File:330-ps-8882-usn-710122 15816738948 o.jpg

English: 330-PS-8882 (USN 710122): Mark 11, 20mm Aircraft Gun, in the Mark 1 POD, attached to the bomb rack of a Douglas A4D-2 aircraft, April 14, 1958. Master Caption: The U.S. Navy today unveiled a new pod-mounted weapon, a 20mm aircraft gun capable of firing 4,000 rounds per minute. This gun, called the Mark 11, was shown to Naval Aviators and representatives of the press at the Third Annual Naval Air Weapons Meet, held at the U.S. Naval Auxiliary Air Station, El Centro, California. This new weapon, which will offer a significant contribution to Naval Air Attack Capability, is carried and fired in an external pod which is fitted to the bomb rack of carrier-based aircraft. Its primary application is in air-to-ground attack, where its controlled variable rate of fire makes it extremely effective. Ease of rearming, replacement of the gun, and maintenance are notable features which add to the practicability of the gun. Rear Admiral Paul D. Stroop, Chief of the Bureau of Ordnance, indicated that with the Mark 11 gun and POD meeting the firepower requirements of future attack aircraft, there will be a gain in aircraft structural simplicity, since there would be no need for internal fixed guns. Mr. Frank Markquaret, a Naval Ordnance Engineer in the Bureau of Ordnance, conceived the Mark 11 gun and POD. It was developed for the U.S. Navy by Flier Industrialist, Howard Hughes. The Mark 11 is presently undergoing evaluation at the Naval Aviation Ordnance Test Station, Chincoteague, Virginia, and is expected to be operational in 1959. Photograph released April 14, 1958. (12/09/2014).