Editing Boeing AH-64 Apache (section)

==Development==
===Advanced Attack Helicopter===
{{main|Advanced Attack Helicopter}}
[[File:Hughes experimental copter.jpg|thumb|right|An early [[Hughes Helicopters|Hughes]] YAH-64 prototype with T-tail]]

After the [[Lockheed AH-56 Cheyenne|AH-56 Cheyenne]] was cancelled in 1972 in favor of projects like the [[U.S. Air Force]] [[Fairchild Republic A-10 Thunderbolt II|A-10 Thunderbolt II]] and the [[United States Marine Corps|Marine Corps]] [[Hawker Siddeley Harrier|AV-8A Harrier]], the United States Army sought an aircraft to fill an anti-armor attack role that would still be under Army command.<ref>{{cite news |title=Army Cancels Helicopter Contract |newspaper= Victoria Advocate |date= 10 August 1972}}</ref><ref>{{cite news |url=https://news.google.co.uk/newspapers?id=j8kPAAAAIBAJ&sjid=No0DAAAAIBAJ&pg=5294,127450&dq=advanced+attack+helicopter&hl=en |title=Army Decides To Scrap Cheyenne Helicopter Gunship |newspaper=Boca Raton News |date=3 September 1972}}</ref> The 1948 [[Key West Agreement]] forbade the Army from owning combat fixed-wing aircraft. The Army wanted an aircraft better than the [[Bell AH-1 Cobra|AH-1 Cobra]] in firepower, performance, and range. It would have the maneuverability for terrain following [[nap-of-the-earth]] (NoE) flying.<ref name=Bishop_p5>Bishop 2005, pp. 5–6.</ref> To this end, the U.S. Army issued a Request For Proposals (RFP) for the Advanced Attack Helicopter (AAH) program on 15 November 1972.<ref name=Army_p10>OAVCSA 1973, p. 10.</ref><ref>{{cite news |url=https://www.nytimes.com/1972/11/16/archives/army-seeking-bids-on-new-helicopter.html |title=Army Seeking Bids on New Helicopter |work=[[The New York Times]] |date=16 November 1972}}</ref> As a sign of the importance of this project, in September 1973 the Army designated its five most important projects as the "Big Five", with the AAH included.<ref>{{cite web |url=https://news.google.co.uk/newspapers?id=H64hAAAAIBAJ&sjid=hpoFAAAAIBAJ&pg=1762,200656&dq=advanced+attack+helicopter&hl=en |title=New Army Tactic |website=Reading Eagle |date=11 September 1973}}</ref>

Proposals were submitted by [[Bell Helicopter|Bell]], [[Boeing Rotorcraft Systems|Boeing Vertol]]/[[Grumman]] team, [[Hughes Aircraft|Hughes]], [[Lockheed Corporation|Lockheed]], and [[Sikorsky Aircraft|Sikorsky]]. In July 1973, the U.S. Department of Defense selected finalists Bell and Hughes Aircraft's Toolco Aircraft Division (later [[Hughes Helicopters]]). This began the phase 1 of the competition.<ref name=Bishop_p7>Bishop 2005, p. 7.</ref> Each company built prototype helicopters and went through a flight test program. Hughes' ''Model 77/YAH-64A'' prototype first flew on 30 September 1975, while Bell's [[Bell YAH-63|Model 409/YAH-63A]] prototype first flew on 1 October 1975. After evaluating the test results, the Army selected Hughes' YAH-64A over Bell's YAH-63A in 1976. Reasons for selecting the YAH-64A included its more damage tolerant four-blade main rotor and the instability of the YAH-63's [[tricycle landing gear]] arrangement.<ref name=Richardson_Peacock_p8>Richardson and Peacock 1992, p. 8.</ref><ref name=Donald_p114>Donald 2004, p. 114.</ref>

