Staff Sgt. Matthew Stormer performs a preflight inspection on an F-35 Lightning II joint strike fighter before a training and testing mission June 20, 2013, at Eglin Air Force Base, Fla.The aircraft is still in the testing phase and will be used by the Air Force, Navy and Marine Corps, along with international partners such as the United Kingdom. Stormer is a dedicated crewchief assigned to the 33rd Maintenance Group.