In contrast to the prototype, the AH-1G had a fixed skid landing gear and the tail rotor was moved to the right during production. The lower tail fin of the tail fin was also omitted. The all-round glazed and top rounded canopy with panoramic view made of unarmoured safety glass caused an unpleasant greenhouse effect.
Therefore the first delivered AH-1G were equipped with ventilation nozzles. In the tropical regions of South East Asia, however, these were inadequate. For this reason, the Vietnamese workshops equipped the helicopters with air conditioning systems called “environmental control units” (ECU), which were later installed during series production. The “greenhouse glazing” represented the helicopter’s highest infrared signature, and even the hot engine exhaust gases did not attract infrared-guided weapons as much
on. In addition, the tail rotor of the late AH-1G was moved from the left to the right side compared to the UH-1C for stability reasons, otherwise almost the entire tail section was taken over by the UH-1C “Huey”. The early version had two landing lights in the plexiglass nose, the late version had a landing light below the nose.

The retractable reflex sight M73 served as aiming aid for all weapons. For the chin turret, the computer system compensates the helicopter’s own movements, wind influences and target movements. The AH-1G was only lightly armoured. The armoured shield in front of the cockpit protected against fire with weapons up to 7.62 mm calibre; the hydraulic and fuel guidance systems were also protected against bullets and splinters. Since there was a great need for attack helicopters in Vietnam for the reasons mentioned above and the gradual expansion of the war, and since the competing Lockheed AH-56 “Cheyenne” programme was discontinued due to uncontrollable conceptual deficiencies, the Cobra, initially intended only as a temporary solution, quickly proved convincing and soon proved to be indispensable.

As early as August 1967 the first HueyCobras reached the US forces in support of the South Vietnamese army. During the Vietnam War the United States Army had to write off 157 HueyCobras by anti-aircraft guns (FlaK), four by anti-aircraft missiles (FlaRak) and twelve by attacks on airfields as total losses due to enemy action and 109 by accidents. The USMC lost ten Cobras in the same period. However, most of them were only slightly damaged, then repaired and put back into service. The main task of the HueyCobras at that time was to be used as airmobile artillery, armed escort and armed reconnaissance. It soon became apparent that the M64 turret, even in combination with two M18 containers, did not provide enough firepower. The problem with the powerful unguided FFAR missiles was that during demonstrations the highly professional army instructors could fire them with pinpoint accuracy, but the untrained army pilots could not achieve this precision. At night, in combination with UH-1-“Hueys”, which were equipped with headlight bundles on the sides, targets could still be engaged. As a rule, however, the HueyCobras remained on the ground in bad weather and at night.

After AH-1Gs were shot down by North Vietnamese with 9K32 “Strela-2” anti-aircraft guided missiles in 1972 during the spring offensive, measures had to be taken to improve the infrared signature. A so-called “sugar scoop” (or “sugar bowl”) was attached to the engine outlet. With its toilet bowl-like shape and a heat-insulating coating of asbestos and metal layers, it diverted the hot exhaust gases into the main rotor, where they were mixed with ambient air and dispersed. The slightly tinted cockpit windows were replaced by clear ones in later versions.

The further development of the G version was the AH-1Q “HueyCobra”.

With the delivery of the new Hughes AH-64A “Apache”, the United States Army replaced most of its AH-1F “Cobra” from the late 1980s. Only one air cavalry battalion of the Army still uses AH-1F Cobras; the rest are in reserve with the National Guard. From the end of 2004, there will only be TAH-1S “surrogates” in the Army for night flight training of Apache pilots. However, the United States Marine Corps continues to use the “SuperCobra” variant to this day, as it is ideally suited to the needs of this special force and the cramped conditions on their amphibious vessels (small, light, small footprint, seaworthy and high firepower in relation to size). As the Marine Corps did not want to do without the agile Cobras, their AH-1J/T stock was upgraded to the level of the improved model AH-1W “SuperCobra” from existing cells. The AH-1W “SuperCobra” is more agile than its predecessor AH-1T due to its two increased performance T700 turbines and can finally carry full armament over longer distances into the combat zone. It also has newer avionics and the ability to carry AIM-9 Sidewinder air-to-air missiles. The “SuperCobra” thus poses a threat to enemy helicopters and combat aircraft. The USMC usually omits the AIM-9 Sidewinder, as it would otherwise occupy the two main suspension points. The existing armour only includes the two pilot seats and the rotor blades, which can withstand anti-aircraft ammunition up to 23 mm calibre. The remaining part of the helicopter is unarmoured, which greatly reduces its survivability in the event of enemy fire. During Operation Urgent Fury, for example, two AH-1Ts crashed after being fired upon right at the start of the attack. The wire-guided TOW missiles were supplemented by the modern laser-guided AGM-114 “Hellfire”. However, since the expensive Hellfire can only be used effectively against armoured targets, the cheaper TOW missiles are more efficient for operations in Afghanistan and Iraq.

Despite a very short development time, the remarkably successful AH-1 model was still far from being exhausted: the latest model AH-1Z “Viper” now features the latest computer and target acquisition technology and a four-bladed bearingless main rotor, with which flight performance has been further improved. However, the AH-1Z no longer has the capability of using the TOW anti-tank guided missiles. During the further development of the AH-1Z, Bell’s H-1 programme
At the same time, the UH-1N was modernised into the UH-1Y “Venom”. This should enable a large part of the components such as engine, gearbox, avionics, rotor head etc. to be used for both helicopters. Bell estimates that the 84% interchangeability of parts will reduce operating costs by approximately 3 billion US dollars over a 30-year service life.