Boeing announced on December 3, 2007, that it has been awarded a USD 45 million U.S. Air Force contract to upgrade the B-1B bomber's avionics software. The contract continues the U.S. Air Force's avionics software upgrade program to ensure its 67 strong B-1B bomber fleet have the latest software improvements, continuously expanding the bomber's potential. The program consist of annual "Sustainment Blocks", the current upgrade is designated Sustainment Block 14.