In late 1965, the first Armed/Armoured Chinook was officially rolled out and testing was begun. The Armed/Armoured Chinook used its payload capability to advantage by mounting an extensive array of armament, as well as armor to protect the crew and vital parts of the aircraft against heavy calibre ground fire.
Mounted on the nose was an M-5 40mm Automatic Grenade Launcher. This turret-mounted weapon was controlled by the copilot, who was able to cover an extensive area on either side of the flight path. Complementing this nose turret, pylons on each side of the aircraft carried fixed forward-firing weapons including a 22mm gun and either a 19-round 2.75 inch rocket pod, or a 7.62mm high-rate-of-fire Gatling machine-gun.
The flanks of the aircraft were protected by four gunners stationed two to either side of the cabin. Each of these gunners was provided with either a 7.62mm or 12.7mm calibre machine-gun on flexible mounts. Another gunner was stationed aft with the same type weapons mounted on the rear loading ramp. From this vantage point, the gunner could protect the aircraft from ground fire after the aircraft had passed, a capability not present in previous armed helicopters. This aircraft carried a ton of expendable munitions.
The Armed/Armoured Chinook was provided with a new type of steel armour plate which was built into the crew seats and protected their torsos. Other steel plates protected components of the aircraft. The rugged components of the Chinook and extensive dualization of systems, combined with over a ton of armour plate, assured a high degree of survivability for the aircraft.
P.Allen "The Helicopter", 1996