Editing McDonnell Douglas F/A-18 Hornet (section)

==Development==

===Origins===
{{main|VFAX|Lightweight Fighter program|Northrop YF-17}}
[[File:YF-16 and YF-17 in flight.jpg|thumb|left|YF-16 and YF-17 prototypes being tested by the U.S. Air Force]]

The United States Navy started the Naval Fighter-Attack, Experimental ([[VFAX]]) program to procure a multirole aircraft to replace the [[Douglas A-4 Skyhawk]], the [[LTV A-7 Corsair II|A-7 Corsair II]], and the remaining [[McDonnell Douglas F-4 Phantom II]]s, and to complement the [[Grumman F-14 Tomcat]]. Vice Admiral [[Kent Lee]], then head of [[Naval Air Systems Command]], was the lead advocate for the VFAX against strong opposition from many Navy officers, including Vice Admiral [[William D. Houser]], deputy chief of naval operations for air warfare – the highest-ranking naval aviator.<ref name=Kelly_Inside_Story>Kelly, Orr. ''Hornet: the Inside Story of the F/A-18''. Novato, California: Presidio Press, 1990. {{ISBN|978-0-89141-344-8}}.</ref>

In August 1973, Congress mandated that the Navy pursue a lower-cost alternative to the F-14. [[Grumman]] proposed a stripped F-14 designated the F-14X, while [[McDonnell Douglas]] proposed a naval variant of the [[McDonnell Douglas F-15 Eagle|F-15]], but both were nearly as expensive as the F-14.<ref name=Jenkins_p19>Jenkins 2000, pp. 19–21.</ref>  That summer, [[United States Secretary of Defense|Secretary of Defense]] [[James R. Schlesinger]] ordered the Navy to evaluate the competitors in the Air Force's [[Lightweight Fighter program|Lightweight Fighter]] (LWF) program, the [[General Dynamics]] [[General Dynamics F-16 Fighting Falcon|YF-16]] and [[Northrop YF-17]].<ref name=Navy_History_Hornet>[http://www.history.navy.mil/planes/fa18.htm "F/A-18 Hornet and F/A-18 Super Hornet."] {{webarchive|url=https://web.archive.org/web/20141217024406/http://www.history.navy.mil/planes/fa18.htm |date=17 December 2014}} ''U.S. Navy''. Retrieved: 4 July 2008.</ref>  The Air Force competition specified a day fighter with no strike capability. In May 1974, the House Armed Services Committee redirected $34&nbsp;million from the VFAX to a new program, the Navy Air Combat Fighter (NACF),<ref name=Navy_History_Hornet/> intended to make maximum use of the technology developed for the LWF program.<ref name=Jenkins_p19/>

===Redesigning the YF-17===
Though the YF-16 won the LWF competition, the Navy was skeptical that an aircraft with one engine and narrow landing gear could be easily or economically adapted to carrier service, and refused to adopt an F-16 derivative. On 2 May 1975, the Navy announced its selection of the YF-17.<ref>Donald, David ed. "Boeing F/A-18 Hornet". ''Warplanes of the Fleet''. London: AIRtime, 2004. {{ISBN|978-1-880588-81-9}}.</ref> Since the LWF did not share the design requirements of the VFAX, the Navy asked McDonnell Douglas and Northrop to develop a new aircraft from the design and principles of the YF-17. On 1 March 1977, Secretary of the Navy W. Graham Claytor announced, that the F-18 would be named "Hornet", after the characteristics of the Hornet insect. It also shares the namesake with ships that had borne the name {{USS|Hornet}} since the [[American Revolutionary War|Revolutionary War]].<ref name=Jenkins_p19/><ref>{{Cite book |chapter-url=https://books.google.com/books?id=2r63AAAAIAAJ&pg=RA1-PA9 |title=Naval Aviation News 1978 |publisher=Chief of Naval Operations and Naval Air Systems Command, Navy Department |year=1978 |editor-last=Rause |editor-first=Cdr. Rosario |pages=9 |chapter=February 1978}}</ref>