The AH-64A then entered phase 2 of the AAH program under which three pre-production AH-64s would be built, additionally, the two YAH-64A flight prototypes and the ground test unit were upgraded to the same standard.<ref name=Richardson_Peacock_p8/> Weapons and sensor systems were integrated and tested during this time, including the laser-guided [[AGM-114 Hellfire]] missile.<ref name=Bishop_p8>Bishop 2005, p. 8.</ref> Development of the Hellfire missile had begun in 1974, originally known by the name of ''Helicopter Launched, Fire and Forget Missile'' ('Hellfire' being a shortened acronym),<ref>{{cite web |url=http://www.boeing.com/history/bna/hellfire.htm |title=AGM-114 Hellfire missile |publisher=Boeing |access-date=30 July 2011 |url-status=dead |archive-url=https://web.archive.org/web/20110914210609/http://www.boeing.com/history/bna/hellfire.htm |archive-date=14 September 2011}}</ref> for the purpose of arming helicopter platforms with an effective anti-tank missile.{{citation needed|date=February 2023}}

===Into production===
[[File:YAH-64, 1982-03-18.jpg|thumb|left|A YAH-64A prototype, 1982]]

In 1981, three pre-production AH-64As were handed over to the U.S. Army for Operational Test II. The Army testing was successful, but afterward it was decided to upgrade to the more powerful [[General Electric T700|T700-GE-701]] version of engine, rated at {{convert|1690|shp|abbr=on|lk=on}}. The AH-64 was named the ''Apache'' in late 1981, after the [[Apache]] tribe, following the tradition of naming Army helicopters after Native American tribes. It was approved for full-scale production in 1982.<ref name="Bishop_p8-9">Bishop 2005, pp. 8–9.</ref> In 1983, the first production helicopter was rolled out at Hughes Helicopter's facility at [[Mesa, Arizona]]. Hughes Helicopters was purchased by [[McDonnell Douglas]] for $470 million in 1984 ({{Inflation|US|470000000|1984|fmt=eq|r=-6}}).<ref name=Donald_p119>Donald 2004, p. 119.</ref> The helicopter unit later became part of The Boeing Company with the merger of [[Boeing]] and McDonnell Douglas in August 1997.<ref name=Boe_MDC_merge>{{cite web |url=http://www.stltoday.com/stltoday/news/special/pd125.nsf/0/0EC17704770E83BF86256E04006C5943?OpenDocument |title=McDonnell-Boeing Merger |website=St. Louis Post-Dispatch |first=Cynthia |last=Wilson |author2=Dale Singer |date=13 January 2004}}{{dead link|date=August 2017|bot=medic}}{{cbignore|bot=medic}}</ref> In 1986, the incremental or flyaway cost for the AH-64A was $7M and the average unit cost was approximately $13.9M based on total costs.<ref name=Donald_p119/>

A 1985 Department of Defense engineering analysis by the inspector general's office reported that significant design deficiencies still needed to be addressed by the contractor. The Army project manager Col. [[William H. Forster]] published a list of 101 action items. In 1986, the four 22-foot-long main rotor blades, each made from steel and composite material glued together to maximize strength and minimize weight by the Composite Structures Division of Alcoa Composites, were added to the list. The steel-composite rotors could not meet the Army specification for a life of 1500 flight hours, and needed replacement after just 146 hours. After six changes to the design, the rotor blade life was extended to 1400 hours by early 1991.<ref>{{cite news |url=https://www.washingtonpost.com/archive/politics/1991/02/20/temperamental-helicopter-joins-battle/7070af42-9f1a-4e45-95e0-b0d0d20c3d50/ |title=Temperamental Helicopter Joins Battle |first=Charles R. |last=Babcock |date=20 February 1991 |newspaper=The Washington Post |access-date=14 October 2021}}</ref>

As of 2024, the AH-64E is being produced at an economical rate of 82 aircraft a year. Boeing states that the minimum sustainment rate for the aircraft is 48 per year while current tooling and space allows for up to 98 aircraft to be manufactured per year. The U.S. Army states that with additional investment and labor, production could be raised to 144 aircraft per year.<ref name="Volume 1" />

