The SZD-17X Jaskółka L (Swallow Laminar) drew on the experience gained from developing the SZD-11 and SZD-14X gliders combined with new laminar flow aerofoil sections and flaps, as well as provision for water ballast[1] and a fully retractable undercarriage.[2] Main designer was Tadeusz Kostia, main constructor Jan Dyrek.[3] Construction of the SZD-17X was of conventional wooden semi-monocoque fuselage and thick skinned wooden wings with wooden spars, retaining the Jerzy Rudlicki's butterfly tail of the SZD-14X. First flight of the SZD-17X took place at Bielsko airfield, flown by Adam Zientek, on 9 March 1956.[3]
Four aircraft, (reg'n no.'s SP-1504 to SP-1507), were built for use in 1956 World Gliding Championships, but performance fell short of expectations and they finally were not used there.[4] Despite the disappointing performance, Tadeusz Góra was able to establish a cross-country speed record on 9 May 1956 whilst flying SP-1506.[4] SP-1506 was used until 1977, then it was given to the Polish Aviation Museum.[5] The glider was nicknamed laminarka, due to its laminar flow profile.[6]
Specifications (SZD-17X Jaskółka L)
Data from The World's Sailplanes:Die Segelflugzeuge der Welt:Les Planeurs du Monde[1][7]
Rate of sink: 0.8 m/s (160 ft/min) at 87 km/h (47 kn; 54 mph)
Wing loading: 39.7 kg/m2 (8.1 lb/sq ft)
Note: A. Glass[6] quotes different specifications: maximum glide ratio 30.5 at 98 km/h; best sink rate 0.86 m/s at 93 km/h; wing loading 31.2 kg/m2 (40 with ballast).
See also
Aircraft of comparable role, configuration, and era
^Shenstone, B.S.; K.G. Wilkinson; Peter Brooks (1958). The World's Sailplanes:Die Segelflugzeuge der Welt:Les Planeurs dans Le Monde (in English, French, and German) (1st ed.). Zurich: Organisation Scientifique et Technique Internationale du Vol a Voile (OSTIV) and Schweizer Aero-Revue. pp. 124–128.
References
Shenstone, B.S.; K.G. Wilkinson; Peter Brooks (1958). The World's Sailplanes:Die Segelflugzeuge der Welt:Les Planeurs dans Le Monde (in English, French, and German) (1st ed.). Zurich: Organisation Scientifique et Technique Internationale du Vol a Voile (OSTIV) and Schweizer Aero-Revue. pp. 124–128.