The PIK-20

sailplane A glider or sailplane is a type of glider aircraft used in the leisure activity and sport of gliding (also called soaring). This unpowered aircraft can use naturally occurring currents of rising air in the atmosphere to gain altitude. Sailplan ...

was designed at the

Helsinki University of Technology Helsinki University of Technology (TKK; ; , HUT in international usage) was a technical university in Finland. It was located in Otaniemi, Espoo in the Helsinki metropolitan area, and it was one of the three universities from which the modern d ...

by Pekka Tammi, with advice from Ilkka Rantasalo and Raimo Nurminen. The prototype first flew on 10 October 1973. It was produced initially by Molino Oy who were taken over by Eiri-Avion Oy (currently Eirikuva Oy) between 1974 and 1980. Later, production was taken over by the French company, Siren SA, under the name Siren PIK-20. At first the PIK-20 was classified as a Standard Class glider, which at the time allowed either flaps or air-brakes for landing approach control. The specification of the Standard Class required the air-brakes or flaps to be capable of keeping the speed below the maximum speed in a vertical dive. However at high speed great force was needed to fully lower the flaps and so the PIK-20 was equipped with a geared crank handle. The first prototype finished 13th in the

World Gliding Championships The World Gliding Championships (WGC) is a gliding competitions, gliding competition held roughly every two years by the FAI Gliding Commission. The dates are not always exactly two years apart, often because the contests are always held in the sum ...

in Waikerie in January 1974 but it performed impressively. (The low placing was caused by a poor decision on the first day of the competition.) This yellow prototype glider (OH-425) can be seen in movie named "Zulu Romeo - Good start" about this 1974 World Gliding Championship. The glider was then produced at the rate of two to three per week. The rules of the Standard Class were changed again to allow the flaps and ailerons to move together (flaperons) and for intermediate settings of the flaps between landing mode and zero. The result was the PIK-20B which won British, American and Finnish National Championships in 1975. In 1976 Ingo Renner won the World Championship with a PIK-20B and second and third places were also taken by this type. Most owners of PIK-20A converted to the B's flaperon arrangements.

Carbon fiber Carbon fiber-reinforced polymers (American English), carbon-fibre-reinforced polymers ( Commonwealth English), carbon-fiber-reinforced plastics, carbon-fiber reinforced-thermoplastic (CFRP, CRP, CFRTP), also known as carbon fiber, carbon comp ...

spars later became standard. Another change in the rules prohibited lift-enhancing devices in the Standard Class; and introduced a racing class or 15-metre class which did permit lift-enhancing devices. As a result, the PIK 20D with trailing-edge flaps was produced for the new 15-metre class. PIK-20 C-FBMK

The PIK-20s were also notable for being conventionally painted rather than using gel-coat. (The prototype was bright yellow.) This type of finish is longer-lasting and simpler to repair. The name PIK is an acronym for

Polyteknikkojen Ilmailukerho Polyteknikkojen Ilmailukerho (PIK) is the student flying club of the Aalto University. As well as a flying club, it develops light aircraft and gliders, often on a small scale but sometimes its designs have been produced in quantity. Approximately ...

, the flying club of the Student Union of Helsinki University of Technology. A fire in the factory June 1977 dented production briefly but by then 200 gliders had been sold. Production continued until about 1985 with the D and E versions with over 400 examples of the type having been completed.

Variants

;PIK 20 Prototype and initial production version. 400 kg gross weight. Retrofit of PIK-20B flap-aileron interconnect permitted under a service bulletin. Retrofit of PIK-20B enlarged water ballast bags and corresponding 450 kg gross weight permitted under a service bulletin. ;PIK 20B Refined standard class sailplane with interconnected flaps and ailerons. Gross weight increased to 450 kg. ;PIK 20C Proposed version with airbrakes and no flaps. ;PIK 20D PIK 20D added conventional Schempp-Hirth airbrakes, carbon reinforcement strips at critical locations in the fuselage, the nose profile was sharpened, the tail-plane was moved forward and fuselage fairings recontoured to reduce drag. The flaps were limited to -12 to +20 degrees. The first flight of the D was in 1976. ;PIK 20E The self-launching PIK-20E is similar to the D model, but has a retractable Rotax 501 that takes 15 turns of a manual crank in the cockpit to deploy or retract. The fuselage is slightly different, with a slight sweep-back of the wings and the tailplane is larger. The modifications to turn the PIK-20 into a motorglider were designed by Jukka Tervamäki and the prototype first flew on 2 October 1976 as the Tervamäki JT-6 ;PIK 20E II F Designation for PIK 20Es produced by Siren S.A. in France. ;PIK-20F A PIK-20F had a modified wing profile, reshaped fuselage and a forward opening canopy. ;PIK-30 The Issoire Company in France produced a 17-metre PIK-30 version of the E. Unlike the PIK 20, the PIK 30 could not be winch-launched or fly with full negative flaps.

Specifications (PIK-20D)

References

Johnson R, A Flight Test Evaluation of the PIK-20, Soaring, September 1976
Johnson R, A Flight Test Evaluation of a PIK-20 Sailplane - A Further Evaluation, Soaring, July 1978 and August 1978
Johnson R, A Flight Test Evaluation of the PIK-20D, Soaring, January 1979
*Thomas F, Fundamentals of Sailplane Design, College Park Press, 1999 *Simons M, Segelflugzeuge 1965-2000, Eqip, 2004
Sailplane DirectoryPIK20 information site
{{Tervamäki aircraft 1970s Finnish sailplanes Glider aircraft Motor gliders Aircraft first flown in 1973 Mid-wing aircraft T-tail aircraft PIK aircraft Tervamäki aircraft