Tech. Sgt. David Sparkman magnetizes a boom strut bolt on a KC-135 Stratotanker April 12, 2011, during a magnetic particle inspection. Sergeant Sparkman is from the Pennsylvania Air National Guard’s 171st Air Refueling Wing and is deployed with the 313th Air Expeditionary Wing at an air base in Western Europe supporting Operation Unified Protector, a NATO-led mission in Libya, to protect civilians and civilian-populated areas under threat of attack. The 313th AEW provides aerial refueling to U.S. and coalition aircraft using KC-135 Stratotankers and KC-10 Extenders. (U.S. Air Force photo/Senior Airman Ethan Morgan)