-change.html |title= Sea change |date= 9 December 2003 |last= Scott |first= Richard |work =Flight International}}</ref>

==Operational history==

===Royal Navy===
[[File:Royal Navy Melin Mk 2 Helicopters on HMS Illustrious MOD 45157435.jpg|thumb|Merlin HM2 on HMS ''Illustrious'']]
[[File:Royal Navy Merlin HM2 Crowsnest ASaC.jpg|thumb|A Merlin HM2 fitted with Crowsnest]]
[[File:845 Commando Helicopter Force Merlin MOD 45167373.jpg |thumb|Merlin HC4 of 845 NAS off the BVI, 2020]]
The British Royal Navy's final order was for 44 ASW aircraft, originally designated ''Merlin HAS.1'' (Helicopter, Anti-Submarine Mark 1) but soon changed to ''Merlin HM1'' (Helicopter, Maritime Mark 1). The first fully operational Merlin was delivered on 17 May 1997, entering service on 2 June 2000. All aircraft were delivered by the end of 2002, and are operated by 3 Fleet Air Arm squadrons: 814 NAS, 820 NAS, 824 NAS and 829 NAS (now disbanded and merged with 814 NAS), all based at RNAS Culdrose in Cornwall. 700 NAS was the Merlin Operational Evaluation Unit from 2000 to 2008.<ref name="rn-nas">{{cite web|url=http://www.royalnavy.mod.uk/The-Fleet/Aircraft/Helicopters/Merlin-MK1 |title=Merlin MK1 |publisher=Royal Navy |access-date=5 January 2012 |url-status=dead |archive-url=https://web.archive.org/web/20111231205619/http://www.royalnavy.mod.uk/The-Fleet/Aircraft/Helicopters/Merlin-MK1 |archive-date=31 December 2011}}</ref> In March 2004, Navy Merlins were temporarily grounded following an incident at RNAS Culdrose in which a tail rotor failed due to a manufacturing defect.<ref>{{cite news |url= http://news.bbc.co.uk/1/hi/england/cornwall/3584851.stm |title= Probe continues into Merlin crash |work= BBC News |date= 31 March 2004 |access-date= 21 November 2006 |archive-url= https://web.archive.org/web/20040621192339/http://news.bbc.co.uk/1/hi/england/cornwall/3584851.stm |archive-date= 21 June 2004 |url-status= live}}</ref> An improved tail rotor was designed and adopted on most AW101s which significantly reduced associated maintenance.<ref>"New Helicopter Blades are a Pilot's Dream." ''Ottawa Citizen'', 21 July 2012.</ref>

In 1995, it was announced that the Navy's [[Engineering:Westland Lynx|Westland Lynx]] helicopters would be retired in favour of an all-Merlin fleet.<ref>{{cite journal |title= The Maritime helicopter |first= Richard |last= Cobbold |journal= Chief of the Defence Staff |volume= 139 |issue= 2 |date= April 1994 |pages= 56–63 |doi=10.1080/03071849408445805}}</ref> However, the subsequent Strategic Defence and Security Review 2010 stated that the future naval helicopters would be the Merlin and the Wildcat, a derivative of the Lynx.<ref>{{Cite web |url=http://www.direct.gov.uk/prod_consum_dg/groups/dg_digitalassets/@dg/@en/documents/digitalasset/dg_191634.pdf |archive-url=https://web.archive.org/web/20101222022127/http://www.direct.gov.uk/prod_consum_dg/groups/dg_digitalassets/%40dg/%40en/documents/digitalasset/dg_191634.pdf |url-status=dead |title=page 21 |archive-date=22 December 2010}}</ref> Royal Navy Merlins have seen action in the Caribbean, on counter-narcotics and hurricane support duties, as well as maritime security duties in the Persian Gulf. Merlins have also seen active duty in Iraq, providing support to British and coalition forces based in the region.<ref>{{cite news |title= Merlin HM1 Helicopter On The 'Front Line' For 10 Years |publisher= HM Forces |date= 3 October 2011}}</ref>

The Merlin HM1 has been cleared to operate from the Royal Navy's [[Engineering:Aircraft carrier|aircraft carrier]]s, amphibious assault ships, Type 23 frigates, [[Engineering:Type 45 destroyer|Type 45 destroyer]] and several Royal Fleet Auxiliary (RFA) vessels including the {{sclass-|Fort Victoria|replenishment oiler|4}}. 30 aircraft have been upgraded to ''Merlin HM2'' standard under the £750m Merlin Capability Sustainment Programme; Lockheed Martin UK delivered the final HM2 on 11 July 2016.<ref name="Osborne20140716">{{cite web |url=http://aviationweek.com/farnborough-2014/uk-considering-bringing-orphaned-merlins-service |title=U.K. Considering Bringing Orphaned Merlins Into Service |date=15 July 2014 |first=Tony |last=Osborne |access-date=16 July 2014 |archive-url=https://web.archive.org/web/20140729020513/http://aviationweek.com/farnborough-2014/uk-considering-bringing-orphaned-merlins-service |archive-date=29 July 2014 |url-status=live}}</ref><ref name="LockheedMartincompletesMerlinHM2deliveries">{{cite web |url=http://www.janes.com/article/62382/lockheed-martin-completes-merlin-hm2-deliveries? |title=Lockheed Martin completes Merlin HM2 deliveries |date=19 July 2016 |first=Richard |last=Scott |publisher=IHS Jane's 360 |access-date=20 July 2016 |archive-url=https://web.archive.org/web/20160720174512/http://www.janes.com/article/62382/lockheed-martin-completes-merlin-hm2-deliveries |archive-date=20 July 2016 |url-status=live}}</ref> The HM2 has a new mission system, digital cockpit, electro-optical camera and multi-static sonar processing.<ref name="Osborne20120928">{{cite news|url=http://www.shephardmedia.com/news/rotorhub/merlin-mk2-puts-sea-first-time/ |title=Merlin Mk2 puts to sea for the first time |date=28 September 2012 |first=Tony |last=Osborne |publisher=Shephard Media |url-status=dead |archive-url=https://web.archive.org/web/20121016033540/http://www.shephardmedia.com/news/rotorhub/merlin-mk2-puts-sea-first-time/ |archive-date=16 October 2012}}</ref> The HM2 achieved IOC on 30 June 2014 after flying 480 hours from ''Illustrious'' during Exercise Deep Blue earlier that month. It was also reported that some of the eight airframes not scheduled to be upgraded for financial reasons may be updated.<ref name="Osborne20140716" /><ref name="janes 14">Jane's Defence Weekly, 8 July 2009. p. 14.</ref> Five HM2s are in maintenance at a time, leaving 25 available, of which 14 will be assigned to the {{sclass-|Queen Elizabeth|aircraft carrier|1}}.<ref name="Osborne20140716" />

In addition to its ASW role, the HM2 will be able to carry an airborne early warning (AEW) pod known as the Crowsnest, replacing the [[Engineering:Westland Sea King|Sea King ASaC7]].<ref name="ASaC7 replace">{{cite web |url= https://www.flightglobal.com/news/articles/uks-crowsnest-surveillance-programme-takes-off-433245/ |title= UK's Crowsnest surveillance programme takes off |work= Flight International |date= 17 January 2017 |archive-url= https://web.archive.org/web/20190406001755/https://www.flightglobal.com/news/articles/uks-crowsnest-surveillance-programme-takes-off-433245/ |archive-date= 6 April 2019 |url-status= live}}</ref> In September 2011, Thales UK proposed re-using Sea King ASaC7 equipment, such as the Searchwater 2000, on the Merlin; Lockheed Martin has proposed developing a new multi-functional sensor for both the AW101 and other aircraft.<ref>{{cite web |first= Craig |last= Hoyle |url= http://www.flightglobal.com/news/articles/dsei-thales-outlines-sea-king-7-replacement-proposal-362116/ |title= Thales outlines Sea King 7 replacement proposal |work= Flight International |date= 15 September 2011 |archive-url= https://web.archive.org/web/20111211012450/http://www.flightglobal.com/news/articles/dsei-thales-outlines-sea-king-7-replacement-proposal-362116/ |archive-date= 11 December 2011 |url-status= live}}</ref> Lockheed originally planned to use a derivative of the F-35's APG-81 radar; however, a rival Elta system and the Thales system both commenced flight trials in 2014.<ref name="Osborne20140716" /><ref name="Scott20140507">{{cite news |url=http://www.janes.com/article/37615/uk-extends-sea-king-asac-7-life-out-to-2018 |title=UK extends Sea King ASaC.7 life out to 2018 |first=Richard |last=Scott |newspaper=IHS Jane's Defence Weekly |date=7 May 2014 |archive-url=https://web.archive.org/web/20140529145845/http://www.janes.com/article/37615/uk-extends-sea-king-asac-7-life-out-to-2018 |archive-date=29 May 2014 |url-status=live}}</ref> However, revised plans will see Crowsnest achieve initial operating capability in September 2021 and full operating capability in May 2023.<ref>Minstry of Defense, (26 June 2020)[https://www.nao.org.uk/wp-content/uploads/2020/06/007678-001-Carrier-Strike-preparing-for-deployment.pdf Carrier Strike – Preparing for deployment], retrieved 4 January 2021</ref> On 22 May 2015, the MOD and prime contractor Lockheed Martin UK selected Thales to provide the radar and mission system for the Crowsnest.<ref>{{cite web|url=https://www.gov.uk/government/news/new-surveillance-system-for-future-royal-navy-aircraft-carriers-revealed|title=New surveillance system for future Royal Navy aircraft carriers revealed|work=gov.uk|archive-url=https://web.archive.org/web/20150717211148/https://www.gov.uk/government/news/new-surveillance-system-for-future-royal-navy-aircraft-carriers-revealed|archive-date=17 July 2015|url-status=live}}</ref>

