04/14/2005. Remarks by Nico Braas: "Serving from 1925 as a fighter at the Czechoslovakian air force, the BH-21 proved to be very successfull. On this original photo made by a studio photographer from Prague, we see the first one. A total of 120 BH-21s was built. A further 39 were license-manufactured for the Belgian air force by the Belgian company SABCA."