Ready to burn
Airman Joshua Martinez, 4th Equipment Maintenance Squadron non-destructive inspector, samples oil from an F-15E Strike Eagle for wear metals on Seymour Johnson Air Force Base, N.C., Oct. 16, 2009. If a part is cracked in the engine, particles of metal can break off in the oil and causing parts to malfunction. (U.S. Air Force photo/Senior Airman Ciara Wymbs)