Firefighters from the 633rd Civil Engineer Squadron extinguish a simulated aircraft fire during an exercise at Langley Air Force Base, Va., July 25, 2014. Langley Air Force Base, NASA-Langley Research Center and City of Hampton, Va., emergency services were tested on their ability to effectively respond to an F-22 Raptor crash. (U.S. Air Force photo by Senior Airman Aubrey White/Released)