Federal aviation officials have explained the mysterious flying object seen in the Amherst area this month — sort of. A Federal Aviation Administration spokesman said a military aircraft was flying over Amherst on Jan. 8 at about the time residents reported seeing the UFO flying silently overhead. The spokesman told The Daily Hampshire Gazette that the giant C5 cargo plane was doing practice approaches to Westover Air Reserve Base. The UFO was described by witnesses as triangular or diamond-shaped, the size of two or three cars, flying slow and silent. That does not jibe with a C5, which is almost 250 feet long and extremely loud.