It used the same engine, transmission and rotor system as the Bell UH-1 Iroquois, which had already proven itself to be a capable platform during the conflict, but paired it with a redesigned narrow fuselage among other features.

The original AH-1, being a dedicated attack helicopter, came equipped with stub wings for various weapons, a chin-mounted gun turret, and an armored tandem cockpit, from which it was operated by a pilot and gunner.

Its design was shaped to fulfill a need for a dedicated armed escort for transport helicopters, giving the latter greater survivability in contested environments.

Furthermore, surplus AH-1 helicopters have been reused for other purposes, including civilian ones; numerous examples have been converted to perform aerial firefighting operations.

[4] While some officials within the Pentagon, particularly those within the US Army, had recognized the potential value of purpose-built armed rotary aircraft as early as 1962 and were keen to see such a vehicle developed promptly, the issue was complicated in part due to inter-service politics.

Meanwhile, some Army officials were concerned that the USAF did not take the close air support (CAS) mission as seriously as it ought to, and that response times of 30 minutes or more for fixed-wing aircraft would be unacceptable.

The Iroquois Warrior was planned to be a purpose-built attack aircraft based on 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 SS.10 anti-tank missiles.

The Sioux Scout had all the key features of a modern attack helicopter: a tandem cockpit, stub wings for weapons, and a chin-mounted gun turret.

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

[6] Despite the Army's preference for the AAFSS program—for which Bell Helicopter was not selected to compete—the company persisted with their own idea of a smaller and lighter gunship, noting that Lockheed had little experience in developing rotorcraft and correctly predicted that it would encounter considerable difficulties.

[6][4] Bell employee Mike Folse played a key role in developing this new gunship, which he intentionally based around the existing UH-1 on the rationale that, while the Army could not purchase a completely original helicopter without a formal design competition, the service was able to procure a modification of an aircraft that was already in its inventory without invoking such hurdles.

[6] It largely resembled the "Iroquois Warrior" mockup,[7] particularly in its cockpit and tail boom; in broad visual terms, there was relatively little shared between the proposed design and the UH-1.

[4] On 3 September 1965, Bell rolled out its Model 209 prototype, and four days later it made its maiden flight, only eight months after the project's go-ahead and slightly under budget.

[12] Within its first decade of service, the US Army had put the original Cobra model through various exercises and operations, which highlighted both the attack helicopter's promise and areas in which it could be improved.

During March 1978, the US Army opted to procure a batch of 100 new-build Cobras that featured a new T-shaped instrument panel, improved composite rotor blades, revised transmission and gearboxes, the M128 helmet-mounted sight, and the M28A3 armament system.

These dynamic changes were combined with the adoption of heavier armaments, which provided the USMC with an effective anti-armor capacity, unlike the preceding model.

[20] The Bell AH-1 Cobra is a dedicated attack helicopter, built to provide close air support and to escort friendly troop transports.

[4] Aviation author Stanley McGowen observed that its appearance differed radically from any prior rotorcraft designed by Bell, possessing a relatively narrow fuselage and a then-unusual cockpit arrangement.

[4] The slim profile of the helicopter allegedly provided defensive benefits by making it harder for opponents to accurately hit it with small arms fire, although man-portable air-defense system (MANPADS) did prove to be effective against the Cobra.

It was unusual for Cobras to operate alone; instead, two or more would be dispatched and teamwork encouraged, leading to hunter-killer tactics being used to flush out and eliminate ground targets.

[22] The first six AH-1s arrived at Bien Hoa Air Base, South Vietnam on 30 August 1967 for combat testing by the U.S. Army Cobra New Equipment Training Team.

Typically, the AH-1 provided fire support for ground forces and escorted transport helicopters, in addition to other roles, including aerial rocket artillery (ARA) battalions in the two Airmobile divisions.

[30][31] During Operation Urgent Fury, the invasion of Grenada in 1983, several Marine AH-1T SeaCobras and Army AH-1S Cobras were deployed to fly close air support and helicopter escort missions.

[36] The service, which had long sought a more capable successor to the Cobra, had procured a large fleet of AH-64 Apaches since receiving the first example of the type during early 1984.

[41] Largely due to a US embargo that prevented the purchase of further Cobras, Israel procured alternative platforms instead, including around 20 McDonnell Douglas MD 500 Defenders in late 1979.

[45] At the time of the Apache's procurement, there was considerable political controversy over the IAF's decision to overlook upgrades to its existing Cobra fleet in favour of acquiring an entirely separate model of attack helicopter.

The Cobras were also more expensive to maintain than UAVs and their use exposed pilots to attacks from man-portable air-defense systems operated by guerrilla groups.

[48][49] In late 2014, Israel transferred 16 of the recently-withdrawn Cobras to the Royal Jordanian Air Force to bolster the numbers of their existing fleet.

[6] These have been designated Bell 209 and are being converted into Firewatch Cobras with infrared and low light sensors and systems for real time fire monitoring.