EXHAUST INSPECTION U.S. Air Force Staff Sgt. Greg Penrod performs an exhaust inspection on an F-16 Fighting Falcon during Red Flag-Alaska 12-2 on Eielson Air Force Base, Alaska, June 14, 2012. Penrod, a crew chief, is assigned to the 20th Aircraft Maintenance Squadron, Shaw Air Force Base, S.C. SHARE: Download: Full Size (0.07 MB) Credit: VIRIN: 128072-Z-KFO29-070.jpg Photo Gallery