The PIK-3c Kajava (Kittiwake) is a Finnish wooden single-seat glider developed by the Polyteknikkojen Ilmailukerho (Aviation Club of Polytechnic Students, PIK) in 1957 from the PIK-3b.
After OSTIV's 1957 decision to create the Standard Class for glider competitions made Olavi Roininen's PIK-14 project meaningless, Roininen reused his work to design a Standard Class competition version of the PIK-3b. The type was given the downsized wings of the PIK-13 prototype, and the rear fuselage and the vertical stabilizer were redesigned. The resulting aircraft, PIK-3c, made its first flight on 20 May 1958. The same year the prototype participated in the World Gliding Championships, reaching the fourth place.
Suomen Ilmailuliitto (Finnish Aeronautical Association) produced the PIK-3c, which it had named Kajava, in series. A total of 20 PIK-3cs were built, of which a few are still flying.
- Crew: 1
- Length: 6.6 m (21 ft 8 in)
- Wingspan: 15 m (49 ft 3 in)
- Mid wingspan: 1 m (3 ft 3 in)
- Height: 1 m (3 ft 3 in)
- Wing area: 13.1 m2 (141 sq ft)
- Aspect ratio: 17.1
- Airfoil: Göttingen 549
- Empty weight: 165 kg (364 lb)
- Max takeoff weight: 280 kg (617 lb)
- Stall speed: 55 km/h (34 mph, 30 kn)
- Never exceed speed: 235 km/h (146 mph, 127 kn)
- Rough air speed max: 145 km/h (90.1 mph; 78.3 kn)
- Aerotow speed: 140 km/h (87.0 mph; 75.6 kn)
- Winch launch speed: 110 km/h (68.4 mph; 59.4 kn)
- Terminal velocity: with full air-brakes at max all-up weight 200 km/h (124 mph; 108 kn)
- g limits: +5 -2.5
- Rate of sink: 0.61 m/s (120 ft/min) at 65 km/h (40.4 mph; 35.1 kn))
- Lift-to-drag: 30:1 at 75 km/h (46.6 mph; 40.5 kn))
- Wing loading: 21.4 kg/m2 (4.4 lb/sq ft)