Early in 1928, Boeing built two new fighter biplanes using bolted aluminum tubing for the fuselage's inside structure, rather than welded steel tubing, typical of earlier models. Later versions had aluminum covering the fuselage rather than fabric or wood. The military bought 586 of these fighters in different versions. Boeing built four commercial versions of the model; the U.S. Bureau of Air Commerce, precursor to the Federal Aviation Agency, bought one, and Howard Hughes bought a two-seat version.