The Avia BH-21, first flown in 1925, was a robust biplane that served an important role in securing Czechoslovak national security during the period between World War I and World War II. As well as being a competent fighter, it was also an accomplished racer, winning several air races in 1925.
The Aviatik D.VII was a German prototype single-seater fighter aircraft of the First World War, designed by Aviatik. Built to participate in the Third D-Type Contest of October 1918, it saw no military service. The only real major change from the D.VI was a completely new horizontal and vertical tail design.
