Bell AH-1

Bell AH-1 Cobra par Wikipedia.en

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The Bell AH-1 Cobra (company designation: Model 209) is a two-bladed, single engine [Vous devez être inscrit et connecté pour voir ce lien] manufactured by [Vous devez être inscrit et connecté pour voir ce lien]. It shares a common [Vous devez être inscrit et connecté pour voir ce lien], [Vous devez être inscrit et connecté pour voir ce lien] and [Vous devez être inscrit et connecté pour voir ce lien] system with the older [Vous devez être inscrit et connecté pour voir ce lien]. The AH-1 is also referred to as the HueyCobra or Snake.

The AH-1 was the backbone of the [Vous devez être inscrit et connecté pour voir ce lien]'s attack helicopter fleet, but has been replaced by the [Vous devez être inscrit et connecté pour voir ce lien] in Army service. Upgraded versions continue to fly with the militaries of several other nations.

The [Vous devez être inscrit et connecté pour voir ce lien] remain in service with [Vous devez être inscrit et connecté pour voir ce lien] as the service's primary attack helicopter. Surplus AH-1 helicopters have been converted for fighting forest fires. The [Vous devez être inscrit et connecté pour voir ce lien] refers to their program as the Firewatch Cobra. Garlick Helicopters also converts surplus AH-1s for forest firefighting under the name, FireSnake.[Vous devez être inscrit et connecté pour voir ce lien]

Development


Background


Closely related with the development of the Bell AH-1 is the story of the [Vous devez être inscrit et connecté pour voir ce lien]—predecessor of the modern helicopter, icon of the [Vous devez être inscrit et connecté pour voir ce lien] and still one of the most numerous helicopter types in service today.

The UH-1 made the theory of air [Vous devez être inscrit et connecté pour voir ce lien] 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 [Vous devez être inscrit et connecté pour voir ce lien], 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.

It soon became clear that the unarmed troop helicopters were vulnerable against ground fire from [Vous devez être inscrit et connecté pour voir ce lien] and [Vous devez être inscrit et connecté pour voir ce lien] troops, particularly as they came down to drop their troops in a landing zone.

Without friendly support from artillery or ground forces, the only way to pacify a landing zone was from the air, preferably with a machine 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.
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The massive expansion of [Vous devez être inscrit et connecté pour voir ce lien] military presence in Vietnam opened a new era of war from the air.

The linchpin of US Army tactics were the helicopters, and the protection of those helicopters became a vital role.

Iroquois Warrior and Sioux Scout

Bell had been investigating helicopter gunships since the late 1950s, and had created a mockup of its D 255 helicopter gunship concept, named "Iroquois Warrior".

In June 1962, Bell displayed the mockup to Army officials, hoping to solicit funding for further development.

The D 255 Iroquois Warrior was planned to be a purpose-built attack aircraft based on the 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 mm belly-mounted gun pod, and stub wings for mounting rockets or [Vous devez être inscrit et connecté pour voir ce lien].

Bell D-255 ( airframe UH-1C )

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The Army was interested and awarded Bell a proof of concept contract in December 1962. Bell modified a [Vous devez être inscrit et connecté pour voir ce lien] into the sleek [Vous devez être inscrit et connecté pour voir ce lien] Sioux Scout which first flew in July 1963.

^{[Vous devez être inscrit et connecté pour voir ce lien]} The Sioux Scout had all the key features of a modern helicopter gunship: a tandem [Vous devez être inscrit et connecté pour voir ce lien], stub wings for weapons, and a chin-mounted [Vous devez être inscrit et connecté pour voir ce lien].

After evaluating the Sioux Scout in early 1964, the Army was impressed, but also believed the Sioux Scout was too small, underpowered, unsophisticated, and fragile to be of practical use.

207 Sioux Scout

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AAFSS

Army's solution to the shortcomings of the Sioux Scout was to launch the Advanced Aerial Fire Support System (AAFSS) competition.

The AAFSS requirement would give birth to the [Vous devez être inscrit et connecté pour voir ce lien]–a heavy battlefield helicopter that would prove to be over-ambitious, over-complex and over-budget, before being canceled 10 years later in 1972.

The Cheyenne program developed future technology and demonstrated some impressive performance, but was never made to work as a functional gunship.

It served to underline an important rule of the combat helicopter–survival would be ensured only by the right mix of speed,
agility and weapons.

Cobra

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Model 209

At the same time, despite the Army's preference for the AAFSS–for which Bell Helicopter was not selected to compete–Bell stuck with their own idea of a smaller and lighter gunship.
In January 1965 Bell invested $1 million to proceed with a new 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.

^{[Vous devez être inscrit et connecté pour voir ce lien]} Bell's Model 209 largely resembled the "Iroquois Warrior" mockup.[Vous devez être inscrit et connecté pour voir ce lien]

In Vietnam, events were also advancing 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.
1965 was also the deadline for AAFSS selection, but the program would become stuck in technical difficulties and political bickering.

The U.S. Army needed an interim gunship for Vietnam and it asked five companies to provide a quick solution.

Submissions came in for armed variants of the [Vous devez être inscrit et connecté pour voir ce lien], [Vous devez être inscrit et connecté pour voir ce lien], [Vous devez être inscrit et connecté pour voir ce lien], [Vous devez être inscrit et connecté pour voir ce lien], and the Bell 209.