Designed during 1928, the carrier-based F4B-series for the U.S. Navy and the similar P-12 for the U.S. Army were the most widely used fighter/bomber biplanes between the two world wars. The P-12E had a duraluminum fuselage and a top speed of 194 mph. The U.S. Army order for 135 P-12Es in 1930 was the Boeing Company’s largest order in ten years.