[[File:Northrop YF-17 Cobra - in flight.jpg|thumb|The [[Northrop YF-17 Cobra]] was developed into the carrier-capable F/A-18.]]
Northrop had partnered with McDonnell Douglas as a secondary contractor on NACF to capitalize on the latter's experience in building carrier aircraft, including the widely used F-4 Phantom II. On the F-18, the two companies agreed to evenly split component manufacturing, with McDonnell Douglas conducting the final assembly. McDonnell Douglas would build the wings, [[stabilator]]s, and forward fuselage; while Northrop would build the center and aft fuselage and vertical stabilizers. McDonnell Douglas was the prime contractor for the naval versions, and Northrop would be the prime contractor for the F-18L land-based version which Northrop hoped to sell on the export market.<ref name=Jenkins_p19/><ref name=Navy_History_Hornet/>

The F-18, initially known as McDonnell Douglas Model 267, was drastically modified from the YF-17. For carrier operations, the airframe, undercarriage, and [[tailhook]] were strengthened, folding wings and catapult attachments were added, and the landing gear was widened. Another wheel was added to the front landing gear as well.<ref name=Jenkins_p22>Jenkins 2000, pp. 22–26.</ref> To meet Navy range and reserves requirements, McDonnell increased fuel capacity by {{convert|4460|lb|kg|sigfig=3}}, by enlarging the dorsal spine and adding a 96-gallon fuel tank to each wing. A "snag" was added to the wing's [[leading edge]] and stabilators to prevent an [[aeroelastic flutter]] discovered in the F-15 stabilator. The wings and stabilators were enlarged, the aft fuselage widened by {{convert|4|in|mm|sigfig=3}}, and the engines canted outward at the front. These changes added {{convert|10000|lb|kg|sigfig=3|abbr=on}} to the gross weight, bringing it to {{convert|37000|lb|kg|sigfig=3|abbr=on}}. The YF-17's control system was replaced with a fully digital [[fly-by-wire]] system with quadruple redundancy, the first to be installed in a production fighter. The airframe was designed for a service life of 6,000 flight hours.<ref name="service_life"/><ref name=Jenkins_p22/>

[[File:First YF-18A Hornet on display in 1978.JPG|thumb|First preproduction F-18A in October 1978]]
Originally, plans were to acquire a total of 780 aircraft of three variants: the single-seat F-18A fighter and A-18A attack aircraft, differing only in avionics, and the dual-seat TF-18A, which retained full mission capability of the F-18 with a reduced fuel load.<ref name=FedAmSci/> Following improvements in avionics and multifunction displays, and a redesign of external stores stations, the A-18A and F-18A were able to be combined into one aircraft.<ref name=Jenkins_p19/> Starting in 1980, the aircraft began to be referred to as the F/A-18A, and the designation was officially announced on 1 April 1984. The TF-18A was redesignated F/A-18B.<ref name=Jenkins_p19/>

=== Northrop's F-18L ===
Northrop developed the F-18L as a potential export aircraft. Since it was not strengthened for carrier service, it was expected to be lighter and better performing, and a strong competitor to the [[General Dynamics F-16 Fighting Falcon|F-16 Fighting Falcon]] then being offered to American allies. The F-18L's normal [[gross weight]] was lighter than the F/A-18A by {{convert|7700|lb|kg|sigfig=3}}, via lighter landing gear, lack of wing folding mechanism, reduced part thickness in areas, and lower fuel-carrying capacity. Though the aircraft retained a lightened tailhook, the most obvious external difference was the removal of "snags" on the leading edge of the wings and stabilators. It still retained 71% commonality with the F/A-18 by parts weight, and 90% of the high-value systems, including the avionics, radar, and [[electronic countermeasure]] suite, though alternatives were offered. Unlike the F/A-18, the F-18L carried no fuel in its wings and lacked weapons stations on the intakes. It had three underwing pylons on each side, instead.<ref name=Jenkins_p26>Jenkins 2000, pp. 26–29.</ref>

