Col. David Lujan (left), 56th Operations Group deputy commander, shares a laugh with Brig. Gen. Kurt Neubauer, 56th Fighter Wing commander at Luke Air Force Base, Ariz., Dec. 22, moments after he completed his 4,000th hour in the F-16 Fighting Falcon. He is the 17th pilot to reach this milestone. (U.S. Air Force photo/Tech Sgt. Jeffrey A. Wolfe)