 More test flights followed, and by 1934 the plane showed good results.Zmaj modified the FP-2 during 1934 using a Walter Pollux II engine, but the results were not satisfactory.The Zmaj Fizir FP-2 was a two-seater single-engine biplane aircraft, with air-cooled, 7 cylinder radial engine (Gnome-Rhone K-7 308 kW), and a pair of struts on each side.