A U.S. Air Force F-16 pilot adjusts his oxygen mask as he prepares to take off from Aviano. A U.S. Air Force F-16 Fighting Falcon pilot from the 510th Fighter Squadron adjusts his oxygen mask as he prepares to take off from Aviano Air Base, Italy, on a mission in support of NATO Operation Allied Force on April 21, 1999. Operation Allied Force is the air operation against targets in the Federal Republic of Yugoslavia. SHARE: Download: Full Size (0.06 MB) Credit: VIRIN: 027141-M-PKP59-140.jpg Photo Gallery