12/31/2012. Some redesign and minor strengthening of the BH-3
(site files) forward fuselage was undertaken in 1922 to permit installation of the 220 hp Hispano-Suiza 8ba eight-cylinder water-cooled V-engine in place of the six-cylinder upright BMW engine. Apart from the forward fuselage, a taller turnover pylon aft of the cockpit and a modified undercarriage with larger mainwheels, the HS-powered aircraft, initially designated B-HS-3 and subsequently BH-4, was essentially similar to the BH-3, and intended armament comprised two 0.303 in (7.7 mm) Vickers guns. Performance of the BH-4 proved to be marginally inferior to that of the earlier fighter and development was confined to a single prototype.