On 15 December 2009, plans were announced to transfer RAF Merlin HC3s and HC3As to the Royal Navy's Commando Helicopter Force to replace retiring Sea King HC4 helicopters.<ref name="Ships_aircraft_axed" /> The Sea King was set to retire in 2016, leaving the Navy operating a combination of the Wildcat and Merlin.<ref name="Ships_aircraft_axed">{{cite web|title=Ships and aircraft axed to pay for war against Taleban |publisher=Navy News |date=16 December 2009 |url=http://www.navynews.co.uk/news/647-ships-and-aircraft-axed-to-pay-for-war-against-taleban.aspx |url-status=dead |archive-url=https://web.archive.org/web/20110611061927/http://www.navynews.co.uk/news/647-ships-and-aircraft-axed-to-pay-for-war-against-taleban.aspx |archive-date=11 June 2011}}</ref> 846 NAS reformed with ex-RAF Merlin HC3s on 30 September 2014;<ref>{{cite web |title= Navy takes delivery of Merlin fleet |publisher= Navy News |date= 1 October 2014 |url= https://navynews.co.uk/archive/news/item/11515 |access-date= 1 November 2014 |archive-url= https://web.archive.org/web/20141006085829/https://navynews.co.uk/archive/news/item/11515 |archive-date= 6 October 2014 |url-status= live}}</ref> 845 NAS followed on 9 July 2015.<ref>{{cite web |title= 845 thrive as famous naval squadron takes charge of battlefield Merlins |publisher= Royal News |date= 10 July 2015 |url= http://www.royalnavy.mod.uk/news-and-latest-activity/news/2015/july/10/150710-845-merlin |access-date= 16 August 2015 |archive-url= https://web.archive.org/web/20150712162159/http://www.royalnavy.mod.uk/news-and-latest-activity/news/2015/july/10/150710-845-merlin |archive-date= 12 July 2015 |url-status= live}}</ref> On 25 May 2018, the first of 25 converted Royal Marines Commando Merlin Mk4/4A were delivered to Royal Naval Air Station (RNAS) Yeovilton.<ref>{{cite web|url=http://www.janes.com/article/80290/royal-navy-receives-first-commando-merlin|title=Royal Navy receives first Commando Merlin – Jane's 360|website=www.janes.com|access-date=28 May 2018|archive-url=https://web.archive.org/web/20180527080411/http://www.janes.com/article/80290/royal-navy-receives-first-commando-merlin|archive-date=27 May 2018|url-status=live}}</ref><ref>{{cite web|url=https://www.royalnavy.mod.uk/news-and-latest-activity/news/2018/may/25/180525-defence-minister-welcomes-first-of-new-carrier-ready-helicopter-fleet|title=Defence minister welcomes first of new carrier-ready helicopter fleet – Royal Navy |website= royalnavy.mod.uk|access-date=28 May 2018|archive-url=https://web.archive.org/web/20180529203155/https://www.royalnavy.mod.uk/news-and-latest-activity/news/2018/may/25/180525-defence-minister-welcomes-first-of-new-carrier-ready-helicopter-fleet|archive-date=29 May 2018|url-status=live}}</ref> In July 2020, the Merlin HM2 and HC4/4A helicopters were planned to be in service until 2029 and 2030, respectively.<ref>{{Cite web|last=Quin|first=Jeremy|date=7 July 2020|title=Merlin Helicopters:Written question - 65947|url=https://www.parliament.uk/business/publications/written-questions-answers-statements/written-question/Commons/2020-06-29/65947|access-date=8 July 2020|website=UK Parliament|language=en}}</ref> On 11 June 2021, it was confirmed that their Out of Service Date (OSD) had been moved to 2040.<ref>{{Cite web|url=https://www.flightglobal.com/helicopters/uk-extends-merlin-operations-until-2040/144123.article#.YMNwX-04Hks.twitter|title = UK extends Merlin operations until 2040}}</ref>

===Royal Air Force===
[[File:British Provincial Reconstruction Team Visit Al Fao, Iraq.jpg|thumb|upright|Merlin HC3 in Iraq, 2008]]

The RAF ordered 22 Merlin HC3 for transport missions, the first of which entered service in January 2001 with No. 28 Squadron RAF based at RAF Benson. The type is equipped with extended-range fuel tanks and is capable of air-to-air refuelling. The Merlin is frequently utilised for troop transport duties and for the transport of bulky objects, either internally or [[Biology:Glossary of wildfire terms#S|underslung]], including vehicles and artillery.<ref name="RAF HC3">{{cite web |url= http://www.raf.mod.uk/equipment/merlin.cfm |archive-url= https://web.archive.org/web/20070223100716/http://www.raf.mod.uk/equipment/merlin.cfm |url-status= dead |archive-date= 23 February 2007 |title= Merlin HC3 |publisher= Royal Air Force |access-date= 16 January 2012}}</ref> The Merlin Depth Maintenance Facility at RNAS Culdrose performed most tasks upon the Merlin HC3.<ref>{{cite web|url=http://www.serco.com/markets/defence/imos.asp |title=Integrated Merlin Operational Support |publisher=Serco |access-date=5 February 2010 |archive-url=https://web.archive.org/web/20100408130944/http://www.serco.com/markets/defence/imos.asp |archive-date=8 April 2010 |url-status=dead}}</ref>

The Merlin's first operational deployment was to the [[Place:Balkans|Balkans]] region in 2003.<ref>{{cite web |url= http://www.raf.mod.uk/rafbenson/aboutus/merlinhc3.cfm |title= Merlin HC3 |publisher= Royal Air Force |access-date= 5 January 2012 |archive-url= https://web.archive.org/web/20111207054158/http://www.raf.mod.uk/RAFbenson/aboutus/merlinhc3.cfm |archive-date= 7 December 2011 |url-status= live}}</ref> RAF Merlins were first deployed to Iraq as part of Operation Telic in 2004, supporting coalition forces and were operated as the main medevac asset in southern Iraq; both Flight Lieutenant Kev Harris and Flight Lieutenant Michelle Goodman were awarded the DFC during this period.<ref>{{cite web|url=http://www.raf.mod.uk/rafbenson/newsweather/index.cfm?storyid=33B396E9-1143-EC82-2E1E6E8AD78F3871|title=Top Operational Honour for Pilot|work=mod.uk|access-date=23 July 2015|archive-url=https://web.archive.org/web/20150723180836/http://www.raf.mod.uk/rafbenson/newsweather/index.cfm?storyid=33B396E9-1143-EC82-2E1E6E8AD78F3871|archive-date=23 July 2015|url-status=live}}</ref> Merlins routinely operated around [[Place:Basra|Basra]] until Britain's withdrawal in June 2009.<ref>{{cite web |url= http://www.rin.org.uk/news.aspx?ID=267&SectionID=2 |title= Merlin Helicopter Operations in Iraq by Wing Commander Jeff Lindsay |publisher= Royal Institute of Navigation |date= 1 December 2011 |access-date= 5 January 2012 |archive-url= https://web.archive.org/web/20120406075303/http://www.rin.org.uk/news.aspx?ID=267&SectionID=2 |archive-date= 6 April 2012 |url-status= dead |df= dmy-all}}</ref>

In 2002, Westland made an unsuccessful unsolicited offer to the British Ministry of Defence, proposing an enhanced Merlin variant intended to satisfy the demand for additional lift capacity.<ref>{{cite journal |title= Westland pushes additional Merlins for U.K. lift needs |first= D |last= Barrie |journal= Aviation Week & Space Technology |volume= 157 |date= 23 December 2002 |page= 29 |issue= 26}}</ref> An alternative measure was the acquisition of six AW101s from Denmark in 2007; designated ''Merlin HC3A'', these were assigned to the RAF, allowing Merlins to be deployed in Afghanistan.<ref>{{cite magazine |first= Bill |last= Burchell |title= U.K. Puma Upgrade Approved |magazine= Aviation Week |date= 6 August 2009}}</ref> The HC3A is used for training and not for frontline operations due to various configuration differences.<ref name="AW20140127" /> In December 2007, a second Merlin squadron, No. 78 Squadron was formed at RAF Benson.<ref>{{cite web |url= http://www.raf.mod.uk/news/index.cfm?storyid=A64EDF95-1143-EC82-2EBC003A8CAFA24D |title= 78 Squadron Operational |publisher= Royal Air Force |date= 3 December 2007 |access-date= 10 December 2007 |archive-url= https://web.archive.org/web/20071205182732/http://www.raf.mod.uk/news/index.cfm?storyid=A64EDF95-1143-EC82-2EBC003A8CAFA24D |archive-date= 5 December 2007 |url-status= live}}</ref>

[[File:Elwood H.L.S. ( Heliport ) Barrasford - geograph.org.uk - 1587659.jpg|thumb|left|RAF Merlin HC3A, 2008]]
In 2009, five Merlin Mk3s were operating in Afghanistan, transporting troops and supplies. The deployment to Afghanistan was criticised as the aircraft reportedly lacked protective [[Chemistry:Kevlar|Kevlar]] armour.<ref>{{cite news |url= http://news.bbc.co.uk/1/hi/uk/8182649.stm |title= MoD denies Merlin 'unsafe' claims |work=BBC News |date= 4 August 2009}}</ref> By July 2010, the Merlin fleet was fully fitted with ballistic armour.<ref name="ballistic armour">{{cite web |url= http://www.flightglobal.com/articles/2010/07/22/344788/farnborough-permali-gloucester-protects-raf-merlins.html |title= Permali Gloucester protects RAF Merlins |work= Flight International |date= 22 July 2010}}</ref> The deployment of Merlins to Afghanistan allowed the detachment of Sea Kings to be withdrawn from the region in October 2011.<ref>{{cite web |first= Craig |last= Hoyle |url= http://www.flightglobal.com/news/articles/uk-withdraws-sea-king-transports-from-afghanistan-363839/ |title= UK withdraws Sea King transports from Afghanistan |work= Flight International |date= 25 October 2011 |access-date= 5 January 2012 |archive-url= https://web.archive.org/web/20111229165900/http://www.flightglobal.com/news/articles/uk-withdraws-sea-king-transports-from-afghanistan-363839/ |archive-date= 29 December 2011 |url-status= live}}</ref> As part of the UK drawdown in Afghanistan, Merlins were withdrawn from theatre in June 2013.<ref>{{cite web|last=Inglis |first=Will |url=http://www.bfbs.com/news/afghanistan/final-flight-merlins-63726.html |archive-url=https://web.archive.org/web/20130717045713/http://www.bfbs.com/news/afghanistan/final-flight-merlins-63726.html |title=Final Flight for Merlins |work=British Forces News |archive-date=17 July 2013 |url-status=dead}}</ref>