===Further development===
During the 1980s, McDonnell Douglas studied an AH-64B, featuring an updated cockpit, new [[fire control system]] and other upgrades. In 1988, funding was approved for a multi-stage upgrade program to improve sensor and weapon systems.<ref>{{cite news |title=Helicopter Contract Awarded |publisher=Prescott Courier |date=17 August 1988}}</ref> Technological advance led to the program's cancellation in favor of more ambitious changes. In August 1990, development of the AH-64D Apache Longbow was approved by the [[Defense Acquisition Board]]. The first AH-64D prototype flew on 15 April 1992.<ref name="Donald_p150-3">Donald 2004, pp. 150–153.</ref> Prototype testing ended in April 1995. During testing, six AH-64D helicopters were pitted against a bigger group of AH-64As. The results demonstrated the AH-64D to have a sevenfold increase in survivability and fourfold increase in lethality compared to the AH-64A.<ref>[http://military.discovery.com/tv-shows/great-planes/videos/great-planes-the-deadly-apache.htm "Great Planes: Apache Helicopter"] {{webarchive |url=https://web.archive.org/web/20130117140912/http://military.discovery.com/tv-shows/great-planes/videos/great-planes-the-deadly-apache.htm |date=17 January 2013}}. Military Channel</ref><ref>{{cite news |url=http://www.accessmylibrary.com/article-1G1-16790134/dod-halts-apache-longbow.html |archive-url=https://archive.today/20120720084317/http://www.accessmylibrary.com/article-1G1-16790134/dod-halts-apache-longbow.html |url-status=dead |archive-date=20 July 2012 |title=DOD Halts Apache Longbow Tests Early |work=Defense Daily |last=Foote |first=Sheila |date=4 April 1995}}</ref><ref name="Donald_p156-8">Donald 2004, pp. 156–158.</ref> On 13 October 1995, full-scale production was approved;<ref>{{cite news |url=http://www.accessmylibrary.com/article-1G1-17609179/dod-approves-production-longbow.html |archive-url=https://archive.today/20120718091721/http://www.accessmylibrary.com/article-1G1-17609179/dod-approves-production-longbow.html |url-status=dead |archive-date=18 July 2012 |title=DoD Approves Production of Longbow Apache Attack Helicopter |work=Defense Daily |last=Foote |first=Sheila |date=16 October 1995}}</ref> a $1.9-billion five-year contract was signed in August 1996 to upgrade 232 AH-64As into AH-64Ds.<ref>{{cite news |url=http://www.accessmylibrary.com/article-1G1-18589330/army-inks-1-9.html |archive-url=https://archive.today/20120723085951/http://www.accessmylibrary.com/article-1G1-18589330/army-inks-1-9.html |url-status=dead |archive-date=23 July 2012 |title=Army Inks $1.9 Billion AH-64D Apache Deal |work=Defense Daily |last=Caires |first=Greg |date=19 August 1996}}</ref> On 17 March 1997, the first production AH-64D flew. It was delivered on 31 March.<ref>Eden, Paul, ed. "Boeing AH-64 Apache". ''Encyclopedia of Modern Military Aircraft''. Amber Books, 2004. {{ISBN|1-904687-84-9}}.</ref>

