UP CLOSE U.S. Air Force's 28th Maintenance Squadron members perform an isochronal inspection on a B-1B Lancer bomber on Ellsworth Air Force Base, S.D., Sept. 17, 2009. During this inspection, airmen look for and repair cracks, chafed wires, worn seals, leaks and other damage to the aircraft. SHARE: Download: Full Size (0.06 MB) Credit: VIRIN: 400828-Y-OXS61-079.jpg Photo Gallery