This U.S. Department of Commerce study responds to a request by Congress to examine market developments and government policies influencing the competitiveness of the United States jet transport aircraft industry. Section 819 of the "Vision 100-Century of Aviation Reauthorization Act" (P.L. 108-176) established the objectives of the study. The report focuses primarily on U.S. and European manufacturers of civil jet transports with 100 seats or more (referred to as large civil aircraft or LCA), as well as of the engines and major subsystems for those aircraft.