The F/A-18L version followed to coincide with the U.S. Navy's F/A-18A as a land-based export alternative. This was essentially an F/A-18A lightened by about {{convert|2500|to|3000|lb|kg|sigfig=3}}; weight was reduced by removing the folding wing and associated actuators, implementing a simpler landing gear (single wheel nose gear and [[cantilever]] oleo main gear), and changing to a land-based tail hook. The revised F/A-18L included wing fuel tanks and fuselage stations of the F/A-18A. Its weapons capacity would increase from {{convert|13700|to|20000|lb|kg|sigfig=3}}, largely due to the addition of a third underwing pylon and strengthened wingtips (11 stations in total vs 9 stations of the F/A-18A). Compared to the F-18L, the outboard weapons pylons are closer to the wingtip missile rails. Because of the strengthened nonfolding wing, the wingtip missile rails were designed to carry either the [[AIM-7 Sparrow]] (7F/7M/7P variants, same as the F/A-18A) or [[Skyflash]] medium-range air-to-air missiles, in addition to the [[AIM-9 Sidewinder]] as found on the F/A-18A. The F/A-18L was strengthened for a 9 g design load factor compared to the F/A-18A's 7.5 g factor.<ref>Northrop F/A-18L design brochure 1978.</ref>

The partnership between McDonnell Douglas and Northrop soured over competition for foreign sales for the two models. Northrop felt that McDonnell Douglas would put the F/A-18 in direct competition with the F-18L. In October 1979, Northrop filed a series of lawsuits charging that McDonnell was using Northrop technology developed for the F-18L for foreign sales of the F/A-18 in violation of their agreement, and asked for a moratorium on foreign sales of the Hornet. McDonnell Douglas countersued, alleging Northrop illegally used F/A-18 technology in its [[Northrop F-20 Tigershark|F-20 Tigershark]]. A settlement was announced 8 April 1985 for all of the lawsuits.<ref name="Los Angeles Times">{{cite web|url=https://www.latimes.com/archives/la-xpm-1985-04-09-fi-28110-story.html|title=McDonnell Settles Suit by Northrop for $50 Million|first=KATHLEEN|last=DAY|date=9 April 1985|website=Articles.latimes.com|access-date=10 April 2018|archive-url=https://web.archive.org/web/20171011185426/http://articles.latimes.com/1985-04-09/business/fi-28110_1_mcdonnell-douglas|archive-date=11 October 2017|url-status=live}}</ref><ref name="nytimes.com">{{cite news |title=McDonnell, Northrop Suit The McDonnell Douglas Corporation and the Northrop Corporation yesterday announced |url=https://www.nytimes.com/1985/04/09/business/mcdonnell-northrop-suit-mcdonnell-douglas-corporation-northrop-corporation.html |date=9 April 1985 |newspaper=The New York Times |access-date=4 September 2017 |archive-url=https://web.archive.org/web/20170810132945/http://www.nytimes.com/1985/04/09/business/mcdonnell-northrop-suit-mcdonnell-douglas-corporation-northrop-corporation.html |archive-date=10 August 2017 |url-status=live }}</ref><ref name="washingtonpost.com">{{cite web|url=https://www.washingtonpost.com/archive/business/1985/04/09/mcdonnell-douglas-northrop-settle-jet-feud/736cb2c3-466f-49e1-8c24-7b248911cf71/|title=McDonnell Douglas, Northrop Settle Jet Feud|date=9 April 1985|access-date=10 April 2018|website=Washingtonpost.com|archive-url=https://web.archive.org/web/20171018115242/https://www.washingtonpost.com/archive/business/1985/04/09/mcdonnell-douglas-northrop-settle-jet-feud/736cb2c3-466f-49e1-8c24-7b248911cf71/|archive-date=18 October 2017|url-status=live}}</ref><ref name="books.google.com">{{cite book |first=Orr |last=Kelly |title=Hornet: The Inside Story of the F/A-18 |url=https://books.google.com/books?id=BdG1AwAAQBAJ&pg=PT113 |year=2014 |publisher=Open Road Media |isbn=978-1-4976-4567-7 |page=113}}</ref> McDonnell Douglas paid Northrop $50&nbsp;million for "rights to sell the F/A-18 wherever it could".<ref name="books.google.com"/> Additionally, the companies agreed on McDonnell Douglas as the prime contractor with Northrop as the principal subcontractor.<ref name="Los Angeles Times"/><ref name="nytimes.com"/><ref name="washingtonpost.com"/><ref name="books.google.com"/> As principal subcontractor, Northrop produced the rear section for the F/A-18 (A/B/C/D/E/F), while McDonnell Douglas produced the rest with final assembly performed by McDonnell Douglas.<ref>{{cite web|url=http://www.northropgrumman.com/Capabilities/FA18EFSuperHornet/Pages/default.aspx|title=F/A-18 E/F Super Hornet|website=Northrop Grumman|access-date=10 April 2018|archive-url=https://web.archive.org/web/20180331182635/http://www.northropgrumman.com/Capabilities/FA18EFSuperHornet/Pages/default.aspx|archive-date=31 March 2018|url-status=live}}</ref> At the time of the settlement, Northrop had ceased work on the F-18L. Most export orders for the F-18L were captured by the F-16 or the F/A-18.<ref name=Jenkins_p26/> The F-20 Tigershark did not enter production, and although the program was not officially terminated until 17 November 1986, it was dead by mid-1985.<ref>{{cite web|url=http://www.joebaugher.com/usaf_fighters/f5_51.html|title=Northrop F-5G/F-20A Tigershark|website=Joebaugher.com|access-date=10 April 2018|archive-url=https://web.archive.org/web/20171113073150/http://www.joebaugher.com/usaf_fighters/f5_51.html|archive-date=13 November 2017|url-status=live}}</ref>

