AH-1 Cobra

The Bell AH-1 Cobra is a single-engine, two-seat attack helicopter developed by Bell Helicopter in the United States as an interim gunship for the Vietnam War. Also called the HueyCobra, it mated the engine, transmission and rotor system of the UH-1 Iroquois to a narrow fuselage with an armoured tandem cockpit, stub wings and a chin turret. The Model 209 prototype first flew on 7 September 1965 and the AH-1G entered US Army service in June 1967. It was the core of the Army's attack helicopter force until the AH-64 Apache displaced it in the 1990s; the twin-engine AH-1J and AH-1T built for the US Marine Corps led to the AH-1W SuperCobra and AH-1Z Viper, covered on their own pages.

Development

In June 1962 Bell showed the US Army its D-255 "Iroquois Warrior" mockup, a gunship on UH-1B components with a slender airframe, tandem cockpit, nose turret and stub wings for rockets or SS.10 anti-tank missiles. A proof-of-concept contract in December 1962 produced the Model 207 Sioux Scout, a modified Model 47 flown in July 1963; the Army judged it undersized and underpowered and launched the AAFSS competition for a heavy gunship capable of at least 320 km/h (200 mph), which produced the Lockheed AH-56 Cheyenne, cancelled in 1972.

Excluded from AAFSS, Bell committed $1 million in January 1965 to a lighter gunship built as a modification of an aircraft already in Army inventory, which could be bought without a formal competition. The Model 209 combined the UH-1C's "540" rotor system, with a Stability Control Augmentation System added, and the UH-1's transmission and T53 turboshaft with the Sioux Scout layout. Rolled out on 3 September 1965, it flew four days later. The Army evaluated it against armed versions of the Boeing-Vertol ACH-47A, Kaman HH-2C, Piasecki 16H Pathfinder and Sikorsky S-61, selected Bell in April 1966 and ordered 110 aircraft, raised to 500 by year's end. Production aircraft had fixed skids and a plexiglass canopy in place of heavy armoured glass. Bell built 1,116 AH-1Gs for the Army between 1967 and 1973.

The Improved Cobra Armament Program trialled eight TOW-armed AH-1s in October 1973 and led to 101 AH-1Gs becoming TOW-capable AH-1Qs. In March 1978 the Army ordered 100 new-build Cobras with composite rotor blades, the M128 helmet-mounted sight and an uprated T53; this AH-1S family was upgraded in three steps ending with the AH-1F. The Marine Corps ordered the twin-engine AH-1J in 1968 and in the early 1970s the AH-1T, which took its longer fuselage, tailboom and dynamic components from the experimental Bell 309 KingCobra.

Design

The AH-1G fuselage is 13.5 m (44 ft 5 in) long and 3.15 m (10 ft 4 in) wide across the stub wings. The gunner sits in front and the pilot-commander behind and above in a stepped tandem cockpit under a fighter-style canopy; both positions have flight controls and tempered-steel armoured seats. Empty weight is 2,635 kg (5,810 lb), maximum take-off weight 4,309 kg (9,500 lb), and the two-blade main rotor spans 13.4 m (44 ft). The Lycoming T53-L-13 turboshaft, rated at 1,400 shp (1,040 kW) but limited to 1,100 shp (820 kW) by the transmission, gives a maximum speed of 276 km/h (171 mph), a never-exceed speed of 350 km/h (220 mph), a range of 570 km (360 mi) and a service ceiling of 3,475 m (11,400 ft). The AH-1S and later models use the 1,800 shp (1,340 kW) T53-L-703.

Against armed UH-1s the Cobra carried twice the ammunition, reached the battle area in half the time and loitered three times as long. The AH-1F added a head-up display, laser rangefinder, the M143 Air Data Subsystem, an infrared jammer above the exhaust, a radar jammer and an infrared-suppressing exhaust. Crews avoided hovering under fire, flew low in pairs or more, and teamed with OH-6A Cayuse or OH-58 Kiowa scouts in hunter-killer teams.

