The FB series of U.S. Navy fighters began with the Boeing Model 15 prototype in 1923. The Army procured several examples of the promising design, which it designated the PW-9. The Navy closely followed the Army's testing of the aircraft and added an order for 14 to an Army contract in late 1924. The Navy designated their airplane the FB 1. The FB-2, FB-3, and FB-4 were simply FB-1s modified to test different components.The major production model of the series was the FB-5, which differed considerably from earlier models. Visibility and control problems were corrected by altering the wing stagger and installing a balanced rudder, along with other changes. The FB-5 displayed here served aboard the U.S.S. Langley and Saratoga. It was assigned to Marine Fighter Squadron VF-6M for several months in 1930.