The IS-4 was built for aerobatics with a high structural strength and a very high maximum speed which could not be achieved in a vertical dive. Due to the pilot's sitting position and the arrangements of the controls, it was difficult for pilots to exceed the 8g loading limit. During high speed flight it was possible for the air-brakes to be sucked out violently, so most pilots ensured that they remained closed by holding the airbrake control.[1]
^ abcdefPiechowski, Piotr. "IS-4 Jastrząb". Piotr & Renate Piechowski. Retrieved 19 April 2013.
^Shenstone, B.S.; K.G. Wilkinson (1963). The World's Sailplanes:Die Segelflugzeuge der Welt:Les Planeurs du Monde Volume II (in English, French, and German) (1st ed.). Zurich: Organisation Scientifique et Technique Internationale du Vol a Voile (OSTIV) and Schweizer Aero-Revue. pp. 172–173.
Piechowski, Piotr. "IS-4 Jastrząb". Piotr & Renate Piechowski. Retrieved 19 April 2013.
Shenstone, B.S.; K.G. Wilkinson (1963). The World's Sailplanes:Die Segelflugzeuge der Welt:Les Planeurs du Monde Volume II (in English, French, and German) (1st ed.). Zurich: Organisation Scientifique et Technique Internationale du Vol a Voile (OSTIV) and Schweizer Aero-Revue. pp. 172–173.
Further readingedit
Taylor, J. H. (ed) (1989) Jane's Encyclopedia of Aviation. Studio Editions: London. p. 29
External linksedit
Wikimedia Commons has media related to IS-4 Jastrząb.
jastrząb, instytut, szybownictwa, gliding, institute, single, seat, aerobatic, glider, designed, built, poland, from, 1949, role, glider, national, origin, poland, manufacturer, instytut, szybownictwa, designer, niespał, first, flight, 1949, introduction, 1950. The IS 4 Jastrzab Instytut Szybownictwa gliding institute was a single seat aerobatic glider designed and built in Poland from 1949 IS 4 Jastrzab Role Glider National origin Poland Manufacturer Instytut Szybownictwa Designer J Niespal First flight 21 Dec 1949 1 Introduction 1950 Number built 37 1 Contents 1 Development 2 Variants 3 Specifications IS 4 Jastrzab bis 4 See also 5 References 6 Further reading 7 External linksDevelopment editThe IS 4 was built for aerobatics with a high structural strength and a very high maximum speed which could not be achieved in a vertical dive Due to the pilot s sitting position and the arrangements of the controls it was difficult for pilots to exceed the 8g loading limit During high speed flight it was possible for the air brakes to be sucked out violently so most pilots ensured that they remained closed by holding the airbrake control 1 Variants editIS 4 Jastrzab two prototypes built in 1949 1 IS 4 Jastrzab bis Thirty five production aircraft three of which were exported 1 Specifications IS 4 Jastrzab bis editData from The World s Sailplanes Die Segelflugzeuge der Welt Les Planeurs du Monde Volume II 1 2 General characteristicsCrew 1 Length 6 25 m 20 ft 6 in Wingspan 12 m 39 ft 4 in Height 1 3 m 4 ft 3 in at cockpit Wing area 12 m2 130 sq ft Aspect ratio 12 Airfoil Root NACA 2418 Tip NACA 2412 Mid NACA 0012 Empty weight 240 kg 529 lb Gross weight 357 kg 787 lb Performance Stall speed 67 km h 42 mph 36 kn Never exceed speed 450 km h 280 mph 240 kn Rough air speed max 200 km h 120 mph 110 kn Aerotow speed 200 km h 120 mph 110 kn Winch launch speed 150 km h 93 mph 81 kn g limits 7 4 at 200 km h 120 mph 110 kn Maximum glide ratio 20 2 at 87 km h 54 mph 47 kn Rate of sink 1 04 m s 205 ft min at 70 km h 43 mph 38 kn Wing loading 29 7 kg m2 6 1 lb sq ft See also editAircraft of comparable role configuration and era Vogt Lo 100References edit a b c d e f Piechowski Piotr IS 4 Jastrzab Piotr amp Renate Piechowski Retrieved 19 April 2013 Shenstone B S K G Wilkinson 1963 The World s Sailplanes Die Segelflugzeuge der Welt Les Planeurs du Monde Volume II in English French and German 1st ed Zurich Organisation Scientifique et Technique Internationale du Vol a Voile OSTIV and Schweizer Aero Revue pp 172 173 Piechowski Piotr IS 4 Jastrzab Piotr amp Renate Piechowski Retrieved 19 April 2013 Shenstone B S K G Wilkinson 1963 The World s Sailplanes Die Segelflugzeuge der Welt Les Planeurs du Monde Volume II in English French and German 1st ed Zurich Organisation Scientifique et Technique Internationale du Vol a Voile OSTIV and Schweizer Aero Revue pp 172 173 Further reading editTaylor J H ed 1989 Jane s Encyclopedia of Aviation Studio Editions London p 29External links edit nbsp Wikimedia Commons has media related to IS 4 Jastrzab http www piotrp de SZYBOWCE pis4 htm https web archive org web 20100501051452 http kionastore com plan 1530 html http www vintagesailplanes de szd 4 htm Retrieved from https en wikipedia org w index php title IS 4 Jastrzab amp oldid 1200494289, wikipedia, wiki, book, books, library,
