A C-5 Galaxy engine cover, on display in the 22nd Airlift Squadron building at Travis Air Force Base, Calif., March 28, 2012, is signed by the 11 crewmembers on board Jan. 8, 2004, when the aircraft was hit with a surface-to-air missile strike. The engine cowling, or cover, has been on display since 2004 and serves as a reminder of the training, preparedness and resolve the squadron faced during that mission. (U.S. Air Force photo/Tyler Grimes)