Editing Bell AH-1 Cobra (section)

==Development==

===Background===
Closely related to the development of the Bell AH-1 is the story of the [[Bell UH-1 Iroquois]] transport helicopter—an icon of the [[Vietnam War]] and one of the most numerous helicopter types built. The UH-1 made the theory of [[air cavalry]] practical, as the new tactics called for US forces to be highly mobile across a wide area. Unlike before, they would not stand and fight long [[battle]]s, and they would not stay and hold positions. Instead, the plan was that the troops carried by fleets of UH-1 "Hueys" would range across the country, to fight the enemy at times and places of their own choice.<ref name=Wheeler_p62-4>Wheeler 1987, pp. 62–64.</ref>

The massive expansion of American military presence in Vietnam opened a new era of war from the air. The linchpin of US Army tactics was the helicopters, and the protection of those helicopters became a vital role.<ref name=Wheeler_p60-1>Wheeler 1987, pp. 60–61.</ref> It became clear that unarmed troop helicopters were vulnerable against ground fire from [[Viet Cong]] and [[North Vietnamese Army|North Vietnamese]] troops, particularly as they approached landing zones to disembark or embark troops. Without friendly support from artillery or ground forces, the only way to pacify a landing zone was from the air, preferably with an aircraft that could closely escort the transport helicopters, and loiter over the landing zone as the battle progressed. By 1962, a small number of armed UH-1As were used as escorts, armed with multiple machine guns and rocket mounts.<ref name=Wheeler_p57-62>Wheeler 1987, pp. 57–62, 64–65.</ref> However, these makeshift gunships came with considerable tradeoffs, particularly being barely able to keep up with the troop transports they were intended to protect.<ref name= "cobra birth">{{cite web |url= https://www.smithsonianmag.com/air-space-magazine/13_aug2017-birth-of-the-cobra-180963930/ |title= Birth of the Cobra |publisher= Smithsonian Magazine |date= August 2017 |first= Stephen |last= Joiner}}</ref>

While some officials within the Pentagon, particularly those within the US Army, had recognized the potential value of purpose-built armed rotary aircraft as early as 1962 and were keen to see such a vehicle developed promptly, the issue was complicated in part due to inter-service politics.<ref name= "cobra birth"/> The [[United States Air Force]] (USAF) largely held the opinion that most forms of US military aircraft should be operated only by their service, and that the US Army would be intruding into their domain by developing a complex armed aerial combatant, and ought to be largely restricted to transport aircraft. Meanwhile, some Army officials were concerned that the USAF did not take the [[close air support]] (CAS) mission as seriously as it ought to, and that response times of 30 minutes or more for fixed-wing aircraft would be unacceptable.<ref name= "cobra birth"/>

===Iroquois Warrior, Sioux Scout and AAFSS===
{{main|Bell 207 Sioux Scout}}
[[File:Bell 207 Sioux Scout 73923 (cropped).jpg|thumb|Bell Model 207 Sioux Scout]]

Bell had been investigating helicopter gunships since the late 1950s, paying particular attention to the [[Algerian War]], in which French forces mounted weapons onto helicopters to fight the growing insurgency.<ref name= "cobra birth"/> The company created a mockup of its D-255 helicopter gunship concept, named "Iroquois Warrior". The Iroquois Warrior was planned to be a purpose-built attack aircraft based on UH-1B components with a new, slender airframe and a two-seat, tandem cockpit. It featured a grenade launcher in a ball turret on the nose, a 20&nbsp;mm belly-mounted gun pod, and stub wings for mounting rockets or [[SS.10]] anti-tank missiles.<ref name=Verier_p12-7>Verier 1990, pp. 12–17.</ref>

In June 1962, Bell displayed the mockup to US Army officials, hoping to solicit funding for further development; rival manufacturers issued protests to this approach, alleging that it was an attempt by Bell to circumvent the competitive process.<ref name=Verier_p12-7/><ref name= "cobra birth"/> Nevertheless, the Army was interested and awarded Bell a proof-of-concept contract in December 1962. Bell modified a [[Bell 47|Model 47]] into the [[Bell 207 Sioux Scout|Model 207 Sioux Scout]] which first flew in July 1963. The Sioux Scout had all the key features of a modern attack helicopter: a tandem [[Cockpit (aviation)|cockpit]], stub wings for weapons, and a chin-mounted [[gun turret]]. After evaluating the Sioux Scout in early 1964, the Army was impressed but also felt that it was undersized, underpowered, and that the Sioux Scout was generally not suited for practical operations.<ref name=Donald>Donald and March 2004, {{page needed|date=January 2021}}.</ref>