In 2012, the RAF's Merlin HC3/3A fleet began to be transferred to the Royal Navy for use by the Commando Helicopter Force. Royal Navy personnel worked alongside RAF crew at Benson to build experience during the transition.<ref>{{cite web|url=http://navynews.co.uk/archive/news/item/5111|title=Navy News – Reporting from the Fleet|work=navynews.co.uk|access-date=23 July 2015|archive-url=https://web.archive.org/web/20150723190728/https://navynews.co.uk/archive/news/item/5111|archive-date=23 July 2015|url-status=live}}</ref> The £454m Merlin Life Sustainment Programme resulted in 25 HC3/3A airframes being fitted with the cockpit electronics of the HM2, folding tails and main rotor heads, strengthened landing gear, deck lashing mounting points, obsolescence updates, fast-roping points and a common emergency egress system.<ref name="AW20140127">{{cite news |url=http://www.aviationweek.com/Article.aspx?id=/article-xml/awx_01_27_2014_p0-658249.xml |title=U.K. To Spend £454m on Merlin Modernization Program |first=Anthony |last=Osborne |date=27 January 2014 |newspaper=Aviation Week |access-date=30 May 2019 |archive-url=https://web.archive.org/web/20140203030233/http://www.aviationweek.com/Article.aspx?id=%2Farticle-xml%2Fawx_01_27_2014_p0-658249.xml |archive-date=3 February 2014 |url-status=live}}</ref> The first HC4 is to begin flight trials in September 2017, with an IOC in mid-2018;<ref name="AW20140127" /> an interim folding main rotor head will be fitted to some HC3 for shipborne operations prior to the HC4 upgrade.<ref name="AW20140127" />

Command of the UK Merlin HC3/3A fleet was formally transferred from the RAF to the Royal Navy during a ceremony at RAF Benson on 30 September 2014.  As part of the same ceremony, the RAF's 78 Sqn was disbanded and the Royal Navy's 846 Naval Air Squadron stood-up with the Merlin.<ref>{{cite news|url=https://www.bbc.co.uk/news/uk-england-oxfordshire-33474258|title=Prince Michael of Kent attends service at RAF Benson|newspaper=BBC News|access-date=23 July 2015|date=10 July 2015|archive-url=https://web.archive.org/web/20150714051326/http://www.bbc.co.uk/news/uk-england-oxfordshire-33474258|archive-date=14 July 2015|url-status=live}}</ref> The RAF's 28(AC) continued to operate as part of the Commando Helicopter Force until July 2015, when 28(AC) Sqn stood down and 845 Naval Air Squadron stood-up. 846 NAS relocated from RAF Benson to RNAS Yeovilton in March 2015, with 845 NAS following in June 2016.<ref>{{cite book|last1=Ballance|first1=Theo|title=The Squadrons and Units of the Fleet Air Arm|date=2016|publisher=Air-Britain|isbn=978-0-85130-489-2|pages=211}}</ref>

===Italian Navy===
[[File:EH101-112ASuW.jpg|thumb|left|Italian Navy airborne early warning (AEW) variant at Luni-Sarzana, 2007]]

In 1997, the Italian government ordered 16 AW101 helicopters for the Italian Navy, with options for four more. These AW101 included eight of the anti-surface/submarine (ASuW/ASW) version, four airborne early warning (AEW), four amphibious support helicopters (ASH).<ref name="difesa">{{cite web |title=EH - 101 |url=https://www.difesa.it/SGD-DNA/Staff/DT/ARMAEREO/Programmi/Ala-Rotante/Pagine/EH101.aspx |publisher=Italian Ministry of Defense |access-date=29 May 2020}}</ref> The government then exercised its option for four additional ASH helicopters, which were delivered by 2006.<ref name="difesa"/> The same year the government ordered two more AW101 ASH helicopters in a slightly modified version.<ref name="difesa"/>

The first Italian Navy production helicopter (''MM81480'') flew on 4 October 1999 and was officially presented to the press on 6 December 1999. Italy accepted delivery of the 21st AW101, configured for anti-submarine warfare, on 4 August 2009.<ref name="21 deliver">{{cite web|url=http://www.agustawestland.com/news/italian-navy-takes-delivery-its-21st-aw101-helicopter |title=Italian Navy Takes Delivery of Its 21st AW101 Helicopter |publisher=AgustaWestland |date=4 August 2009 |url-status=dead |archive-url=https://web.archive.org/web/20130605204612/http://www.agustawestland.com/news/italian-navy-takes-delivery-its-21st-aw101-helicopter |archive-date=5 June 2013}}</ref> In total 22 AW101 helicopters have been delivered to the Italian Navy.<ref name="difesa"/> 

Italian AW101s have operated from a variety of ships and have seen service overseas; in 2009 the Italian Navy used its AW101 fleet as executive transports for visiting heads of state and officials during the 35th G8 summit.<ref name="21 deliver" /> In 2010, the Italian Navy deployed three AW101s to Afghanistan, where they were flown in both the transport and utility roles.<ref>{{cite web|last=Peruzzi|first=Luca|title=Italian Navy deploys first AW101s to Afghanistan|url=http://www.flightglobal.com/news/articles/picture-italian-navy-deploys-first-aw101s-to-afghanistan-349607/|work=Flight International|access-date=4 January 2011|date=15 November 2010|archive-url=https://web.archive.org/web/20120308213001/http://www.flightglobal.com/news/articles/picture-italian-navy-deploys-first-aw101s-to-afghanistan-349607/|archive-date=8 March 2012|url-status=live}}</ref> In 2011, it was reported that the Italian contingent in Afghanistan, consisting of AW101s, had been providing coverage of a wide area of the country.<ref>{{cite web |url= http://www.defenseindustrydaily.com/Allies-Absent-in-Afghanistan-Helicopters-Hired-05366/ |title= Allies Absent in Afghanistan – Helicopters Hired |publisher= Defense Industry Daily |date= 7 November 2011 |access-date= 5 January 2012 |archive-url= https://web.archive.org/web/20120204013727/http://www.defenseindustrydaily.com/Allies-Absent-in-Afghanistan-Helicopters-Hired-05366/ |archive-date= 4 February 2012 |url-status= live}}</ref>

===Italian Air Force===
In June 2011 the AW101 was chosen by the {{wipe|Italian Air Force}} to replace its ageing Sea King HH-3F helicopters in the combat search and rescue role. A total of 15 helicopters in the HH-101A variant were ordered and delivered between 2016 and 2020.<ref>{{cite web |title=First Italian Air Force HH-101A "CAESAR" enters service |url=https://www.leonardocompany.com/en/press-release-detail/-/detail/hh101a |publisher=Leonardo |access-date=29 May 2020}}</ref><ref>{{cite web|last=Peruzzi|first=Luca|title=Italian air force chief details Libyan operations|url=http://www.flightglobal.com/news/articles/italian-air-force-chief-details-libyan-operations-358044/|work=Flight International|access-date=4 January 2012|date=17 June 2011|archive-url=https://web.archive.org/web/20111220172511/http://www.flightglobal.com/news/articles/italian-air-force-chief-details-libyan-operations-358044/|archive-date=20 December 2011|url-status=live}}</ref>

===Royal Canadian Air Force===
{{main|Engineering:AgustaWestland CH-149 Cormorant}}
[[File:Canada Search and Rescue.jpg|thumb|RCAF CH-149 Cormorant alongside a Canadian Coast Guard cutter]]

In 1997, in light of the declining condition of its helicopter fleet, Canada launched the Canadian Search and Rescue Helicopter competition. It was won by the EH101, which was designated ''CH-149 Cormorant'' in Canadian service.<ref name="plam 152">Plamondon 2009, pp.&nbsp;151–152.</ref>

In 2004, the EH101 was entered into a Canadian competition to replace the shipboard Sea King fleet, but the [[Engineering:Sikorsky CH-148 Cyclone|Sikorsky CH-148 Cyclone]] was selected.<ref>Plamondon 2009, pp.&nbsp;184–186.</ref> In 2013, following difficulties with the CH-148 procurement,<ref>{{cite news|title='Other options' sought for Sea King helicopter replacements|url=http://www.cbc.ca/news/politics/story/2013/09/05/pol-sikorsky-cyclone-helicopters-sea-kings-contract-public-works.html|access-date=6 September 2013|newspaper=CBC.CA|date=5 September 2013|archive-url=https://web.archive.org/web/20130906022644/http://www.cbc.ca/news/politics/story/2013/09/05/pol-sikorsky-cyclone-helicopters-sea-kings-contract-public-works.html|archive-date=6 September 2013|url-status=live}}</ref> the {{wipe|Royal Canadian Air Force}} (RCAF) was reported to be seriously considering cancelling the contract with Sikorsky and was investigating the possibility of procuring the AW101 instead.<ref>{{cite news|last=Chase|first=Steven|title=Helicopter purchase's fate in doubt as Ottawa examines other models|url=https://www.theglobeandmail.com/news/politics/helicopter-purchases-fate-in-doubt-as-ottawa-examines-other-models/article14155484/|access-date=6 September 2013|newspaper=The Globe and Mail|date=5 September 2013|archive-url=https://web.archive.org/web/20130907064730/http://www.theglobeandmail.com/news/politics/helicopter-purchases-fate-in-doubt-as-ottawa-examines-other-models/article14155484/|archive-date=7 September 2013|url-status=live}}</ref> However, an initial batch of six Cyclones was delivered to the RCAF in June 2015.<ref>{{cite web|url=http://www.cbc.ca/news/canada/nova-scotia/ch-148-cyclones-delivered-to-halifax-airbase-1.3119737|title=CH-148 Cyclones delivered to Halifax airbase|date=19 June 2015|work=cbc.ca|access-date=22 September 2015|archive-url=https://web.archive.org/web/20150924180727/http://www.cbc.ca/news/canada/nova-scotia/ch-148-cyclones-delivered-to-halifax-airbase-1.3119737|archive-date=24 September 2015|url-status=live}}</ref>

