Bell AH-1W SuperCobra

The Bell AH-1 SuperCobra is a twin-engine attack helicopter based on the US Army's AH-1 Cobra. The twin Cobra family includes the AH-1J SeaCobra, the AH-1T Improved SeaCobra, and the AH-1W SuperCobra. The AH-1W is the backbone of the United States Marine Corps's attack helicopter fleet, but will be replaced in service by the AH-1Z Viper upgrade in the next decade.

Development

The AH-1 Cobra was developed in the mid-1960s as an interim gunship for the U.S. Army for use in Vietnam. The Cobra shared the proven transmission, rotor system, and the T53 turboshaft engine of the UH-1 "Huey".[2]

By June 1967, the first AH-1G HueyCobras had been delivered. Bell built 1,116 AH-1Gs for the U.S. Army between 1967 and 1973, and the Cobras chalked up over a million operational hours in Vietnam.[2]

The U.S. Marine Corps was very interested in the AH-1G Cobra, but preferred a twin-engined version for improved safety in over-water operations, and also wanted a more potent turret-mounted weapon. At first, the Department of Defense had balked at providing the Marines with a twin-engined version of the Cobra, in the belief that commonality with Army AH-1Gs outweighed the advantages of a different engine fit. However, the Marines won out and awarded Bell a contract for 49 twin-engined AH-1J SeaCobras in May 1968. As an interim measure, the U.S. Army passed on 38 AH-1Gs to the Marines in 1969.[3] The AH-1J also received a more powerful gun turret. It featured a three barrel 20 mm XM197 cannon that was based on the six barrel M61 Vulcan cannon.[4]
An AH-1T Sea Cobra prepares to land aboard the amphibious assault ship USS Iwo Jima.
An AH-1T Sea Cobra prepares to land aboard the amphibious assault ship USS Iwo Jima.

The Marine Corps requested greater load carrying capability in high temperatures for the Cobra in the 1970s. Bell used systems from the Model 309 to develop the AH-1T. This version had a lengthened tailboom and fuselage with an upgraded transmission and engines from the 309. Bell designed the AH-1T to be more reliable and easier to maintain in the field. The version was given full TOW capability with targeting system and other sensors. An advanced version, known as the AH-1T+ with more powerful T700-GE-700 engines and advanced avionics was proposed to Iran in the late 1970s, but the overthrow of the Shah of Iran resulted in the sale being canceled.[4]

In the early 1980s, the U.S. Marine Corps sought a new navalized helicopter, but was denied funding to buy the AH-64 Apache by Congress in 1981. The Marines in turn pursued a more powerful version of the AH-1T. Other changes included modified fire control systems to carry and fire AIM-9 Sidewinder and AGM-114 Hellfire missiles. The new version was funded by Congress and received the AH-1W designation.[4] At least 266 were delivered.

The AH-1T+ demonstrator and AH-1W prototype was later tested with a new experimental composite four blade main rotor system. The new system offered better performance, reduced noise and improved battle damage tolerance. Lacking a USMC contract, Bell developed this new design into the AH-1Z with its own funds. By 1996, the Marines were again not allowed to order the AH-64.[4] Developing a marine version of the Apache would have been expensive and it was likely that the Marine Corps would be its only customer.[2] They instead signed a contract for upgrading 180 AH-1Ws into AH-1Zs.[4]

The AH-1Z Viper features several design changes. The AH-1Z's two redesigned wing stubs are longer with each adding a wing-tip station for a missile such as the AIM-9 Sidewinder. Each wing has two other stations for 70 mm (2.75 in) Hydra rocket pods, or AGM-114 Hellfire quad missile launcher. The Longbow radar can be mounted on a wing tip station.[2]

[edit] Operational history
U.S. Marines AH-1W SuperCobra refueling during Operation Iraqi Freedom.
U.S. Marines AH-1W SuperCobra refueling during Operation Iraqi Freedom.

During the Gulf War in 1990-91, the Cobras and SeaCobras deployed in a support role. A total of 78 Marine SeaCobras flew 1,273 sorties[5] with no combat losses. Three AH-1s were lost in accidents during fighting and afterwards. Marine AH-1Ws destroyed 97 tanks, 104 armored personal carriers and vehicles, and two anti-aircraft artillery sites during the 100-hour ground campaign.[4]

Iranian AH-1J SeaCobras participated in air combat with Iraqi Mi-24s on several separate occasions during the Iran–Iraq War. The results of these engagements are disputed. One document cited that "Iranian AH-1Js engaged Iraqi MI-8 Hip and MI-24 Hind helicopters.[6] Unclassified sources report that the Iranian AH-1 pilots achieved a 10:1 kill ratio over the Iraqi helicopter pilots during these engagements (1:5). Additionally, Iranian AH-1 and Iraqi fixed wing aircraft engagements also occurred. Others claim that in the entire eight-year conflict, ten Iranian AH-1Js were lost in combat, compared to six Iraqi Mi-24. The skirmishes are described as fairly evenly matched in another source.[7] Iranian AH-1Js are still operating today and have undergone indigenous upgrade programs. In 1988, two Soviet MiG-23s shot down a pair of Iranian AH-1Js[8] that had strayed into western Afghan airspace.