The Army's solution to the shortcomings of the Sioux Scout was to launch the [[Advanced Aerial Fire Support System]] (AAFSS) competition.<ref name=Donald/> This called for a heavily armed helicopter capable of at least {{convert|200|mph}}. A total of seven companies, including Bell, opted to respond to the requirement.<ref name= "cobra birth"/> It was out of the AAFSS program that the [[Lockheed AH-56 Cheyenne]] emerged, a heavy attack helicopter with high speed capability. During testing, it proved to be too sophisticated and costly, and was ultimately canceled in 1972 after ten years of development. In its place, the [[Advanced Attack Helicopter]] program was launched. Under this initiative, the Army sought a conventional attack helicopter with a greater level of survivability.<ref name=Donald/>

===Model 209===
Despite the Army's preference for the AAFSS program—for which Bell Helicopter was not selected to compete—the company persisted with their own idea of a smaller and lighter gunship, noting that Lockheed had little experience in developing rotorcraft and correctly predicted that it would encounter considerable difficulties.<ref name=Donald/><ref name= "cobra birth"/> Bell employee Mike Folse played a key role in developing this new gunship, which he intentionally based around the existing UH-1 on the rationale that, while the Army could not purchase a completely original helicopter without a formal design competition, the service was able to procure a modification of an aircraft that was already in its inventory without invoking such hurdles. This initiative quickly caught the approval of Bell's senior management team.<ref name= "cobra birth"/>

In January 1965, Bell elected to invest $1 million (equivalent to ${{Format price|{{Inflation|index=US-GDP|value=1000000|start_year=1965}}}} in {{Inflation/year|US-GDP}}) to proceed with the concept's detailed design. Mating the proven transmission, the "540" rotor system of the UH-1C augmented by a Stability Control Augmentation System (SCAS), and the T53 turboshaft engine of the UH-1 with the design philosophy of the Sioux Scout, Bell produced the ''Model 209''.<ref name=Donald/> It largely resembled the "Iroquois Warrior" mockup,<ref name=Huey_Cobra>Bishop 2006, {{page needed|date=January 2021}}.</ref> particularly in its cockpit and tail boom; in broad visual terms, there was relatively little shared between the proposed design and the UH-1. Despite appearance, much of the Model 209's major elements, such as the tail rotor and much of the dynamic systems, were identical. Roughly 80 percent of its components already had existing Huey part numbers.<ref name= "cobra birth"/>

[[File:Bell 209.jpg|thumb|left|Bell 209 prototype of the AH-1 Cobra series, with skids retracted (FAA no. N209J)]]
On 3 September 1965, Bell rolled out its Model 209 prototype, and four days later it made its maiden flight, only eight months after the project's go-ahead and slightly under budget.<ref name= "cobra birth"/> This first flight was witnessed by around 20 US Army officials, the service having had no awareness of the project's existence prior to this, and rapidly drew the government's attention. One early test flight was met with a reportedly enthusiastic visit by US secretary of defense [[Robert McNamara]]. Bell claimed at this phase of the project that production units could be ready for service within one year.<ref name= "cobra birth"/>

As the Vietnam War proceeded, pressure accumulated in favor of the Model 209. Attacks on US forces were increasing and, by the end of June 1965, there were already 50,000 US ground troops in Vietnam.<ref name=Donald/> 1965 was also the deadline for AAFSS selection, but the program would become stuck in technical difficulties and political bickering. The US Army needed an interim gunship for Vietnam and it approached five separate companies with its request to provide a quick solution. Submissions came in for armed variants of the [[Boeing CH-47 Chinook#ACH-47A|Boeing-Vertol ACH-47A]], [[Kaman SH-2 Seasprite#Variants|Kaman HH-2C Tomahawk]], [[Piasecki 16H Pathfinder]], [[Sikorsky S-61]], and the Bell 209.<ref name=Donald/><ref name= "cobra birth"/>

During April 1966, Bell's submission emerged victorious in an evaluation against the other rival helicopters. The US Army promptly signed the first production contract, ordering an initial batch of 110 aircraft.<ref name=Donald/><ref name= "McGowen 107">McGowen 2005, p. 107.</ref> By the end of the year, rapid follow-on orders had increased this to 500 Cobras.<ref name= "cobra birth"/> Bell added "Cobra" to the UH-1's Huey nickname to produce its ''HueyCobra'' name for the 209. The Army applied the ''Cobra'' name to its AH-1G designation for the helicopter.<ref>Verier 1990, pp. 30–31.</ref> The Bell 209 demonstrator was used for the next six years to test weapons and fit of equipment. An additional use for the demonstrator was participating in marketing initiatives.<ref name= "cobra birth"/> It was also modified to match the AH-1 production standard by the early 1970s. The demonstrator was retired to the [[General George Patton Museum of Leadership|Patton Museum]] at [[Fort Knox]], Kentucky and converted to approximately its original appearance.<ref name=Huey_Cobra/>

