The Avia B.35 (RLM designation Av-35) was a fighter aircraft built in Czechoslovakia shortly before World War II. It was designed to meet a 1935 requirement by the Czechoslovakian Air Force for a replacement for their B-534 fighter biplanes. The B.35 was an elegant, low-wing monoplane with an elliptical wing. The fuselage was constructed from welded steel tube, covered in metal ahead of the cockpit and fabric aft, while the wing was of entirely wooden construction. Rather anachronistically, the Air Force specified a fixed tailwheel undercarriage for the aircraft, in the hope that this would speed development, as the mechanism for retracting the undercarriage was simply not yet available.