11/30/2011. With the trainer derivatives of the NA-16 firmly established in production by 1938, North American investigated a number of ways in which the versatility of the basic design could be extended. This line of development resulted in a single-seat fighter, with a shorter wing and more powerful engine, but recognizably a relative of the AT-6 Harvard in appearance.

As the NA-50, seven examples of this fighter were ordered by Peru in January 1938, delivery being completed in May 1939. The engine was an 870 hp Wright R-1820-G3 Cyclone driving a three-blade constant-speed propeller, and the armament comprised two 0.30 in (7.62 mm) Colt machine guns in the cowling and provision for 550 lb (249 kg) of bombs. Fuselage construction was of metal, and the 170 gal (644 l) of fuel was carried in integral tanks. Ring and bead sights were fitted ahead of the cockpit.

The Torito (Bull) saw brief operational service in 1941 when the Cuerpo de Aeronautica del Peru, as the Fuerza Aerea Peruano (Peruvian AF) was then known, was in action against Ecuador. The last Peruvian NA-50 was withdrawn in 1961. One aircraft that remained in 1965, s/n 251, was put on a pedestal at Las Palmas as a memorial to Teniente (Lieutenant) Jose Quiñones. Quiñones lost his life on July 23, 1941, after being hit by Ecuadorian anti-aircraft fire the engine stopped and Quino crashed his bomb-loaded aircraft into the anti-aircraft gun battery.