twelve contestants. The contest was won by the D.K.D.4, piloted by Jozef Bargiel and the D.K.D.4bis, piloted by Karczmarczyk, came fifth. The D.K.D.3, flown by its designer, came third. The D.K.D.4's success in the Contest brought military interest in it as a trainer and an order for twenty-five was provisionally agreed. The Działowski brothers set up a company, Bracia Działowski, to manufacture them but the government failed to ratify the contract and only one production D.K.D.4 was completed. It had an active career, flying in contests and meetings with some success. The later D.K.D.5 was a fully aerobatic and final development of the D.K.D.4 design. It was powered by a Cirrus III four cylinder upright air-cooled inline engine mounted exposed. An aerodynamic clean-up included a divided undercarriage with cranked axles and a long oleo strut from the outer axle to the upper longeron on each side. Its wings were foldable and their span and area were 11% greater than the D.K.D.4. It first flew in July 1930, piloted by its designer. Despite a slight increase in weight over the D.K.D.4bis, the large increase of power and the clean-up raised its maximum speed to , gave it a ceiling of and enabled it to reach in six minutes. The D.K.D.5 did not reach the Warsaw Second International Tourism Challenge as it was badly damaged in an emergency landing after a fuel pipe broke during its flight to Warsaw. It was rebuilt and operated by the Kraków Aeroclub and competed in competitions and rallies. Variants W.K.D.4 LOPP example plus sole production airframe with Anzani 6 radial engine. W.K.D.4bis Kraków Aeroclub example with Siemens-Halske Sh 4 radial engine. W.K.D.5 Cleaned-up airframe with divided undercarriage and Cirrus III inline engine. Specifications (D.K.D.4bis) References Parasol-wing aircraft Single-engined tractor aircraft 1920s Polish sport aircraft Aircraft first flown in 1928