The Consolidated B-24 Liberator was an American four-engine heavy bomber used by the United States Army Air Forces (USAAF) and other allied air forces during World War II. Of the 19,256 B-24, PB4Y-1, LB-30 and other model variants in the Liberator family produced, thirteen complete examples survive today, two of which are airworthy. Eight of the thirteen aircraft reside in the United States.