Armament

The AH-1G's M28 chin turret carries two 7.62 mm Miniguns, two M129 40 mm grenade launchers, or one of each. The stub-wing hardpoints take 2.75 in (70 mm) rockets in seven-tube M158 or 19-tube M200 launchers, an M18 7.62 mm Minigun pod, or the XM35 subsystem with an XM195 20 mm cannon. The AH-1Q introduced the M65 TOW/Cobra subsystem with the M65 Telescopic Sight Unit and M73 reflex sight, retained by every later version; the AH-1E's Enhanced Cobra Armament System brought the M97A1 subsystem with a three-barrel M197 20 mm cannon and the M147 Rocket Management Subsystem. Israel fired Orev missiles from 1979 and added the Spike missile in the 2000s; Pakistan's AH-1Fs received the C-NITE thermal imaging package.

Operational History

The first six AH-1Gs reached Bien Hoa Air Base on 30 August 1967 for combat testing, and the 334th Assault Helicopter Company was declared operational on 6 October 1967. Cobras gave fire support, escorted transports and flew aerial rocket artillery. The fleet peaked at 1,081 aircraft and logged more than a million flight hours in Vietnam; in Operation Lam Son 719 in Laos in 1971, 26 AH-1Gs were destroyed and 158 damaged, and about 300 AH-1Gs were lost in Vietnam to combat and accidents, a third of them in non-combat incidents. Two Marine AH-1Ts were shot down in Grenada in October 1983, and Army Cobras fought alongside the AH-64 for the first time in Panama in 1989. In the 1990–91 Gulf War the Army deployed 140 Cobras and the Marines 91 AH-1Ws; three AH-1s were lost in accidents. The Army retired the type from active units in March 1999 and from the reserves in September 2001; the US Forest Service acquired 25 ex-Army AH-1Fs in 2003 for conversion to Firewatch Cobras, the last of which were retired in October 2021.

Israel bought six AH-1Gs, formed its First Attack Helicopter Squadron on 1 December 1977 and named the type Tzefa; in the 1982 Lebanon War the fleet was reportedly responsible for destroying dozens of Syrian vehicles. Twenty-four new Cobras followed in 1983–85 and 14 surplus AH-1Fs in August 1996; Israel retired its last 33 in late 2013 and passed 16 to Jordan in late 2014. Fuji Heavy Industries built 89 AH-1S for the Japan Ground Self-Defense Force between 1984 and 2000; in December 2022 Japan decided to replace its 47 remaining AH-1S with unmanned aircraft. Jordan received 24 AH-1Fs in the late 1980s and nine more in 2001, and transferred 16 to Pakistan in 2010. Pakistan's first 20 arrived in 1985–86 and its fleet reportedly stood at 35 AH-1Fs by 2013. Turkey acquired ten AH-1Ws and 32 ex-Army Cobras and flew them in the 2010s against Kurdish insurgents along its Syrian and Iraqi borders, reportedly losing two to enemy fire. The Philippines received two ex-Jordanian AH-1S on 26 November 2019 and retired them on 28 December 2024. Bahrain, Kenya and South Korea also operate the type.

Variants

• AH-1G HueyCobra: Initial 1966 production gunship for the US Army with a Lycoming T53-L-13 turboshaft rated at 1,400 shp (1,040 kW) and the M28 chin turret.
• AH-1Q: AH-1G converted with the M65 TOW missile subsystem and Telescopic Sight Unit, the first production TOW-capable Cobra.
• AH-1S / AH-1P: AH-1Q re-engined with the 1,800 shp (1,340 kW) T53-L-703, followed by 100 new-build AH-1P (Step 1) with composite rotors and flat-plate canopy.
• AH-1E: Ninety-eight Step 2 aircraft with the Enhanced Cobra Armament System and three-barrel M197 20 mm cannon.
• AH-1F: Step 3 standard, 143 new-build and 387 converted AH-1Gs, with head-up display, laser rangefinder, infrared jammer and suppressed exhaust.
• AH-1J SeaCobra: Twin-engine version ordered by the US Marine Corps in 1968, the start of the twin-engine Cobra line.
• AH-1T: Marine Corps development of the early 1970s with the longer fuselage, tailboom and dynamic components of the Bell 309 KingCobra.