The PIK-3 (Polyteknikkojen Ilmailukerho – Finnish institute of technology students flying club) was a sailplane produced in Finland in the 1950s and 60s.[1] It was designed to be a cheap and easy-to-build aircraft[2] to equip the country's gliding clubs as their standard single-seat machine.[3] It was a conventional design for its day, with a high wing and conventional empennage.[2][3] Construction was of wood throughout, skinned in plywood.[2][3]

PIK-3
PIK-3a in Finnish Aviation Museum
Role Sailplane
National origin Finland
Manufacturer Polyteknikkojen Ilmailukerho
Designer Lars Norrmen and Ilkka Lounama
First flight 1950
Number built 40

Design work commenced in 1942,[4] but the prototype did not fly until 1950.[2][3] Antti Koskinen refined the design for production as the PIK-3A and then further modified the design by replacing the flaps with air brakes, which was designated the PIK-3B.[2][3][4]

By the end of the 1950s, a third modification of the original design was carried out by Olavi Roininen[4] as the PIK-3C. This had completely new wings of 15 m (49 ft 3 in) to allow it to compete in the Standard Class.[2] The prototype flew on 20 May 1958,[2][3] and the design was then modified for production by Suomen Ilmailuliitto.[3]

Variants

edit
  • PIK-3 – first prototype with wingspan of 13 m (47 ft 8 in)
  • PIK-3A Kanttikolmonen – initial production version of PIK-3
  • PIK-3B – PIK-3A with air brakes in place of flaps
  • PIK-3C Kajava – PIK-3B with new wings of 15 m (49 ft 3 in) span

Specifications (PIK-3c)

edit

Data from Jane's World Sailplanes and Motor Gliders,[2] The World's Sailplanes:Die Segelflugzeuge der Welt:Les Planeurs du Monde[5]

General characteristics

  • Crew: 1
  • Length: 6.6 m (21 ft 8 in) (PIK-3 – 6.5 m (21 ft 4 in))
  • Wingspan: 15 m (49 ft 3 in) (PIK-3 – 13 m (42 ft 8 in))
  • Mid wingspan: 1 m (3 ft 3 in)
  • Height: 1 m (3 ft 3 in)
  • Wing area: 13.1 m2 (141 sq ft) (PIK-3 – 13 m2 (140 sq ft))
  • Aspect ratio: 17.1 (PIK-3 – 13)
  • Airfoil: Göttingen 549 (PIK-3 – Göttingen 693)
  • Empty weight: 165 kg (364 lb) (PIK-3 – 135 kg (298 lb))
  • Max takeoff weight: 280 kg (617 lb) (PIK-3 – 240 kg (530 lb))

Performance

  • Stall speed: 55 km/h (34 mph, 30 kn)
  • Never exceed speed: 235 km/h (146 mph, 127 kn) (PIK-3 – 200 km/h (124.3 mph; 108.0 kn))
  • Rough air speed max: 145 km/h (90.1 mph; 78.3 kn) (PIK-3 – 130 km/h (80.8 mph; 70.2 kn))
  • Aerotow speed: 140 km/h (87.0 mph; 75.6 kn) (PIK-3 – 130 km/h (80.8 mph; 70.2 kn))
  • Winch launch speed: 110 km/h (68.4 mph; 59.4 kn) (PIK-3 – 100 km/h (62.1 mph; 54.0 kn))
  • Terminal velocity: with full air-brakes at max all-up weight 200 km/h (124 mph; 108 kn) (PIK-3 – 180 km/h (111.8 mph; 97.2 kn))
  • g limits: +5 -2.5 (PIK-3 – +4 -2)
  • Rate of sink: 0.61 m/s (120 ft/min) at 65 km/h (40.4 mph; 35.1 kn)) (PIK-3 – 0.76 m/s (149.6 ft/min) at 61 km/h (37.9 mph; 32.9 kn))
  • Lift-to-drag: 30:1 at 75 km/h (46.6 mph; 40.5 kn)) (PIK-3 – 25:1 at 72 km/h (44.7 mph; 38.9 kn))
  • Wing loading: 21.4 kg/m2 (4.4 lb/sq ft) PIK-3 – 18.5 kg/m2 (3.79 lb/sqft)

See also

edit

Aircraft of comparable role, configuration, and era Schleicher Ka-6

Notes

edit
  1. ^ Taylor 1989, p.726
  2. ^ a b c d e f g h Coates 1978, p.24
  3. ^ a b c d e f g Hardy 1982, p.74
  4. ^ a b c "PIK-sarjan lentokoneet"
  5. ^ 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. 9–13.

References

edit
  • 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. 9–13.
  • Hardy, Michael (1982). Gliders and Sailplanes of the World. Shepperton: Ian Allan.
  • Coates, Andrew (1978). Jane's World Sailplanes and Motor Gliders. London: MacDonald and Jane's.
  • "PIK-sarjan lentokoneet". Polyteknikkojen Ilmailukerho website. Retrieved 2009-01-08.
  • Taylor, Michael J. H. (1989). Jane's Encyclopedia of Aviation. London: Studio Editions.