Tech. Sgt. Ronnie Graham, 403rd Maintenance Squadron jet engine craftsman, checks a WC-130J engine for an oil leak May 1, 2015. Most oil leaks can be troubleshot with the engine sitting static; however, in some cases the engines must be running for a maintainer to properly diagnose the source of the oil leak. (U.S. Air Force photo/Maj. Marnee A.C. Losurdo)