Introduction
The AH-1 Cobra, usually called the “Huey Cobra”, is an attack helicopter, designed by Bell Helicopter Textron. It shares a common engine, transmission and rotor system with the UH-1. It is now fully replaced by the AH-64 Apache in US Army service, but upgraded versions continue to fly with US Marine Corps and several other users.
Historical Information
Closely related with the development of the Bell AH-1 is the story of the Bell UH-1 – predecessor of the modern helicopter, icon of the Vietnam War and still one of the most numerous helicopter types in service today.
Bell’s XH-40 prototype first flew on 22 October 1956 and entered production in the same year as the HU-1A. The “HU” designation spawned the famous “Huey” nickname, although the re-alignment of US service designations in 1962 changed it into the familiar UH-1. 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 battles, and they would not stay and hold positions. Instead, the plan was that the troops carried by fleets of 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 UH-1 troop helicopters were not able to make opposed troop drops in the landing zones, but that heavy firepower would be needed to clear the Viet Cong and NVA troops out of the way.
By 1962 a small number of armed HU-1As (UH-1As) were escorting H-21 (CH-21) troop transports in and out of the landing zones, but the strict rules of engagement at the time prevented the gunships from operating effectively, as they could not fire until fired upon.
The massive expansion of American 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.
Sioux Scout
In December 1962 Bell had initiated a company-funded venture to provide a purpose-built gunship to US forces in Vietnam. The role of this new helicopter was to protect the troopships and to wield a full combat capability of its own. Bell’s first design was built around a modified Model 47, leading to the sleek Model 207 Sioux Scout which flew its maiden flight in July 1963.
The Sioux Scout had all the key features of a modern helicopter gunship – a tandem cockpit, stub wings for weapons and a chin-mounted gun turret. After evaluating the Sioux Scout in early 1964, the Army was impressed by it, but also believed that the Sioux Scout was too small, underpowered, unsophisticated and too fragile to be of practical use.
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 Lockheed AH-56 Cheyenne – a heavy battlefield helicopter that would prove to be over-ambitious, over-complex and over-budget, before being cancelled 10 years later in 1972. The Cheyenne programme 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.
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 the new Model 209 design. Mating the proven transmission, rotor system and the T53 turboshaft of the UH-1 with the design philosophy of the Sioux Scout, Bell produced the Model 209.
In Vietnam, events were also advancing in favour 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 programme was stuck in technical difficulties and political bickering. The US 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 Boeing-Vertol CH-47A, Kaman UH-2, Piasecki 16H Pathfinder, Sikorsky S-61 and the Bell 209.
On 3 September 1965 Bell rolled out the prototype Model 209, and four days later on 7 September it made its maiden flight, taking only eight months from the go-ahead. After the Model 209 had faced an evaluation against the other rival helicopters, in April 1966 the US Army signed the first production contract for 110 aircraft.
First Delivery
By June 1967, the first AH-1G HueyCobras had been delivered. Originally designated as UH-1H, the “A” for attack designation was soon adopted and when the improved UH-1D became the UH-1H, the HueyCobra became the AH-1G.
Bell built 1,116 AH-1Gs for the US Army between 1967 and 1973, and the Cobras chalked up over a million operational hours in Vietnam.
Operations
The Cobra is simpler to maintain than the Apache, and has a smaller shipboard footprint, two main reasons it remains in service with the Marine Corps. Its main usage is against armored targets. The Cobra’s narrow front gives it a defensive advantage making it a harder target to acquire.
Combat Experience
The AH-1 Cobras were in use during Tet of 1968 and were used extensively by the Army through the end of the Vietnam War. During the 1983 invasion of Grenada, the HueyCobra supported Marine operations on the island.
During Operation Desert Storm, the Cobras and SeaCobras deployed in a support role. Approximately 78 Marine Cobras flew 1,273 sorties with no combat losses and only one noncombat loss.
Cobra helicopter gunships were also used widely by the Israeli Air Force in Operation Peace for Galilee to destroy Syrian armor and fortification. The IAF Cobras destroyed dozens of Syrian armored fighting vehicles, including many of the modern Soviet T-72 main battle tank.