===Into production===
The Bell 209 design was modified in several respects for production. The retractable skids were replaced by simpler fixed skids; this was not due to any recorded design flaw or serviceability, but it was feared that the landing gear bay could become inundated with mud.<ref name= "cobra birth"/> Furthermore, a new wide-chord rotor blade was adopted. It was also decided that a plexiglass canopy should replace the Model 209's armored glass canopy, which was heavy enough to negatively impact performance.<ref name=Huey_Cobra/><ref name= "McGowen 158">McGowen 2005, p. 158.</ref> The umbrella-shaped [[dive brake]] was deleted, having reportedly self-destructed during its first test flight.<ref name= "cobra birth"/>

Numerous changes of the design were incorporated after the Cobra had entered service. The principal amongst these changes was the repositioning of the tail rotor from the helicopter's left side to the right, which facilitated an increase in the effectiveness of the tail rotor.<ref>Verier 1990, p. 44.</ref> The AH-1 was the first U.S. Army helicopter not named for a Native American people since the practice began with the [[Bell H-13 Sioux|H-13 Sioux]] and continued with the UH-1 Iroquois, AH-56 Cheyenne, OH-58 Kiowa, and later helicopters.<ref>{{Cite web |url=https://medium.com/war-is-boring/everyone-relax-the-armys-native-american-helicopter-names-are-not-racist-d21beb55d782 |title=Everyone Relax—The Army's Native American Helicopter Names Are Not Racist |publisher=War Is Boring |date=1 July 2014 |website=Medium.com}}</ref>

Within its first decade of service, the US Army had put the original Cobra model through various exercises and operations, which highlighted both the attack helicopter's promise and areas in which it could be improved.<ref name= "McGowen 1578">McGowen 2005, pp. 157-158.</ref> By 1972, the US Army openly sought an improved anti-armor capability. Under the Improved Cobra Armament Program (ICAP), trials of eight AH-1s fitted with [[BGM-71 TOW|TOW missiles]] were conducted in October 1973. After passing qualification tests the following year, Bell was contracted with upgrading 101 AH-1Gs to the TOW-capable AH-1Q configuration.<ref>[http://www.history.army.mil/books/DAHSUM/1974/ch11.htm RD&A, Sect 135] {{Webarchive|url=https://web.archive.org/web/20170710102319/http://www.history.army.mil///books/DAHSUM/1974/ch11.htm |date=10 July 2017}} – Army Historical Summary: FY74.</ref> While early-production examples were not compatible with [[night vision goggles]], the cockpit instrumentation of later Cobras was altered to facilitate their use.<ref name= "cobra birth"/>

Further variants of the Cobra were promptly developed, with both new-build models and early production examples being modified to incorporate the improvements. During March 1978, the US Army opted to procure a batch of 100 new-build Cobras that featured a new T-shaped instrument panel, improved [[Composite material|composite]] rotor blades, revised transmission and gearboxes, the M128 helmet-mounted sight, and the M28A3 armament system.<ref name= "McGowen 1589">McGowen 2005, pp. 158-159.</ref> A major feature was the adoption of a more powerful version of the T53 engine. Designated AH-1S, the Cobra was upgraded in three stages, culminating with the AH-1F.<ref name=Donald/><ref>Verier 1990, pp. 57, 59–61.</ref><ref name= "McGowen 1596">McGowen 2005, pp. 159-160.</ref> The AH-1F integrated numerous countermeasures, including an infrared jammer, a radar jammer, and a hot plume exhaust suppressor.<ref name= "cobra birth"/>

The U.S. Marine Corps (USMC) quickly became interested in the Cobra, opting to order an improved twin-engine version in 1968 under the designation AH-1J.<ref name= "McGowen 108">McGowen 2005, p. 108.</ref>  During the early 1970s, the USMC proceeded to order an upgraded model, the AH-1T, which featured dynamic elements derived from the abortive [[Bell 309 KingCobra]]; as such, it featured a longer fuselage and tailboom. These dynamic changes were combined with the adoption of heavier armaments, which provided the USMC with an effective anti-armor capacity, unlike the preceding model.<ref name= "McGowen 160">McGowen 2005, p. 160.</ref> The USMC's interest in the Cobra would lead to the production of more [[AH-1 SuperCobra|twin-engine variants]] of the helicopter.<ref>Verier 1990, pp. 86–88.</ref>