PZL Bielsko IS-5

IS-5 Kaczka
Type:	Glider
Design country:	Poland
Manufacturer:	Szybowcowy Zakład Doświadczalny (SZD)
First flight:	March 29, 1949
Number of pieces:	1

The PZL Bielsko IS-5 Kaczka ( German  duck ) was a Polish experimental glider in duck design from 1949.

history

In 1948, the Bielsko team of the “Test Company for Gliders” (Szybowcowy Zakład Doświadczalny, SZD) started researching new glider designs. The first attempt was the unusual design by engineers Tadeusz Kostia and Irena Kaniewska (1914–1963), with which the first hopper was achieved in March 1949. However, the aircraft only turned out to be airworthy after a few modifications and the first aircraft tows could then be carried out. The first flight took place on March 29, 1949 with the pilot Piotr Mynarski in a winch launch with a towing height of only 10 m. After changing the center of gravity, the aircraft was flown in.

Only one example was built (registration number SP-821), but it was tested in five different configurations. In 1951 the test flights had to be stopped due to time constraints and could only be continued in 1957 (or 1959). The aircraft was destroyed in a major fire in the hangar of the Łódź Aeroclub in 1961. A total of 117 flights with a total flight time of 35 hours were completed in all weather conditions ( slope flight , thermal flight , cloud flight , wave flight ). Despite the unusual design, the pilots had a good opinion of the flight characteristics.

construction

The aircraft was a duck construction made of wood . A special feature was the tail cone of the fuselage nacelle, which could be unfolded in a vertical split to serve as an aerodynamic brake . The wing end disks served both as aerodynamic brakes (deflection in opposite directions, synchronous) and as rudder (joint deflection in the same direction). In one configuration, the end plates were enlarged by riveted aluminum sheets. Similarly, attempts have been made to improve the effect of the elevators . The hinged tail cone proved to be insufficiently effective in its function as an aerodynamic brake and so its drive spindle was used to move a 15 kg weight in order to be able to investigate the shift of the center of gravity in flight via cables.

Technical specifications

Parameter	Data
crew	1
length	4.00 m
span	11.56 m
height	2.20 m
Wing area	10 m²
Empty mass	120.7 kg
Wing loading	29.5 kg / m²
Max. Takeoff mass	205.7 kg
Glide ratio	19.6 at 82 km / h
Rate of descent	1.26 m / s at 76 km / h
Minimum speed	63 km / h
Top speed	180 km / h

See also

• List of aircraft types

literature

• Martin Simons: Gliders - 1945 to 1965 . 2nd Edition. Eqip Werbung & Verlag GmbH, Königswinter 2006, ISBN 3-9807977-3-2 , p. 101 f .
• Kazimierz Wojciech Chudzinski: Polish gliders . Volume 1: 1945-1970. Verlag für Technik und Handwerk, Baden-Baden 2014, ISBN 978-3-88180-454-7 .
• Leonard Bridgman (Ed.): Jane's All The World's Aircraft 1950–1951 . Samson Low, Marston & Company, Ltd., London 1950, p. 165 f . (English).

Web links

Commons : IS-5 Kaczka  - collection of pictures, videos and audio files

Individual evidence

1. ^ Simons, 2006
2. ^ IS-5 Kaczka. July 16, 2004, accessed on March 2, 2016 : "The experimental sailor" Kaczka "was designed by Ing.T. Kostia and Ing.I. Kaniewska."