The Iraqi Mi-24s participated in air combat with Iranian AH-1J SeaCobras on several separate occasions during the Iran-Iraq War, ending favorably for the Iraqis with ten AH-1Js downed by Mi-24s compared to six Mi-24s downed by AH-1Js.
AH-1 Cobras are still used by the US military to this day, most notably in the ongoing Conflict in Iraq. AH-1 Cobras are also still used by the Israeli Air Force, with highly favorable reviews.
Single engined
* AH-1G HueyCobra
* JAH-1G HueyCobra (one armament test helicopter)
* TH-1G HueyCobra (dual-control trainers)
* Z.14 HueyCobra (Spanish navy designation of the AH-1G)
* AH-1Q
* AH-1R
* AH-1S
* AH-1P (redesignated Step 1 production standard AH-1S)
* AH-1E (redesignated Step 2 up-gunned AH-1S)
* AH-1F (redesignated Step 3 modernized AH-1S)
* Model 249
Twin engined
* AH-1J SeaCobra
* AH-1T Improved SeaCobra
* AH-1W SuperCobra
* AH-1Z SuperCobra
Users
* Bahrain
o AH-1E (12 in use)
o TAH-1P combat trainer (6 in use)
* Iran
o AH-1J (202 delivered)
* Israel
o AH-1S “Tzefa” צפע (approx. 50 in use)
* Japan
o AH-1S (licence-manufactured by Fuji Heavy Industries, 89 delivered)
* Jordan
o AH-1F (33 in use)
* Republic of Korea
o AH-1S (42 delivered)
o AH-1F (20 delivered)
* Pakistan
o AH-1F (18 in use)
* Taiwan (Republic of China)
o AH-1W (63 delivered)
* Thailand
o AH-1F (3 in use)
* Turkey
o AH-1W (9 in use)
o AH-1P/S (32 delivered)
* United States
o Marine Corps
+ AH-1W (approx. 269 delivered)
o Navy
+ AH-1W (7 in use)
Specifications
General Characteristics
* Role: attack helicopter
* Crew: two, pilot and copilot/gunner
* Length: 13.6 m (44 ft 7 in)
* Width: 1 m (3.3 ft)
* Height: 4.1m (13 ft 5 in)
* Empty weight
o AH-1S: 2,993 kg (6,598 lb)
o AH-1Z: 5,398 kg (11,900 lb)
* Maximum takeoff weight
o AH-1S: 4,535 kg (10,000 lb)
o AH-1Z: 8,392 kg (18,500 lb)
* Powerplant
o AH-1G: 1x Avco Lycoming T53-L-13 turboshaft, 1,800 shp (1,300 kW)
o AH-1Q, AH-1S: 1x Avco Lycoming T53-L-703 turboshaft
o AH-1J, AH-1T: 2x Pratt & Whitney Canada PT6T (T400) turboshaft
o AH-1T, AH-1W, AH-1Z: 2x General Electric T700-GE-401 turboshaft, 1,723 shp each
Performance
* Maximum speed
o AH-1S: 195 km/h (105 knots)
o AH-1Z: 411 km/h (222 knots)
* Combat range
o AH-1S: 507 km (315 miles)
* Service ceiling
o AH-1S: 3,720 m (12,200 ft)
* Rate of climb
o AH-1S: 494 m/min (1,620 ft/min)
Armament
* AH-1G
o M134 7.62-mm minigun and M129 40-mm grenade launcher mounted in an Emerson M28 nose turret. Twin M134s or twin M192s could also be fitted in the turret.
o 7.62-mm gun pods and 2.75-in rocket pods mounted on the stub wings
* AH-1Q
o Added capability for BGM-71 TOW anti-tank missiles
* AH-1E (AH-1S Step 2)
o M28 turret replaced by an M197 20-mm cannon mounted in the M97A1 Universal Turret
* AH-1W
o Added capability for laser-guided AGM-114 Hellfire anti-tank missiles, AIM-9 Sidewinder air-to-air missiles and AGM-122 Sidearm anti-radiation missiles
