MACHINE GUN MASTERY U.S. Air Force Master Sgt. Eric Marshall instructs Afghan National Air Core airmen on how to fire a PKM general purpose machine gun from an Mi-17 Hip helicopter at the Kabul Military Training Center in Kabul, Afghanistan, May 12, 2008. Marshall is assigned to the Combined Air Power Transition Force and is deployed from the 18th Air Maintenance Squadron, Kadena Air Force Base, Japan. SHARE: Download: Full Size (0.08 MB) Credit: VIRIN: 919402-F-KMT31-040.jpg Photo Gallery