===Royal Danish Air Force===
In 2001, the {{wipe|Royal Danish Air Force}} (RDAF) announced the purchase of eight EH101s for SAR duties and six tactical troop transports for 722 Squadron.<ref>{{cite web |url= http://www.alacrastore.com/storecontent/Business-and-Industry/24995790 |title= AgustaWestland received a UKPd250 mil contract to supply 14 helicopters to Denmark |publisher= The Engineer |date= 21 September 2001 |access-date= 6 February 2010 |archive-url= https://web.archive.org/web/20130624015026/http://www.alacrastore.com/storecontent/Business-and-Industry/24995790 |archive-date= 24 June 2013 |url-status= live}}</ref> The last of the 14 AW101s was delivered in March 2007 and the first SAR AW101s became operational out of Karup Airport in April 2007. In 2007, the six troop transport AW101s were transferred to the British MOD; in exchange, the British government ordered six new-build AW101s as replacements for the RDAF.<ref name="danish special">{{cite web |first= Craig |last= Hoyle |url= http://www.flightglobal.com/news/articles/nordic-special-great-danes-211082/ |title= Nordic special: Great Danes |work= Flight International |date= 12 December 2006 |access-date= 6 January 2012 |archive-url= https://web.archive.org/web/20120308215202/http://www.flightglobal.com/news/articles/nordic-special-great-danes-211082/ |archive-date= 8 March 2012 |url-status= live}}</ref>

[[File:Danish air force EH-101 Merlin.jpg|thumb|RDAF AW101, 2007]]
Danish AW101s have a higher gross weight capacity of 15,600&nbsp;kg and were, as delivered, coated in a paint designed to reduce the aircraft's [[Physics:Infrared signature|infrared signature]]. In the SAR role, RDAF AW101s have a crew of six and were initially painted yellow to distinguish themselves from AW101 allocated to military duties,<ref name="danish special" /> but were later painted green, and all 14 AW101s are used for SAR and troop transport.<ref name="dane aviaweek" /><ref name="rdaf101">"[http://forsvaret.dk/FTK/omflyvev%C3%A5bnet/Factsheets/Documents/EH101.pdf EH-101 Merlin] {{webarchive |url=https://web.archive.org/web/20131221095104/http://forsvaret.dk/FTK/omflyvev%C3%A5bnet/Factsheets/Documents/EH101.pdf |date=21 December 2013}}" ''{{wipe|Royal Danish Air Force}}''. Accessed: 19 December 2013.</ref>

On 28 January 2008, the drive shaft of a Danish AW101 broke, leading to an emergency landing at Billund Airport. Following the incident, the Danish fleet was grounded as a precaution and the AW101's future was publicly debated.<ref>{{cite web |url= http://www.berlingske.dk/article/20080204/danmark/702040040/ |title= Forsvarets fejlindkøb står i kø |work= Berlingske Tidende |date= 4 February 2008 |access-date= 5 February 2008 |archive-url= https://web.archive.org/web/20080207065457/http://www.berlingske.dk/article/20080204/danmark/702040040/ |archive-date= 7 February 2008 |url-status= live}}</ref> In the first six months of 2008, the RDAF reported an operational availability of roughly 50%, well below the target of 80%, partly due to an inadequate maintenance organisation and staff shortages.<ref>{{cite web |url= http://www.rigsrevisionen.dk/media(705,1033)/EH-101_helicopters.pdf |title= Extract from the report to the Public Accounts Committee on the Danish Defence's EH-101 helicopters |publisher= Rigsrevisionen |date= September 2008}} {{dead link|date=April 2014}}</ref>

In January 2011, the Danish Ministry of Defence reportedly could not afford the retrofitting of the AW101 fleet for Afghanistan operations, against earlier reports of a deployment in 2012.<ref>{{cite web |url= http://www.b.dk/danmark/danske-soldater-faar-helikoptere-sent |title= Danske soldater får helikoptere for sent |work= Berlingske Tidende |date= 3 January 2011 |access-date= 11 January 2012 |archive-url= https://web.archive.org/web/20150923231441/http://www.b.dk/danmark/danske-soldater-faar-helikoptere-sent |archive-date= 23 September 2015 |url-status= live}}</ref><ref>{{cite web |url= https://translate.google.com/translate?hl=en&sl=da&tl=en&u=http%3A%2F%2Fwww.b.dk%2Fnationalt%2Fingen-helikopter-til-udsendte-soldater |title= Ingen helikopter til udsendte soldater |work= Berlingske Tidende |date= 25 October 2011 |access-date= 12 November 2016 |archive-url= https://web.archive.org/web/20160106194119/http://translate.google.com/translate?hl=en&sl=da&tl=en&u=http%3A%2F%2Fwww.b.dk%2Fnationalt%2Fingen-helikopter-til-udsendte-soldater |archive-date= 6 January 2016 |url-status= live}}</ref> In February 2013, Aviation Week reported that earlier reliability problems had been resolved and that a full upgrade package would be applied to Danish AW101s; these included the addition of [[Social:Electronic warfare|electronic warfare]] pods and a new electro-optical system, in advance of a deployment in Afghanistan in 2014.<ref name="dane aviaweek">{{cite magazine |first= Anthony |last= Osborne |url= http://www.aviationweek.com/Article.aspx?id=/article-xml/asd_02_04_2013_p03-01-544143.xml |title= Denmark Plans AW101 Deployment To Afghanistan |magazine= Aviation Week |date= 4 February 2013 |access-date= 30 May 2019 |archive-url= https://web.archive.org/web/20130602134649/http://www.aviationweek.com/Article.aspx?id=%2Farticle-xml%2Fasd_02_04_2013_p03-01-544143.xml |archive-date= 2 June 2013 |url-status= live}}</ref> In September 2013, Danish AW101s were to receive L-3 [[Company:Wescam|Wescam]] MX-15 electro-optical/infrared (EO/IR) sensors; SAR aircraft already carry the FLIR Systems Star Safire II EO/IR sensor.<ref>{{cite web |first=Craig |last=Hoyle |title=Danish AW101s to get MX-15 sensor fit |date=2 September 2013 |url=http://www.flightglobal.com/news/articles/danish-aw101s-to-get-mx-15-sensor-fit-390092/ |publisher=Flight International |access-date=7 September 2013 |archive-url=https://web.archive.org/web/20130927051908/http://www.flightglobal.com/news/articles/danish-aw101s-to-get-mx-15-sensor-fit-390092/ |archive-date=27 September 2013 |url-status=live}}</ref>

===Royal Norwegian Air Force===
[[File:AgustaWestland AW101 Mk.612 ‘ZZ102 0265’ (27591516877).jpg|thumb|A Norwegian Leonardo AW101 SAR Queen helicopter, 2017]]

On 25 October 2007, a project started that had the intent to replace all [[Engineering:Westland Sea King|Westland Sea King]] search and rescue helicopters with new rescue helicopters by 2020. On 19 December 2013, a contract was signed between AgustaWestland and the government, for the purchase of 16 AW101 helicopters. The agreement came about after fierce competition between different manufacturers to satisfy the Norwegian requirements. Participants were AgustaWestland, Eurocopter, NHIndustries, Sikorsky Aircraft Corporation and Boeing. The government considered that AgustaWestland AW101 met the requirements and specifications in the best possible way.<ref>[https://www.regjeringen.no/nb/aktuelt/agustawestland-til-sluttforhandlinger-om/id745358/ AgustaWestland til sluttforhandlinger om nye redningshelikoptre] (Government of Norway, official site) {{in lang|no}}</ref>

On 12 June 2017, Per-Willy Amundsen, Minister of Justice and Public Security, announced the opening of Leonardo's AW101 Norway Training Centre at Stavanger Sola Air Station. The training centre includes an AW101 Full Flight Simulator (FFS), jointly developed by Leonardo and CAE to Level D, which is a CAE Series 3000 device, along with an AW101 SAR console training system linked to the FFS to provide rear crew training. The first training course at the centre started prior to delivery of the first rotorcraft. The training center will be used by both Norwegian and foreign AW101 customers.<ref>{{Cite web|url=http://www.leonardocompany.com/en/-/training-centre-norvegia-aw101|title=Leonardo's AW101 Norway training centre opens|date=13 June 2017|website=Leonardocompany.com|archive-url=https://web.archive.org/web/20170619161836/http://www.leonardocompany.com/en/-/training-centre-norvegia-aw101|archive-date=19 June 2017|url-status=live}}</ref>

The first AW101 was delivered in November 2017.<ref name="NorwayFirstFG">{{cite web|last1=Perry|first1=Dominic|title=Norway takes first SAR-roled AW101|url=https://www.flightglobal.com/news/articles/norway-takes-first-sar-roled-aw101-443463/|website=Flight Global|access-date=20 November 2017|archive-url=https://archive.today/20171120200820/https://www.flightglobal.com/news/articles/norway-takes-first-sar-roled-aw101-443463/|archive-date=20 November 2017|date=20 November 2017|url-status=dead}}</ref><ref name="NowayFirstJanes">{{cite web|last1=Jennings|first1=Gareth|title=Norway receives first AW101 SAR helicopter|url=http://www.janes.com/article/75810|website=IHS Jane's 360|access-date=20 November 2017|archive-url=https://archive.today/20171120200853/http://www.janes.com/article/75810/norway-receives-first-aw101-sar-helicopter|archive-date=20 November 2017|date=19 November 2017|url-status=dead}}</ref> The Norwegian AW101s officially started operating in the rescue role on 1 September 2020.<ref>{{Cite web|url=https://www.tu.no/artikler/en-tesla-eller-playstation-5-med-rotorer-redningstjenesten-forsoker-a-forklare-hva-sar-queen-betyr/498438|title=En Tesla eller Playstation 5 med rotorer? Redningstjenesten forsøker å forklare hva Sar Queen betyr|first1=Per Erlien|last1=Dalløkken|first2=Eirik Helland|last2=Urke|date=2 September 2020|website=Tu.no}}</ref> The Sea Kings will be phased out gradually until the middle of 2023, after 47 years of service.<ref>{{Cite web|url=https://www.thenorwegianstandard.com/article/norway-to-start-operating-world-s-best-rescue-helicopters-on-tuesday/1014|title=Norway to start operating "world's best" rescue helicopters on Tuesday|date=27 August 2020|website=The Norwegian Standard}}</ref> The AW101 is named ''SAR Queen'' in Norwegian service.<ref>{{Cite web|url=https://www.tu.no/artikler/overtar-for-sea-king-i-dag-nytt-redningshelikopter-har-fatt-nytt-navn/498387|title=Overtar for Sea King: Nytt redningshelikopter har fått nytt navn|first=Per Erlien|last=Dalløkken|date=1 September 2020|website=Tu.no}}</ref>

===Portuguese Air Force===
[[File:Portuguese Air Force EH-101 Merlin.jpg|thumb|Portuguese Air Force Merlin, 2007]]

