Schempp-Hirth Standard Cirrus
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The Standard Cirrus is a Standard-class glider built in Germany by Schempp-Hirth. The Standard Cirrus was produced between 1969 and 1985, when the Discus replaced it. Over 800 examples were built, making it one of the most successful early fibreglass glider designs.
Development
Dipl Ing designed the Standard Cirrus. Klaus Holighaus flew for the first time in February 1969. It is a Standard Class glider with a 15-metre span and laminar-flow airfoil section designed by Professor Franz Wortmann. The all-moving tailplane, a feature of many designs of that period due to its theoretically higher efficiency, caused less than desirable high-speed stability characteristics, so modifications were made to the early design. The aircraft built before 1972 have a washout of -0.75 degrees. The washout was then increased to -1.5 degrees, improving low-speed performance and slow-speed response.[1]
Improvements were made to the Standard Cirrus 75. These included better air brakes with an increased frontal area and a safer tailplane attachment system. By April 1977, when production of Schempp-Hirth ended, 700 Standard Cirruses had been built, including 200 built under licence by Grob between 1972 and July 1975. A French firm, Lanaverre Industrie, had also built 38 Standard Cirruses under licence by 1979. VTC of Yugoslavia also licensed-built Standard Cirruses, reaching approximately 100 by 1985.
Variants
- Baby Cirrus
The Baby Cirrus is similar to a Standard Cirrus 75. The only difference is that the Baby Cirrus had its wing on top of the fuselage, mounted on a fiberglass beam of some sort. Only one was made. It was primarily used to try to improve the design of the Standard Cirrus. The original registration was D-3111. It was later converted to a Standard Cirrus 75 and was given a new registration. It is still flying to this day and is owned by a club in Germany.
- Cirrus B
The Cirrus B is based on the Standard Cirrus 75 but with interchangeable wingtips, giving a span of either 15m or 16m.
- Cirrus K
The two Cirrus K have a reduced span (12.6m), larger ailerons, a cross tail with a larger elevator, and a strengthened fuselage, which makes them suitable for aerobatics. This modification was initiated by Wilhelm Düerkop in the late 1980s.[2][3] Wolfgang Seitz participated in the 1995 World Glider Aerobatic Championships with a Cirrus K.[4]
- G/81
The last Cirrus model was the G/81 built by VTC until 1985. This incorporated a longer fuselage and canopy and a conventional tailplane and elevator with the wings of the Cirrus 75.
Specifications
See also
Related development
Aircraft of comparable role, configuration, and era
Related lists
References
Citations
Bibliography
- Schempp-Hirth Website
- Coates A., Janes World Sailplanes and Motor Gliders, Janes,1980, Template:ISBN, pg. 85
- Simons M, Segelflugzeuge 1965–2000, Eqip, 2004
- Sailplane Directory
- American narrative of World Championships (see 1968).