[[File:RNLAF AH-64 Apache at the Oirschotse Heide Low Flying Area (36570605232).jpg|thumb|RNLAF AH-64 Apache in flight]]
Portions of the Apache are produced by other aerospace firms. [[AgustaWestland]] has produced a number of components for the Apache both for the international market and for the [[British Army]]'s [[AgustaWestland Apache]].<ref name ='brit comp'>{{cite news |url=http://news.bbc.co.uk/1/hi/8594402.stm |title=Ensure Israel arms curbs, say MPs |work=BBC News |date=30 March 2010}}</ref> Since 2004, [[Korea Aerospace Industries]] has been the sole manufacturer of the Apache's fuselage.<ref>{{cite web |url=http://findarticles.com/p/articles/mi_6712/is_33_217/ai_n28996439/ |title=KAI Signs Cooperation Agreement With Boeing, To Produce Apache Fuselages |publisher=Defense Daily |date=20 February 2003 |url-status=dead |archive-url=https://web.archive.org/web/20150904034814/http://findarticles.com/p/articles/mi_6712/is_33_217/ai_n28996439/ |archive-date= 4 September 2015 }}</ref><ref>{{cite web |url=http://www.koreaaero.com/english/business/fuselage_01.asp |title=F-15/Apache Fuselage Monopolization Program |publisher=Korea Aerospace Industries |access-date=21 January 2012 |archive-url=https://web.archive.org/web/20170809130914/http://www.koreaaero.com/english/business/fuselage_01.asp |archive-date=9 August 2017 |url-status=dead }}</ref><ref>{{cite web |last=Dunbar |first=Lisa |url=http://www.boeing.com/apachenews/2009/issue_01/news_s1_p2.html |title=Boeing celebrates milestone: 100th AH-64D Apache fuselage delivery |publisher=Boeing |year=2009 |url-status=dead |archive-url=https://web.archive.org/web/20120220081818/http://www.boeing.com/apachenews/2009/issue_01/news_s1_p2.html |archive-date=20 February 2012}}</ref> Fuselage production had previously been performed by [[Teledyne Ryan Aeronautical]]. The transfer of fuselage production led to a prolonged legal dispute between Teledyne Ryan and Boeing.<ref>{{cite web |url=http://www.flightglobal.com/news/articles/arbitrator-will-rule-on-ah-64-fuselage-production-dispute-35308/ |title=Arbitrator will rule on AH-64 fuselage production dispute |website=FlightGlobal |date=8 April 1998}}</ref>

The AH-64D program cost a total of $11 billion (~${{Format price|{{Inflation|index=US-GDP|value=11000000000|start_year=2007}}}} in {{Inflation/year|US-GDP}}) through 2007.<ref>{{cite web |url=http://www.deagel.com/Combat-Helicopters/AH-64D-Apache-Longbow_a000519003.aspx |title=AH-64D Apache Longbow |publisher=Deagel.com |access-date=28 October 2010}}</ref> In April 2006, Boeing was awarded a $67.6 million (~${{Format price|{{Inflation|index=US-GDP|value=67600000|start_year=2006}}}} in {{Inflation/year|US-GDP}}) fixed-price contract for the remanufacture of several existing U.S. AH-64As to the AH-64D configuration. Between May 2009 and July 2011, a further five contracts were issued to remanufacture batches of AH-64As into AH-64Ds.<ref>{{cite web |url=http://www.defenseindustrydaily.com/115b-contract-to-remanufacture-129-apaches-to-ah64d-longbow-configuration-02972/ |title=Boeing Remanufactures AH-64A Apaches to AH-64D Block II |publisher=defenseindustrydaily.com |date=21 July 2011}}</ref> Since 2008, nations operating the older Apaches have been urged to undertake modernization programs as support for the AH-64A is withdrawn.<ref>{{cite web |first=Craig |last=Hoyle |url=http://www.flightglobal.com/articles/2008/10/15/317276/greece-urged-to-commit-to-apache-upgrade-as-air-force-eyes-new-utility.html |title=Greece urged to commit to Apache upgrade, as air force eyes new utility model |website=FlightGlobal |date=15 October 2008}}</ref>

By May 2019, Boeing tested in a [[wind tunnel]] a [[Compound helicopter|compound]] Apache scale model with a [[pusher propeller]], a small wing to increase range and speed, and a counter-torque [[tail rotor]] like the cancelled [[Lockheed AH-56 Cheyenne]] of the 1960s.<!--<ref name=Flight17may2019>--> It competed for the U.S. Army's [[Future Long Range Assault Aircraft]] (FLRAA) unveiled in April, developed from the [[Future Vertical Lift]] Capability Set 3 (medium rotorcraft) without the attack requirement, while the U.S. Army's [[Future Attack Reconnaissance Aircraft|FARA]] should replace the retired [[Bell OH-58 Kiowa]] scout and up to half of the AH-64 fleet.<ref name=Flight17may2019>{{cite news |url= https://www.flightglobal.com/news/articles/boeing-suggests-propulsor-winged-ah-64-apache-varia-458248/ |title= Boeing suggests propulsor, winged AH-64 Apache variant for US Army |date= 17 May 2019 |author= Garrett Reim |website=FlightGlobal}}</ref>