===Into production===
[[File:FA-18-NAVY-Blue-Diamond.jpg|thumb|left|U.S. Navy F/A-18C during Operation Enduring Freedom in 2002|alt=Overall-gray jet fighter, with red, blue and white-tipped nose, is overflying sea and scattered white clouds down below. The aircraft is carrying streamlined external fuel tanks and missiles under its wings, and is heading right.]]

During flight testing, the snag on the leading edge of the stabilators was filled in, and the gap between the [[leading-edge extension]]s (LEX) and the fuselage was mostly filled in. The gaps, called the [[boundary layer]] air discharge slots, controlled the vortices generated by the LEX and presented clean air to the vertical stabilizers at high [[Angle of attack|angles of attack]], but they also generated a great deal of [[parasitic drag]], worsening the problem of the F/A-18's inadequate range. McDonnell filled in 80% of the gap, leaving a small slot to [[bleed air]] from the engine intake. This may have contributed to early problems with fatigue cracks appearing on the vertical stabilizers due to extreme [[structural load]]s, resulting in a short grounding in 1984 until the stabilizers were strengthened. Starting in May 1988, a small vertical fence was added to the top of each LEX to broaden the vortices and direct them away from the vertical stabilizers. This also provided a minor increase in controllability as a side effect.<ref name=Jenkins_p35>Jenkins 2000, p. 35.</ref> F/A-18s of early versions had a problem with insufficient rate of roll, exacerbated by the insufficient wing stiffness, especially with heavy underwing ordnance loads. The first production F/A-18A flew on 12 April 1980. After a production run of 380 F/A-18As<ref name=Boeing_Milestones/> (including the nine assigned to flight systems development), manufacture shifted to the F/A-18C in September 1987.<ref name=FedAmSci/>

===Improvements and design changes===
In the 1990s, the U.S. Navy faced the need to replace its aging [[A-6 Intruder]]s and A-7 Corsair IIs with no replacement in development.<ref name=Donald_p45>Donald 2004, p. 45.</ref> To answer this deficiency, the Navy commissioned development of the [[Boeing F/A-18E/F Super Hornet|F/A-18E/F Super Hornet]]. Despite its designation, it is not just an upgrade of the F/A-18 Hornet, but rather, a new, larger airframe using the design concepts of the Hornet. Hornets and Super Hornets will serve complementary roles in the U.S. Navy carrier fleet until the Hornet A-D models are completely replaced by the [[Lockheed Martin F-35 Lightning II|F-35C Lightning II]].  Although the airframe was originally designed for service life of 6,000 flight hours, the Marines have chosen to extend the use of certain F/A-18s up to 10,000 flight hours, due to delays in the F-35B variant.<ref name="service_life">Munoz, Carlo. [http://defense.aol.com/2011/09/29/navy-marines-eye-jsf-funds-for-hornet-life-extension/ "Navy, Marines Eye JSF Dough to Keep F-18s Flying."] {{Webarchive|url=https://web.archive.org/web/20111007102633/http://defense.aol.com/2011/09/29/navy-marines-eye-jsf-funds-for-hornet-life-extension/ |date=7 October 2011 }} ''AOL Defense'', 29 September 2011.</ref>