The {{wipe|Portuguese Air Force}} had purchased 12 Merlins under a €446 million contract, the first of which was delivered on 22 December 2004. The type has been used to conduct transport, search and rescue, and maritime surveillance missions, progressively replacing the Aérospatiale Puma previously tasked with these missions.<ref>Harding ''Air International'' July 2010, pp. 70–72.</ref> The main role of Portuguese AW101s is to perform search and rescue missions within Portugal's maritime zone. They are operated by 751 Squadron and are kept on constant alert at three bases: Montijo near [[Place:Lisbon|Lisbon]], Lajes Field on the Azores, and Porto Santo Island.<ref>{{cite web|url=http://www.agustawestland.com/news/portuguese-air-forces-aw101-fleet-achieves-10000-flying-hours |title=Portuguese Air Force's AW101 Fleet Achieves 10,000 Flying Hours |publisher=AgustaWestland |date=12 July 2010 |url-status=dead |archive-url=https://web.archive.org/web/20100930093230/http://www.agustawestland.com/news/portuguese-air-forces-aw101-fleet-achieves-10000-flying-hours |archive-date=30 September 2010}}</ref>

===Japan Maritime Self-Defense Force===
[[File:Kawasaki MCH-101 (cropped).jpg|left|thumb|Japanese MCH-101]]

The Japan Maritime Self-Defense Force (JMSDF) ordered 14 aircraft in 2003 to use in both the airborne mine countermeasures (AMCM) and transport roles. The AW101 was modified by [[Company:Kawasaki Heavy Industries|Kawasaki Heavy Industries]], and the Japan Defense Agency designated the model MCH-101. Special features include the automated folding of the rotor and tail.<ref name="khi_news_2006">{{cite web |url= https://global.kawasaki.com/en/corp/newsroom/news/detail/ba_c3060303-1.html |title= First MCH-101 Helicopter Goes to Japan Defense Agency |publisher= KHI |access-date= 13 July 2009 |archive-url= https://web.archive.org/web/20150919164206/http://global.kawasaki.com/en/corp/newsroom/news/detail/ba_c3060303-1.html |archive-date= 19 September 2015 |url-status= live}}</ref> For the mine-hunting role, the MCH-101 has been outfitted with [[Company:Northrop Grumman|Northrop Grumman]]'s AQS-24A airborne mine-hunting system<ref>{{cite web |first= Greg |last= Waldron |url= http://www.flightglobal.com/news/articles/japan-selects-northrop-mine-hunting-gear-for-mch101-fleet-363840/ |title= Japan selects Northrop mine-hunting gear for MCH101 fleet |work= Flight International |date= 25 October 2011 |access-date= 5 January 2012 |archive-url= https://web.archive.org/web/20111110121208/http://www.flightglobal.com/news/articles/japan-selects-northrop-mine-hunting-gear-for-mch101-fleet-363840/ |archive-date= 10 November 2011 |url-status= live}}</ref> and AN/AES-1 Airborne Laser Mine Detection System (ALMDS) for a complete surface-to-bottom mine detection capability, as well as Mk-104 acoustic mine sweeping gear.<ref>[http://navyrecognition.com/index.php/news/naval-exhibitions/2017/mast-asia-2017-show-daily-news/5285-mast-asia-2017-kawasaki-heavy-industries-showcasing-mch-101-mine-warfare-helicopter.html Kawasaki Heavy Industries Showcasing MCH-101 Mine Warfare Helicopter] {{Webarchive|url=https://web.archive.org/web/20170618005944/http://www.navyrecognition.com/index.php/news/naval-exhibitions/2017/mast-asia-2017-show-daily-news/5285-mast-asia-2017-kawasaki-heavy-industries-showcasing-mch-101-mine-warfare-helicopter.html |date=18 June 2017}} – Navyrecognition.com, 14 June 2017</ref>

In 2002, AgustaWestland, Kawasaki and Marubeni entered a general agreement for cooperation; Kawasaki began the assembly of both the CH-101 and the MCH-101 in 2003. Kawasaki also began [[Social:Licensed production|licensed production]] of the RTM322 engines in 2005.<ref>{{cite web |url= http://www.khi.co.jp/english/pressrelease/detail/ba_c3051014-1.html |title= Milestone RTM322 Engine goes to Japan Defense Agency |publisher= KHI |access-date= 21 December 2009 |archive-url= https://web.archive.org/web/20110927001151/http://www.khi.co.jp/english/pressrelease/detail/ba_c3051014-1.html |archive-date= 27 September 2011 |url-status= live}}</ref> In a separate agreement between Marubeni and AgustaWestland, a supply depot was established in Japan to support the MCH-101 and CH-101 fleets.<ref>{{cite web|url=http://www.agustawestland.com/news/marubeni-and-agustawestland-sign-spares-support-agreement |title=Marubeni And AgustaWestland Sign Spares Support Agreement |publisher=AgustaWestland |access-date=1 April 2010 |url-status=dead |archive-url=https://web.archive.org/web/20090625032455/http://www.agustawestland.com/news/marubeni-and-agustawestland-sign-spares-support-agreement |archive-date=25 June 2009}}</ref> The first MCH-101 was delivered to the JMSDF on 3 March 2006.<ref name="khi_news_2006"/>

The MCH-101 will replace the MH-53E (S-80-M-1) in the AMCM role. The CH-101 will operate in the transport/support role for Antarctic expeditions, replacing the Sikorsky S-61A, and will be working in coordination with the Ministry of Education, Culture, Sports, Science and Technology.<ref>{{cite web |url= http://www.khi.co.jp/products/aerospace/airplane_e.html |title= Kawasaki Aircraft |publisher= KHI |access-date=5 February 2010|archive-url= https://web.archive.org/web/20100923070722/http://www.khi.co.jp/products/aerospace/airplane_e.html|archive-date=23 September 2010 |url-status=dead}}</ref>

After a whistle-blower alleged that the MSDF's preference had been improperly changed an investigation was launched. On 16 December 2016 the Japanese Ministry of Defense (the Defense Agency having been upgraded to a ministry in 2007) stated that it had not confirmed lobbying efforts but the ministry admonished Tomohisa Takei, the JMSDF chief of staff, for mentioning the MCH-101 by name during the procurement process to his subordinates. This had come after MSDF officials had reported that the Mitsubishi-built SH helicopters may be best.<ref>[https://www.japantimes.co.jp/news/2016/12/17/national/top-msdf-officer-admonished-meddling-helicopter-procurement-process/ Top MSDF officer admonished for meddling in helicopter procurement process December 17, 2016] {{Webarchive|url=https://web.archive.org/web/20170903205005/https://www.japantimes.co.jp/news/2016/12/17/national/top-msdf-officer-admonished-meddling-helicopter-procurement-process/ |date=3 September 2017}} ''Japan Times''</ref><ref>[http://this.kiji.is/182428324281271805 ヘリ選定で海幕長を訓戒 特定機種例示、公正さ欠く] {{webarchive|url=https://web.archive.org/web/20170904012956/https://this.kiji.is/182428324281271805 |date=4 September 2017}} 共同通信2016年12月16日 {{in lang|ja}}</ref>

===VIP and other usage===
[[File:VH-71 testing near the Lockheed facility in Owego, NY.jpg|thumb|right|AW101 (VH-71) undergoing testing in Owego, New York]]

AgustaWestland developed a specialised luxury variant, the AW101 VVIP (Very Very Important Person, i.e. a head of state), aimed at business and VIP customers.<ref>{{cite web |url= http://www.flightglobal.com/articles/2008/05/19/223796/ebace-2008-agusta-westland-targets-vvips-with-luxury-aw101.html |title= EBACE 2008: Agusta Westland targets VVIPs with luxury AW101 |publisher= Flight Daily News |date= 19 May 2008 |access-date= 6 February 2010 |archive-url= https://web.archive.org/web/20100917234528/http://www.flightglobal.com/articles/2008/05/19/223796/ebace-2008-agusta-westland-targets-vvips-with-luxury-aw101.html |archive-date= 17 September 2010 |url-status= live}}</ref> As of April 2009, 15% of all AW101s sold were for VIP purposes.<ref name='kington'/> By September 2013, customers operating the VIP variant included Saudi Arabia, Algeria, Nigeria and Turkmenistan.<ref name="perry"/>

The AW101 was being acquired by the United States Marine Corps under the VXX program as a replacement for the Presidential Marine One helicopters. Designated ''VH-71 Kestrel'', the variant was heavily customised and equipped with various self-defense systems.<ref name="reg">{{cite web |url= https://www.theregister.co.uk/2009/01/09/air_force_one_replacement/ |title= Could the Airbus A380 be the new Air Force One? – Obama's chopper is European |first= Lewis |last= Page |work= The Register |date= 9 January 2009 |access-date= 10 August 2017 |archive-url= https://web.archive.org/web/20170810135638/https://www.theregister.co.uk/2009/01/09/air_force_one_replacement/ |archive-date= 10 August 2017 |url-status= live}}</ref> However the programme encountered significant cost overruns and political opposition, which led to the procurement being scrapped in June 2009.<ref name="Navy_ends_contract">[http://www.flightglobal.com/articles/2009/06/02/327241/us-navy-terminates-vh-71-presidential-helicopter-contract.html "US Navy Terminates VH-71 Presidential Helicopter Contract".] {{Webarchive|url=https://web.archive.org/web/20090605065032/http://www.flightglobal.com/articles/2009/06/02/327241/us-navy-terminates-vh-71-presidential-helicopter-contract.html|date=5 June 2009}} ''Flight International'', 2 June 2009.</ref>  After the cancellation, the delivered helicopters were sold to Canada for $164 million, where they were used as source of spare parts for its fleet of Agusta Westland CH-149 Cormorant search-and-rescue helicopters. Separately, the Marine Corps had also conducted studies into the adoption of the EH101 as a fallback option to the Bell-Boeing V-22 Osprey [[Engineering:Tiltrotor|tiltrotor]] during the 1990s.<ref name="Janes" />

