Senior Airman Nicholas Tester performs an isochronal inspection on a B-1B Lancer. U.S. Air Force Senior Airman Nicholas Tester, an aerospace maintenance journeyman with the 28th Aircraft Maintenance Squadron, performs an isochronal inspection on a B-1B Lancer bomber's General Electric F101 turbofan engine at Ellsworth Air Force Base, S.D., on June 16, 2009. SHARE: Download: Full Size (0.05 MB) Credit: VIRIN: 988155-U-NHX63-847.jpg Photo Gallery