Engineers design a lighter AC-130 ammunition rack Published Aug. 10, 2004 By Lanorris Askew Warner Robins Air Logistics Center Public Affairs ROBINS AIR FORCE BASE, Ga. (AFPN) -- The AC-130H gunship’s mighty arsenal has a new home that is lighter and more efficient for the low-flying hunter of the sky. And, its engineers and users said the modification is making a positive difference.A new ammunition rack is more than 1,000 pounds lighter than its predecessor -- a weight reduction that does not show on the outside, but makes a noticeable difference aerodynamically.Gene Etters, an equipment specialist with the special operations forces directorate here, said gunships were originally built for missions over Southeast Asia which lies at sea level, but, the aircraft now fly missions where the terrain is much higher.“With the heavy ammunition the aircraft carries, it wasn’t able to get very high,” he said. “The higher you go, the less vulnerable you are to a ground-based threat, and to get higher, we had to go into a weight-reduction effort.”Mike Hilton, an aerospace engineer here, said the ammo rack was the perfect solution.“We always have a challenge with the gunship and maintaining the correct center of gravity for safety-of-flight issues,” he said. “To manage our center of gravity, we try to push (weight) forward as much as we can. The more weight there is in the back of the airplane, the more negatively it (affects) the center of gravity. Since the ammo rack is stored in the back of the aircraft, it was the prime location for that weight reduction.” After looking at the composition and weight of the ammo rack, they looked at new designs. System engineers here received help from the designers at the Aeronautical Systems Center at Wright-Patterson Air Force Base, Ohio, for building the rack, but the people writing installation data for it and repairing it are here.The new racks were installed two years ago and are currently used in the entire fleet of gunships stationed at Hurlburt Field, Fla.The AC-130H is now more aerodynamically centered, and the new rack has a lot more storage room and easier access.“The ammunition rack holds the ammo securely during flight and makes it readily available for use by the crew,” Mr. Hilton said. “The gunners have to have a rack that these rounds are stored in so they can pull it off and put it in the gun. When they fire the shot, they take the shell out of the gun and put it back in the rack.”Three Airmen assigned to the 16th Special Operations Squadron at Hurlburt Field, gave their first-hand experiences with the new racks, but asked to have their names withheld for security reasons.A gunner said one big difference is that before the new rack, 24 rounds were kept in the front of the aircraft and 76 in the back. “We now have all of our rounds located in the back of the aircraft, which keeps the other guy from having to shuffle ammo,” he said. “That saves time and allows us to get more rounds on target.”Another gunner said the ease of accessibility as far as 105 mm rounds is the biggest plus for him. “The old drawers used to lock up, and you’d have to have two people open the door if the drawer collapsed on them, and that would slow you down a lot,” he said. “(The new racks) took them out of the drawer situation and put them in the basic sleeves which are locked in by a handle in the back. That also makes it easier to get the rounds out.”This may all sound simple, but, when Airmen are dealing with 105 mm shells -- each about 33 pounds and 3 feet long -- added distance and accessibility can be a very big deal.A pilot said they can carry a lot more fuel and ammo now. “We can take off a little bit lighter too because we don’t have to have extra fuel,” he said. “It’s always safer to have a little lighter airplane. If we were ever to have a problem, it’s easier to maintain control of the aircraft if it’s lighter. It makes it safer for the whole aircrew.”Mr. Hilton said the back rack was so successful that they are going to use the same technology on the front.