In April 2009, India ordered 12 AW101 to serve as executive transport helicopters for the Indian President and Prime Minister.<ref>{{cite web |url= http://www.flightglobal.com/articles/2009/08/10/330795/india-approves-deals-for-ka-31-aw101-helicopters.html |title= India approves deals for Ka-31, AW101 helicopters |first= Radhakrishna |last= Rao |work= Flight International |date= 10 August 2009 |archive-url= https://web.archive.org/web/20090813120652/http://www.flightglobal.com/articles/2009/08/10/330795/india-approves-deals-for-ka-31-aw101-helicopters.html |archive-date= 13 August 2009 |url-status= live}}</ref> The selection followed field trial assessments between the AW101 and the Sikorsky S-92 held in 2008.<ref>{{cite news |url= http://timesofindia.indiatimes.com/NEWS/India/PM-President-to-get-swanky-copters/articleshow/4836077.cms |title= PM, President to get swanky copters |work= The Times of India |date= 30 July 2009 |first1= Rajat |last1= Pandit |archive-url= https://web.archive.org/web/20090802200151/http://timesofindia.indiatimes.com/NEWS/India/PM-President-to-get-swanky-copters/articleshow/4836077.cms |archive-date= 2 August 2009 |url-status= live}}</ref> However, the procurement was put on hold and subsequently cancelled due to the [[Engineering:2013 Indian helicopter bribery scandal|2013 Indian helicopter bribery scandal]], in which Finmeccanica, AgustaWestland's parent company, were accused of using bribery to win the contract.<ref>[http://articles.timesofindia.indiatimes.com/2009-07-30/india/28160072_1_agustawestland-helicopters-communication-squadron "PM, President to get swanky copters"] {{Webarchive|url=https://web.archive.org/web/20131004215908/http://articles.timesofindia.indiatimes.com/2009-07-30/india/28160072_1_agustawestland-helicopters-communication-squadron |date=4 October 2013}}. The Times of India, 30 July 2009.</ref><ref>{{cite web |url= https://www.bbc.co.uk/news/world-asia-india-25568464 |title= India scraps $753m Finmeccanica helicopter deal |work= BBC News |date= 1 January 2014 |access-date= 20 June 2018 |archive-url= https://web.archive.org/web/20190204001607/https://www.bbc.co.uk/news/world-asia-india-25568464 |archive-date= 4 February 2019 |url-status= live}}</ref> The three helicopters delivered as part of the contract may be returned to the manufacturer as part of the arbitration process.<ref name="ie4m14">{{cite web|title= India to encash 228 m euros bank guarantees of Agusta|url= http://indianexpress.com/article/india/india-others/india-to-encash-228-m-euros-bank-guarantees-of-agusta/|date= 26 May 2014|work= Indian Express|access-date= 24 July 2014|archive-url= https://web.archive.org/web/20140711100928/http://indianexpress.com/article/india/india-others/india-to-encash-228-m-euros-bank-guarantees-of-agusta/|archive-date= 11 July 2014|url-status= live}}</ref>

==Variants==
;Pre-production
* ''PP1'' – Westland-built basic air vehicle prototype, first flown 9 October 1987.<ref name="iapr22 p122">Lake 2007, p. 122.</ref>
* ''PP2'' – Agusta-built Italian basic air vehicle prototype first flown on 26 November 1987 and used for deck trials but was destroyed on 21 January 1993 following a rotor brake malfunction.<ref name="iapr22 p122"/><ref name="flightrotor">{{cite magazine|title=EH101 crash caused by rotor brake|magazine=Flight International|issue=19–25 May 1995|page=5|url=http://www.flightglobal.com/pdfarchive/view/1993/1993%20-%201144.html|access-date=3 January 2012|archive-url=https://web.archive.org/web/20120308214147/http://www.flightglobal.com/pdfarchive/view/1993/1993%20-%201144.html|archive-date=8 March 2012|url-status=live}}</ref>
* ''PP3'' – Westland-built and the first civil configured ''Heliliner'', used for engine vibration tests and icing trials in Canada.<ref name="iapr22 p122"/>
* ''PP4'' – Westland-built British naval prototype, lost in an accident on 7 April 1995 after a drive train control rod failure.<ref name="iapr22 p122-3">Lake 2007, pp. 122–123.</ref>
* ''PP5'' – Westland-built Merlin development aircraft eventually equipped with Merlin avionics.<ref name="iapr22 p123">Lake 2007, p. 123.</ref>
* ''PP6'' – Agusta-built development aircraft for Italian Navy variant first flown 26 April 1989.<ref name="iapr22 p123"/>
* ''PP7'' – Agusta-built military utility aircraft with rear-loading ramp.<ref name="iapr22 p123"/>
* ''PP8'' – Westland-built civil prototype.<ref name="iapr22 p123"/>
* ''PP9'' – Agusta-built military utility prototype with rear-loading ramp.<ref name="iapr22 p123"/>
;Model 110
: Italian Navy ASW/ASuW variant, eight built. Powered by T-700-GE-T6A1 engines. Fitted with Eliradar APS-784 radar and Honeywell [[Engineering:HELRAS|HELRAS]] dipping sonar. Armed with torpedoes or Marte anti-ship missiles.<ref name="iapr22 p123"/>
[[File:MerlinFlares.jpg|thumb|upright|Composite image of an RAF Merlin deploying flares]]
;Model 111
: Royal Navy ASW/ASuW variant, designated Merlin HM1 by customer. Powered by RTM322 engines and fitted with Blue Kestrel radar, Thomson Marconi FLASH dipping sonar and Orange Reaper ESM. 44 built.<ref name="iapr22 p124">Lake 2007, p. 124.</ref>
;Model 112
: Italian Navy early warning variant with same airframe as Model 110 but with Eliradar HEW-784 radar in large underfuselage radome. Four built.<ref name="iapr22 p125">Lake 2007, p. 125.</ref>
;Series 200
: Proposed military utility version with no rear-loading ramp.<ref name="iapr22 p125"/>
;Series 300 Heliliner
: Proposed civil transport with no ramp.<ref name="iapr22 p125-6">Lake 2007, pp. 125–126.</ref> In 2000, British International Helicopters conducted service trials using ''PP8''; these did not lead to a commercial service.<ref name="RAF museum"/>
;Series 310
: Proposed version of Heliliner with full airline avionics for operation from oil platforms. No production.<ref name="iapr22 p126">Lake 2007, p. 126.</ref>
;Model 410
: Italian Navy transport variant with folding rotors and tail boom. Four built.<ref name="iapr22 p126"/>
;Model 411
: Royal Air Force transport variant, designated Merlin HC3 by customer, 22 built.<ref name="iapr22 p126-7">Lake 2007, pp. 126–127.</ref>
;Model 413
: Italian Navy special forces and amphibious assault transport with more advanced avionics.<ref name="iapr22 p128">Lake 2007, p. 128.</ref>
;Model 500
: Proposed civil utility variant with rear-ramp.<ref name="iapr22 p128"/>
;Model 510
: Civil utility variant with rear ramp, two built. One used for Tokyo Metropolitan Police Agency and one used to support US101 bid.<ref name="iapr22 p128"/>
;Model 511
: Canadian military search and rescue variant, designated CH-149 Cormorant by customer.<ref name="iapr22 p128-9">Lake 2007, pp. 128–129.</ref>
;Model 512
: Merlin Joint Supporter for Royal Danish Air Force. Eight acquired for search and rescue (''512 SAR'') and six for tactical troop transport (''512 TTT''). The six transports were sold to RAF (as Merlin HC3As) and replaced by six new-build Merlins.<ref name="iapr22 p129=1">Lake 2007, pp. 129–131.</ref>
;Model 514
: Portuguese Air Force search and rescue variant, six built.<ref name="key aero">{{cite web|first=Gary |last=Parsons |url=http://www.key.aero/view_news.asp?ID=2241&thisSection=military |title=Portugal's AW101 passes 10,000&nbsp;hours |publisher=Key Aero |date=13 July 2010 |url-status=dead |archive-url=https://web.archive.org/web/20140408225305/http://www.key.aero/view_news.asp?ID=2241&thisSection=military |archive-date=8 April 2014}}</ref>
;Model 515
: Portuguese Air Force fisheries protection variant, two built.<ref name="key aero"/>
;Model 516
: Portuguese Air Force combat search and rescue variant, four built.<ref name="key aero"/>
;Model 518
: Japanese Maritime Self-Defense Force mine countermeasures and transport variant, two built.
;Model 519
:Presidential Transport variant for the United States Marine Corps as the VH-71 Kestrel, four test vehicles and five pilot production aircraft built.<ref name=reg/>
;Model 610
: Algerian Naval variant. 6 delivered.<ref name="ConstructionList">{{cite web |url= https://www.planelogger.com/Aircraft/ConstructionList/AW101 |title= Construction List – AW101 |publisher= Planelogger |access-date= 13 July 2009 |archive-url= https://web.archive.org/web/20190410001935/https://www.planelogger.com/Aircraft/ConstructionList/AW101 |archive-date= 10 April 2019 |url-status= live}}</ref>
;Model 611
: Italian Air Force Combat Search and Rescue variant, powered by CT7-8E engines.<ref>{{cite web|title=AW101 611|url=http://www.helis.com/database/model/1306/|website=www.helis.com|access-date=18 January 2015|archive-url=https://web.archive.org/web/20150118192514/http://www.helis.com/database/model/1306/|archive-date=18 January 2015|url-status=live}}</ref> 15 on order.
;Model 612
: Norwegian search and rescue variant, operated by the Air Force. 16 ordered with option for 6 more.<ref name="Norway min">{{cite web |url= http://www.regjeringen.no/en/dep/jd/press-center/pressemeldinger/20131/agustawestland-to-final-negotiations.html?id=745358 |title= AgustaWestland to final negotiations |date= 8 November 2013 |publisher= Royal Norwegian Ministry of Justice and the Police |access-date= 8 November 2013 |archive-url= https://web.archive.org/web/20131110154255/http://www.regjeringen.no/en/dep/jd/press-center/pressemeldinger/20131/agustawestland-to-final-negotiations.html?id=745358 |archive-date= 10 November 2013 |url-status= live}}</ref> 
;Model 640
: Saudi Arabian VVIP variant, operated by the Air Force. 2 delivered.<ref name="ConstructionList"/>
;Model 641
: Indian VVIP variant. (See [[Engineering:2013 Indian helicopter bribery scandal|2013 Indian helicopter bribery scandal]]). Latterly delivered to Nigerian and Azerbaijani Air Forces.<ref name="ConstructionList"/>
;Model 642
: Algerian VVIP variant, 2 delivered.<ref name="ConstructionList"/>
;Model 643
: Turkmenistani VVIP variant, operated by the Air Force. 2 delivered. .<ref name="ConstructionList"/>
;Merlin HM1
: Royal Navy designation for the Model 111.<ref name="rn-nas"/>
;Merlin HM2
: Avionics retrofit of 30 HM1s for the Royal Navy.<ref name="janes 14"/>
[[File:Merlin Helicopter Carrying 105mm Light Gun MOD 45155696.jpg|thumb|RAF Merlin carrying a [[Engineering:L118 light gun|L118]] 105&nbsp;mm howitzer.]]
;Merlin HC3
: Royal Air Force designation for the Model 411.<ref name="RAF HC3"/>
;Merlin HC3A
: Royal Air Force designation for six former Royal Danish Air Force Model 512s modified to UK standards.<ref name='danish special'/>
;Merlin HC3i
: Royal Navy will fit seven HC3 with folding rotor heads as an interim (3i) measure until the full HC4 upgrade is available.<ref name="AW20140127" />
;Merlin HC4/4A
: The conversion of 25 RAF HC3/3A for RN use in hand with the first flight taking place in November 2016.<ref>{{cite web|last1=Jennings|first1=Gareth|title=Upgraded Merlin HC4/4A for Royal Marines makes maiden flight|url=http://www.janes.com/article/65083/upgraded-merlin-hc4-4a-for-royal-marines-makes-maiden-flight|website=IHS Jane's 360|access-date=7 November 2016|archive-url=https://web.archive.org/web/20161107155820/http://www.janes.com/article/65083/upgraded-merlin-hc4-4a-for-royal-marines-makes-maiden-flight|archive-date=7 November 2016|url-status=live}}</ref> HM2 cockpit, folding tail/blades and other adaptations for naval use.<ref name="AW20140127" />
;CH-148 Petrel
: Ship-based anti-submarine helicopter for Canada. 35 originally ordered by the Canadian Forces, reduced to 28 and cancelled in 1993.<ref name="iapr22 p125"/>
;CH-149 Chimo
: Search and rescue helicopter for Canada. 15 ordered by the Canadian forces, but later cancelled.<ref name="iapr22 p125"/>
;CH-149 Cormorant
:Search and rescue helicopter for Canada, 15 ordered and delivered.<ref name='plam 152'/>
;Lockheed Martin VH-71 Kestrel
:Cancelled USMC variant that was intended to serve as the US Presidential helicopter.<ref name=reg/>
;SH-101A
:Italian Navy designation for the MP variant.<ref name="dgaa">{{cite web |url= http://www.dgaa.it/newsletter/newsletter60/AER-0-0-12.pdf |title= Utilizzo Della Nomenclatura 'Mission Design Series' (MDS) Neele Pubblicazioni Tecniche (PPTT) Di Competenza Della Daa |publisher= Ministero Della Defesa |date= June 2011 |access-date= 15 July 2012 |archive-url= https://web.archive.org/web/20131220014637/http://www.dgaa.it/newsletter/newsletter60/AER-0-0-12.pdf |archive-date= 20 December 2013 |url-status= live}}</ref>
[[File:HH-101A Caesar 7731.jpg|right|thumb|Italian Air Force HH-101A]]
;EH-101A
:Italian Navy designation for the AEW variant.<ref name="dgaa" />
;MH-101A
:Italian Navy designation for the Amphibious Support Helicopter (ASH) variant.<ref name="dgaa" />
;HH-101A
:Italian Air Force designation for the CSAR variant.<ref>{{cite web|url=http://www.flightglobal.com/news/articles/pictures-first-italian-air-force-hh-101a-breaks-cover-397221/|title=PICTURES: First Italian air force HH-101A breaks cover|author=Reed Business Information Limited|work=flightglobal.com|access-date=23 July 2015|archive-url=https://web.archive.org/web/20150723181320/http://www.flightglobal.com/news/articles/pictures-first-italian-air-force-hh-101a-breaks-cover-397221/|archive-date=23 July 2015|url-status=live}}</ref>
;[[Company:Kawasaki Heavy Industries|Kawasaki Heavy Industries]] MCH-101<ref name="khi_news_2006"/>
:Japan Defense Agency designation of Model 518