AH-1 Cobras continue to operate with the U.S. Marine Corps. USMC Cobras were also used in operations throughout the 1990s.[4] USMC Cobras have also served in Operation Enduring Freedom in Afghanistan and in Operation Iraqi Freedom in the ongoing conflict in Iraq. While new replacement aircraft were considered as an alternative to major upgrades of the AH-1 fleet, Marine Corps studies showed that an upgrade was the most affordable, most supportable and most effective solution for the Marine Corps light attack helicopter mission.[9]

Variants

Single-engine
Twin-engine

AH-1J SeaCobra
Original twin engine version.
AH-1J International
Export version of the AH-1J SeaCobra.
AH-1T Improved SeaCobra
Improved version with extended tailboom and fuselage and an upgraded transmission and engines.
AH-1W SuperCobra
("Whiskey Cobra"), day/night version with more powerful engines and advanced weapons capability.
AH-1Z Viper
("Zulu Cobra"), in conjunction with the UH-1Y Venom upgrade. Version includes an upgraded 4 blade main rotor and adds the Night Targeting System (NTS).
Model 309 King Cobra
Experimental version powered by two engines.
Cobra Venom
Proposed version for the United Kingdom.
AH-1RO Dracula
Proposed version for Romania.
AH-1Z King Cobra
AH-1Z offered under Turkey's ATAK program; selected for production in 2000, but later canceled when Bell and Turkey could not reach an agreement on production.[10]
Panha 2091
unlicensed Iranian upgrade of the AH-1J International.

Operators

See also: AH-1 Cobra for operators of AH-1G, AH-1Q through AH-1S/P/E/F and other single-engine variants.

Iran

* Islamic Republic of Iran Army received 202 AH-1J Internationals. Iran operates 30 AH-1Js as of 2008.[11] An unknown number of the Panha 2091, an unlicensed, locally-made upgrade of AH-1J serve with the Army and Revolutionary Guards.

Republic of China (Taiwan)

* Republic of China Army received 63 AH-1Ws and operates 59 AH-1Ws as of 2008.[11]

Turkey

* Turkish Army operates 7 AH-1W Super Cobras as of 2008.[11]

United States

* United States Marine Corps has approximately 167 AH-1Ws as of 2008.[11]
o HMLA-167, MCAS New River
o HMLA-169, MCAS Camp Pendleton
o HMLA-267, MCAS Camp Pendleton
o HMLA-269, MCAS New River
o HMLA-367, MCAS Camp Pendleton
o HMLA-369, MCAS Camp Pendleton
o HMLA-773, NAS Atlanta
o HMLA-775, MCAS Camp Pendleton
o HMT-303, MCAS Camp Pendleton
o Due to a re-organization within Marine aviation, the Marine Corps will be adding three active duty light/attack helicopter squadrons in the next few years. In 2008 the will add HMLA-467. 2009 will see the addition of HMLA-469 and HMLA-567.[12]
* United States Navy used 7 AH-1Ws for test and evaluation purposes on behalf of the USMC.

Specifications

AH-1J SeaCobra

Data from Aviation Enthusiast Corner[13]

General characteristics

* Crew: 2: pilot, CPG (co-pilot/gunner)
* Length: 44 ft 3 in (13.5 m)
* Rotor diameter: 43 ft 11 in (13.4 m)
* Height: 13 ft 5 in (4.1 m)
* Empty weight: 6,595 lb (2,998 kg)
* Max takeoff weight: 9,979 lb (4,525 kg)
* Powerplant: 1× Pratt & Whitney Canada T400-CP-400 (PT6T-3 Turbo Twin-Pac) turboshaft, 1,800 shp (1,342 kW)
* Total engine output: 1,530 shp (1,125 kW) limited by helicopter drivetrain[4]
* Rotor systems: 2 blades on main rotor, 2 blades on tail rotor

Performance

* Maximum speed: 190 knots (218 mph, 352 km/h)
* Range: 308 nmi (355 mi, 571 km)
* Service ceiling 11,398 ft (3,475 m)

Armament

* M197 3-barreled 20 mm "Gatling-style" cannon in the M97 turret (750 rounds ammo capacity)
* 2.75 in (70 mm) Mk 40 or Hydra 70 rockets - 14 rockets mounted in a variety of launchers
* 5 in (127 mm) Zuni rockets - 8 rockets in two 4-round LAU-10D/A launchers
* AIM-9 Sidewinder Anti-Aircraft Missiles - 1 mounted on each hardpoint

Data from The International Directory of Military Aircraft, 2002-2003[14]

General characteristics

* Crew: 2: pilot, CPG (co-pilot/gunner)
* Length: 44 ft 7 in (13.6 m)
* Rotor diameter: 48 ft (14.6 m)
* Height: 13 ft 5 in (4.1 m)
* Disc area: 530.83 ft² (168.1 m²
* Empty weight: 10,920 lb (4,953 kg)
* Max takeoff weight: 14,750 lb (6,690 kg)
* Powerplant: 2× General Electric T700 turboshaft, 1,680 shp (1,300 kW) each
* Rotor systems: 2 blades on main rotor, 2 blades on tail rotor

Performance

* Maximum speed: 190 knots (218 mph, 352 km/h)
* Range: 317 nmi (365 mi, 587 km)
* Service ceiling 12,200 ft (3,720 m)
* Rate of climb: 1,620 ft/min (8.2 m/s)

Armament

* M197 3-barreled 20 mm "Gatling-style" cannon in the A/A49E-7 turret (750 rounds ammo capacity)
* 2.75 in (70 mm) Hydra 70 rockets - Mounted in LAU-68C/A (7 shot) or LAU-61D/A (19 shot) launchers
* 5 in (127 mm) Zuni rockets - 8 rockets in two 4-round LAU-10D/A launchers
* TOW Missiles - Up to 8 missiles mounted in two-missile launchers on each hardpoint
* AGM-114 Hellfire Missiles - Up to 8 missiles mounted in two 4-round M272 missile launchers, one on each outboard hardpoint
* AIM-9 Sidewinder Anti-Aircraft Missiles - 1 mounted on each outboard hardpoint (total of 2)