J.Zynk Polish Aircraft 1893-1939 (Putnam)
Glider of the Chrzanowski Secondary School Students
Students of the Chrzanowski Secondary School in Warsaw, inspired by the first flight attempts of Legagneux in their city, formed an 'Aviation Circle' in the latter part of 1909 and began to construct flying models. Its most active members, Waclaw Jedrzejewicz, Leonard Mozdzehski, Waclaw Niwinski and Lech Niemojewski (who voluntarily helped Zbieranski and Cywinski to built their biplane in the Aviata hangar) evolved a rudimentary man-carrying biplane glider, the design of which was based upon Michal Krol's book How to Build a Glider.
The glider was constructed in Jeziorna near Warsaw, in a shed belonging to a paper factory which was put at the disposal of young enthusiasts free of charge, and tested from the slopes of the small hills in Klarysew during the 1912 summer holidays. The craft, which made a number of steady glides, appeared to be one of the most successful devices in its class in Poland in this early era. Jedrzejewicz, who was the lightest of the four students, covered on occasions distances of 200-300 m (656-984 ft) at a stretch, gliding sometimes to a height of some 20 m (65 ft). Unfortunately, during the last of these flights, a bamboo rest supporting the pilot snapped, the glider lost stability and crashed. Jedrzejewicz received cuts and heavy bruises and the aircraft was never rebuilt.
Construction: The glider was an equal-span biplane constructed of bamboo and trussed with wires. The wings and cellular-type tail bay were of single-surfaced type, a cambered aerofoil section being employed. A single, open vertical frame formed the fuselage. The pilot hung in the uncovered centre section of the lower wing and controlled the balance by swinging his suspended body. The craft had a span of 7.6 m (24 ft 11 1/2 in) and its empty weight was 25 kg (55 lb).