The Thomas-Morse MB-3 was an open-cockpit biplane fighter primarily manufactured by the Boeing Company for the U.S. Army Air Service in 1922. The MB-3A was the mainstay fighter for the Air Service between 1922 and 1925.
The Tupolev ANT-21 was a Soviet twin-engined four-seat heavy fighter, which also had the designation MI-3 (Mnogomestnyi Istrebitel – Multi-seat fighter). It was not accepted for production, only two prototypes being built.
