U.S. Air Force airmen conduct a phase post engine run operational check. U.S. Air Force airmen of the 332nd Expeditionary Maintenance Squadron conduct a phase post engine run operational check on a F-16 Fighting Falcon at Balad Air Base, Iraq, on March 22, 2007. Air Force maintenance personnel ensure that all ground and functional checks are accomplished after every 400 flying hours to make sure every aircraft is mission ready. SHARE: Download: Full Size (0.03 MB) Credit: VIRIN: 088062-G-BJW99-672.jpg Photo Gallery