==Operators==
<!--READ FIRST: This section is for cited entries only. Please do not add entries into this list without a citation from a reliable source. All entries without a citation will be removed. Thank you.-->

===Government===
[[File:AgustaWestland AW101 operators.svg|thumb|400px|right|Map of current AW101 operators]]
[[File:Agusta-Westland EH-101 Merlin, Portugal - Air Force JP7566533.jpg|thumb|right|A Portuguese Merlin lifts off from Monte Real Air Base]]
;{{DZA}}
* {{wipe|Algerian Air Force}}<ref>{{cite news |last= Allport |first= Dave |title= First Algerian VIP AW 101 Flight Testing |work= {{wipe|Air Forces Monthly}} |date= July 2013}}</ref>
* Algerian Navy<ref name="World Air Forces 2018">{{cite web|url =https://www.flightglobal.com/asset/21905/waf/|title =World Air Forces 2018|publisher =Flightglobal Insight|year =2018|access-date =25 August 2018|archive-url =https://web.archive.org/web/20180206123925/https://www.flightglobal.com/asset/21905/waf/|archive-date =6 February 2018|url-status =live}}</ref>
;{{CAN}}
* {{wipe|Royal Canadian Air Force}} (see [[Engineering:AgustaWestland CH-149 Cormorant#Operators|CH-149 Cormorant]])
;{{DNK}}
* {{wipe|Royal Danish Air Force}}<ref name="World Air Forces 2018"/>
;{{IDN}}
*{{wipe|Indonesian Air Force}}<ref name="World Air Forces 2018"/>
;{{ITA}}
* {{wipe|Italian Air Force}}<ref name="World Air Forces 2018"/><ref>{{cite web | url = http://www.aeronautica.difesa.it/mezzi/mlinea/Pagine/HH101A.aspx | title = HH-101A | publisher = Aeronautica Militare | access-date = 4 June 2019}}</ref>
[[File:Agusta-Westland EH-101-410 Merlin, Italy - Navy JP7306257.jpg|thumb|right|An Italian Navy AW101 flies over the carrier {{ship|Italian aircraft carrier|Cavour||2}}]]
* Italian Navy<ref name="World Air Forces 2018"/><ref>{{cite web | url = http://www.marina.difesa.it/noi-siamo-la-marina/mezzi/forze-aeree/Pagine/AgustaWestlandEH101ASH.aspx | title = MH-101A | publisher = Marina Militare | access-date = 4 June 2019}}</ref>
;{{JPN}}
* Japan Maritime Self-Defense Force<ref name="World Air Forces 2018"/>
* Tokyo Metropolitan Police Department<ref>{{cite web|url=http://www.helis.com/database/modelorg/344/|title=Tokyo Metropolitan Police Department EH -101|access-date=17 February 2013|archive-url=https://web.archive.org/web/20130619094231/http://www.helis.com/database/modelorg/344/|archive-date=19 June 2013|url-status=live}}</ref>
;{{NGR}}
* {{wipe|Nigerian Air Force}}<ref>{{cite web|url=http://www.flightglobal.com/news/articles/nigerian-aw101-makes-debut-flight-404100/|title=Nigerian AW101 makes debut flight|author=Reed Business Information Limited|work=flightglobal.com|access-date=23 July 2015|archive-url=https://web.archive.org/web/20150723182130/http://www.flightglobal.com/news/articles/nigerian-aw101-makes-debut-flight-404100/|archive-date=23 July 2015|url-status=live}}</ref><ref>{{cite web|url=http://www.defenceweb.co.za/index.php?option=com_content&view=article&id=37030:first-nigerian-vip-aw101-delivered&catid=124:military-helicopters&Itemid=282|title=First Nigerian VIP AW101 delivered|author=Guy Martin|work=defenceweb.co.za|access-date=23 July 2015|archive-url=https://web.archive.org/web/20150723185153/http://www.defenceweb.co.za/index.php?option=com_content&view=article&id=37030:first-nigerian-vip-aw101-delivered&catid=124:military-helicopters&Itemid=282|archive-date=23 July 2015|url-status=live}}</ref>
;{{NOR}}
* {{wipe|Royal Norwegian Air Force}}<ref name="World Air Forces 2018"/>
;{{POL}}
*Polish Navy (4 on order)<ref>{{cite web |last=Perry |first=Donald |title=Poland orders four AW101 helicopters for navy |website=Flightglobal |date=26 April 2019 |url=https://www.flightglobal.com/news/articles/poland-orders-four-aw101-helicopters-for-navy-457715/ |access-date=26 April 2019 |archive-url=https://web.archive.org/web/20190426112458/https://www.flightglobal.com/news/articles/poland-orders-four-aw101-helicopters-for-navy-457715/ |archive-date=26 April 2019 |url-status=live}}</ref>
;{{PRT}}
* {{wipe|Portuguese Air Force}}<ref name="World Air Forces 2018"/>
;{{SAU}}
[[File:Eh101 keishicho.jpg|thumb|Tokyo Metropolitan Police Department AW101]]
* {{wipe|Royal Saudi Air Force}}<ref>{{cite web |url= https://theaviationist.com/2014/01/22/aw-101-to-carry-hollande/ |title= French President flies on (made in Italy) VVIP chopper in Saudi Arabia |publisher= theaviationist.com |date= 22 January 2014 |access-date= 25 August 2018 |archive-url= https://web.archive.org/web/20180828102435/https://theaviationist.com/2014/01/22/aw-101-to-carry-hollande/ |archive-date= 28 August 2018 |url-status= live}}</ref>
;{{TKM}}
* {{wipe|Turkmen Air Force}}<ref name="World Air Forces 2018"/>
;{{GBR}}
* Royal Navy<ref name="World Air Forces 2018"/>

===Former operators===
;{{GBR}}
* {{wipe|Royal Air Force}}<ref name="World Air Forces 2015">{{cite web|url=http://forms.flightglobal.com/WorldAirForces2015?product=PREM&mode=DOWNLOAD&DMDcode=FGWC4&fcid=%7B05ceef25-b72e-4bea-9a83-a7ab7d02e55a%7D_FC078_PREM_201412&fcfileext=pdf|title=World Air Forces 2015|publisher=Flightglobal Insight|year=2015|access-date=4 January 2015|archive-url=https://web.archive.org/web/20150324102339/http://forms.flightglobal.com/WorldAirForces2015?product=PREM&mode=DOWNLOAD&DMDcode=FGWC4&fcid=%7B05ceef25-b72e-4bea-9a83-a7ab7d02e55a%7D_FC078_PREM_201412&fcfileext=pdf|archive-date=24 March 2015|url-status=live}}</ref>

