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. Model 83, designed for the Navy, had a hook-type arrester so that it could land on aircraft carriers. Its production version was designated F4B. The Model 89, built for the Army as the P-12, had a rack that could hold a 500-pound bomb.