J.Zynk Polish Aircraft 1893-1939 (Putnam)
In the winter of 1909-10 Dipl Ing Jan Weber, lecturer at the Lwow Technical University, began studies for a completely original two-seat open-frame pusher biplane. The design, developed with the assistance of Prof Zygmunt Sochacki, was the first Polish project to have the overall concept and all details calculated mathematically and fully investigated theoretically before construction began.
Building of the airframe, which incorporated various changes and refinements as compared with the original study, was delayed by lack of necessary capital, but in June 1910, the Aircraft Building Share-holders Company was established (staff and students of the Lwow Technical University forming the major proportion of its members) and this company provided financial backing for the enterprise and launched a subscription fund. The partially completed machine was displayed at the First Aviation Exhibition in Lwow, which was staged at the University from 1 September to 15 October, 1910.
Powered by a 50 hp Korting four-cylinder water-cooled inline engine driving a two-blade pusher Drzewiecki airscrew, Weber's biplane was ready for its first flight in the late autumn of 1910. The attempt, which presumably took place in November, was undertaken by the designer (who had no experience as a pilot) in Blonia Janowskie in the presence of a large group of students from the Machine Building Faculty who helped with the construction work, but this ended in a mishap. The aircraft left the ground, but seconds later collided with a tree and was severely damaged, its pilot escaping with cuts and bruises. It was decided to defer further trials until the following spring, and the repaired airframe was stored in a shed for the winter. Unfortunately, the shed collapsed under the weight of snow and the machine was completely crushed.
Construction: Weber's aircraft was a two-seat unequal-span two-bay biplane, built mainly of ash with the addition of certain steel-tube elements. The wings, of double-surfaced type, had an area of 40 sq m (430.5 sq ft). The top wing, with a chord of 1.8 m (5 ft 11 in), featured coarsely dihedralled tips. The bottom wing had a span of 10 m (32 ft 9 3/4 in) and chord of 2 m (6 ft 7 in), with its leading edge projecting forward of that of the top wing. Two aileron surfaces were carried on wires in front of the top wing. The fuselage was an open framework trussed with wires. The pilot's position, equipped with a control wheel and rudder bar, was situated between the wings, the passenger sitting behind the pilot. The engine, mounted on struts, was further aft. The tail unit consisted of a rudder and a fixed tailplane with a span of 5 m (16 ft 5 in) and chord of 1.2 m (3 ft 11 1/2 in). The elevator, of the same overall span including its fixed tips, was carried on forward outriggers in front of the top wing. The landing gear comprised two mainwheels, attached by rubber cords to wooden skids, and a tailwheel. Overall dimensions included a span of 12 m (39 ft 4 3/4 in), length of 11.5 m (37 ft 9 in) and height of 3.5 m (11 ft 6 in). Empty and maximum loaded weights were 310 kg (683 lb) and 500 kg (1,102 lb).