==Notable accidents==

==Specifications (Merlin HM1)==
[[File:AW EH101.png|400px|right|Views of the AW101]]
[[File:Aa merlin southport 2010 bladeend.jpg|thumb|The shovel-shaped BERP rotor blade tips of an RAF Merlin HC3]]

{{Aircraft specs
|ref=Jane's All The World's Aircraft 2003–2004,<ref name="jawa03 p233-8">Jackson 2003, pp. 233–238.</ref> AgustaWestland<ref name="awRef">[http://www.agustawestland.com/product/aw101-1 "AW101."] {{webarchive|url=https://web.archive.org/web/20120106081142/http://www.agustawestland.com/product/aw101-1 |date=6 January 2012}} ''AgustaWestland'', Retrieved: 4 July 2014.</ref>
|prime units?=met
<!--
        General characteristics
-->
|crew=3–4
|capacity=<br />
:* 26 troops (38 passengers) or 5 tonnes of payload or 4 stretchers (with sonar array removed) for Merlin HM1;<ref name="iapr22 p125"/>
:* 30 seated troops or 45 standing fully equipped combat troops, or 3,050&nbsp;kg (6,724 lb) of internal payload, 5,520&nbsp;kg (12,169 lb) of external payload, or 16 stretchers for AW101<ref name="awRef"/>
|length m=19.53
|length note=fuselage
|height m=6.62
|airfoil=
|empty weight kg=10500
|empty weight note=
|gross weight kg=
|gross weight note=
|max takeoff weight kg=14600
|max takeoff weight note=
|fuel capacity=
|more general=
<!--
        Powerplant
-->
|eng1 number=3
|eng1 name=[[Engineering:Rolls-Royce Turbomeca RTM322|Rolls-Royce Turbomeca RTM322-01]]
|eng1 type=[[Engineering:Turboshaft|turboshaft]] engines
|eng1 kw=1566
|eng1 note=(take-off power)

|rot number=1
|rot dia m=18.59
|rot area sqm=271.51
|rot area note='''root:''' RAE 9651 ; '''tip:''' RAE 9645/RAE 9634<ref name="Selig">{{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=16 April 2019}}</ref>
<!--
        Performance
-->
|max speed kmh=
|max speed note=
|cruise speed kmh=278
|cruise speed note=
|never exceed speed kmh=309
|never exceed speed note=
|range km=833
|range note=<ref name="rnmerlin2">{{cite web|title=Merlin Mk1 |url=http://www.royalnavy.mod.uk/The-Fleet/Aircraft/Helicopters/Merlin-MK1 |publisher=Royal Navy |access-date=4 January 2012 |url-status=dead |archive-url=https://web.archive.org/web/20111231205619/http://www.royalnavy.mod.uk/The-Fleet/Aircraft/Helicopters/Merlin-MK1 |archive-date=31 December 2011}}</ref>
|combat range km=
|combat range note=
|ferry range km=
|ferry range note=
|endurance=5 hours
|ceiling m=4575
|ceiling note=
|climb rate ms=
|climb rate note=
|time to altitude=
|disk loading kg/m2=
|disk loading note=
|fuel consumption kg/km=
|power/mass=
|more performance=
<!--
        Armament
-->
|bombs= 4× Sting Ray homing [[Engineering:Torpedo|torpedo]]es or Mk 11 depth charges<ref>{{cite book|last=Kulshrestha|first=Sanatan|title=Naval Strategic Insight|url=https://books.google.com/books?id=TpxIDwAAQBAJ&pg=PA11|year=2015|publisher=IndraStra Global|page=11}}</ref>
|avionics=
* Smiths Industries OMI 20 SEP<!--Note to AWB users -this is not a date- don't correct it--> dual-redundant digital automatic flight control system
* Navigation systems:
** BAE Systems LINS 300 ring laser gyro, [[Company:Litton Industries|Litton]] Italia LISA-4000 [[Earth:Inertial navigation system#Strapdown systems|strapdown]] [[Engineering:Attitude and heading reference system|attitude and heading reference system]]
* [[Engineering:Radar|Radar]]:
** Selex Galileo Blue Kestrel 5000 maritime surveillance radar
* [[Social:Electronic countermeasure|ECM]]
** Racal Orange Reaper ESM
* Sonar
** Thomson Marconi Sonar AQS-903 acoustic processor
** Active/passive sonobuoys
** Thomson Sintra FLASH dipping sonar array
}}

==Notable appearances in media==
<!-- All content about the aircraft in fictional and gaming use has been moved to Aircraft in fiction, please see [[WP:AIRPOP -->

==See also==
{{aircontent
|see also=
* Agusta A.101
|related=
* [[Engineering:AgustaWestland CH-149 Cormorant|AgustaWestland CH-149 Cormorant]]
* Lockheed Martin VH-71 Kestrel
|similar aircraft=
* [[Engineering:Changhe Z-18|Changhe Z-18]]
* [[Engineering:Eurocopter EC725|Eurocopter EC725]]
* [[Engineering:Mil Mi-17|Mil Mi-17]]
* Mil Mi-38
* [[Engineering:Sikorsky CH-148 Cyclone|Sikorsky CH-148 Cyclone]]
* Sikorsky S-92
|lists=
* [[Engineering:List of rotorcraft|List of rotorcraft]]
* [[Engineering:List of active United Kingdom military aircraft|List of active United Kingdom military aircraft]]
}}

==References==
;Citations
{{Reflist|30em}}

;Bibliography
{{Refbegin}}
* AgustaWestland. [http://www.agustawestland.com/sites/default/files/brochures_new_product/AW101%20Utility.pdf ''AW101 Utility''.]{{dead link|date=October 2016 |bot=InternetArchiveBot |fix-attempted=yes}} AgustaWestland, June 2008.
* Cooper, Neil. ''The business of death: Britain's arms trade at home and abroad''. I.B.Tauris, 1997. {{ISBN|1-85043-953-2}}.
* Crawford, Stephen. ''Twenty-first century military helicopters: today's fighting gunships''. Zenith Imprint, 2003. {{ISBN|0-7603-1504-3}}.
* Dobbin, Murray. ''The politics of Kim Campbell: from school trustee to Prime Minister''. James Lorimer & Company, 1993. {{ISBN|1-55028-413-4}}.
* Donald, David, ed. ''The Complete Encyclopedia of World Aircraft''. New York: Barnes & Noble Books, 1997. {{ISBN|0-7607-0592-5}}.
* Eden, Paul, ed. ''Encyclopedia of Modern Military Aircraft''. London: Amber Books, 2004. {{ISBN|1-904687-84-9}}.
* Evans, Nicholas D. ''Military gadgets: how advanced technology is transforming today's battlefield-- and tomorrow's''. FT Press, 2004. {{ISBN|0-13-144021-7}}.
* Frawley, Gerald. ''The International Directory of Military Aircraft, 2002/2003''. Fyshwick, ACT, Australia: Aerospace Publications, 2002. {{ISBN|1-875671-55-2}}.
* Friedman, Norman. ''The Naval Institute guide to world naval weapons systems, 1997–1998''. Annapolis, Maryland, USA: Naval Institute Press, 1997. {{ISBN|1-55750-268-4}}.
* Gunston, Bill and Mike Spick. ''Modern fighting helicopters''. Random House Value Publishing, 1986. {{ISBN|0-517-61349-2}}.
* Harding, Ian. "Long distance wizard". ''Air International'', Vol. 79, No. 1, July 2010. pp.&nbsp;70–75. {{ISSN|0306-5634}}.
* Jackson, Paul. ''Jane's All The World's Aircraft 2003–2004''. 2003, Jane's Information Group. Coulsdon, UK. {{ISBN|0-7106-2537-5}}
* Jackson, Paul; Munson, Kenneth; Peacock, Lindsay. ''Jane's All The World's Aircraft 2009–2010''. 2009, Jane's Information Group. Coulsdon, UK. {{ISBN|0-7106-2880-3}}
* Lake, Jon. "Variant File: AgustaWestland EH101/AW101". ''International Air Power Review''. Volume 22. Westport, Connecticut, USA: AIRtime Publishing, 2007. pp.&nbsp;116–135. {{ISBN|1-88058-879-X}}. {{ISSN|1473-9917}}.
* Lavington, Simon. ''Moving Targets: Elliott-Automation and the Dawn of the Computer Age in Britain, 1947–67''. Springer 2011, {{ISBN|1-84882-932-9}}.
* Martin, Stephen. ''The economics of offsets: defence procurement and countertrade''. Routledge, 1996. {{ISBN|3-7186-5782-1}}.
* Matthews, Ron. ''European armaments collaboration: policy, problems and prospects''. Routledge, 1992. {{ISBN|3-7186-5244-7}}.
* Moir, Ian and Allan G. Seabridge. ''Aircraft systems: mechanical, electrical, and avionics subsystems integration''. John Wiley and Sons, 2008. {{ISBN|0-470-05996-6}}.
* Plamondon, Aaron. ''The politics of procurement: military acquisition in Canada and the Sea King helicopter''. UBC Press, 2009. {{ISBN|0-7748-1714-3}}.
{{Refend}}

== External links ==
{{Commons and category}}
* [https://www.royalnavy.mod.uk/the-equipment/aircraft/helicopters/merlin-mk2 Royal Navy Merlin Mk2 web page]
* [https://www.royalnavy.mod.uk/the-equipment/aircraft/helicopters/merlin-mk4 Royal Navy Merlin Mk4 web page]
* [https://web.archive.org/web/20090620003601/http://www.emfa.pt/www/aeronavesdetalhe.php?lang=ing&cod=eh101 EH-101 Merlin page (in English) on Portuguese Air Force site]
* [https://web.archive.org/web/20080612172508/http://www.danskpanser.dk/Helikoptere/Merlin.htm Danish EH-101 Merlin page]


[[Category:Military helicopters]]

{{Sourceattribution|AgustaWestland AW101|1}}