Mounted on the nose was an M-5 40mm Automatic Grenade Launcher (see photo on right), fed by an ammo chute that ran from it's ammo box, mounted in the forward/center cabin area (see photo on left), underneath the cockpit radio consol, and out the nose. 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, stub-wing pylons on each side of the aircraft carried fixed forward firing weapons, including two 20mm cannons (ammo boxes located bilaterally within the aircraft center cabin area, and fed via chutes that ran through the stub-wings: see photo on left), and either a 19-round 2.75 inch rocket pod, or a 7.62mm high-rate-of-fire Gatling machine gun. (Ed. "mini-gun") However the 2.75 inch rocket pod became standard equipment.
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 an M-60 or .50 caliber machine gun on flexible mounts. Generally, the .50 was mounted and the M-60 was inside, used as a backup weapon. 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/Armored Chinook (The duel designation was dropped to a single 'A' for ATTACK, in Vietnam; ACH-47A) was provided with a new type of steel armor 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 armor plate, assured a high degree of survivability for the aircraft.