The Bell AH-1 Cobra was the backbone of the US army's attack helicopter fleet from the late 1960 to the mid 1980's when they were replaced by the AH-64 Apache. The Cobra continue to fly in various guises with several other users including the US Marine Corps, with the upgraded, twin-engined AH-1Z SuperCobra poised to enter operational service after 2011.

The AH-1s development closely ties in with that of the ubiquitous UH-1 Iroquois, more commonly know as the Huey. During the Vietnam war, it soon became clear that the unarmed troop carrying Huey's were vulnerable to ground fire, particularly during landing. To combat this, a small number or UH-1s were armed with machine guns and rocket mounts and used to escort the troop carriers.

Bell, having investigated helicopter gunships since the 1950s were awarded a proof of concept contract by the US Army in 1962 for its armed 207 Sioux Scout. The 207 however never took off as it was deemed too small, underpowered and fragile to be of practical use.

Consequently left out of the Army's Advanced Aerial Fire Support System (AAFSS) competition, Bell continued with its idea of a small light gunship and invested $1m in its 209 prototype, mixing the T-53 turboshaft engine, transmission and rotor systems from the UH-1, with a new design, based on its 207.

With the AAFSS competition encountering technical and political difficulties, the US Army put out tenders for an interim gunship. In September 1965 Bell rolled out its 209 and in April 1966, it won an evaluation against other competing helicopters with the Army placing orders for 110 rotorcraft. By Mid 1967, the first Cobras had entered service and by 1973 had chalked up over 1 million operational hours.

SuperCobra

The AH-1W SuperCobra is a twin-engined variant of the Bell Ah-1 Cobra. Designed to fill the needs of the US Marine Corps who wanted a twin-engined version of the Cobra for improved safety in over-water conditions as well as a more powerful arsenal of weaponry. Bell were awarded a contract to build 49 AH-1Js in 1969, with the first completed models entering service in 1971.

To date there are over 20 variants of the Cobra/SuperCobra operated by a dozen nations.

For more information on the AH-1 visit the manufacturer's website