Schempp-Hirth Standard Cirrus
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|First flight||02 / 20 / 1969|
|Number built||ca. 838|
The Standard Cirrus was designed by Dipl. Ing. Klaus Holighaus and flew for the first time in March 1969. It is a Standard Class glider with a 15-metre span and no camber-changing flaps. 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, and so modifications were made to the early design. Even so, the glider is still very sensitive in pitch. The aircraft built before 1972 have a washout of -0.75 degrees. The washout was then increased to -1.5 degrees which improved low-speed performance and response at slow speed.
Improvements were made with the Standard Cirrus 75. These included better air-brakes with an increased frontal area. By April 1977, when production by Schempp-Hirth ended, a total of 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 licence-built Standard Cirruses, reaching approximately 100 by 1985.
All models of Cirrus have proved very popular in recent years in Club Class Competitions worldwide.
The Cirrus was superseded by the Discus in 1984.
- 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 larger elevator, and a strengthened fuselage which make them suitable for aerobatics. This modification was initiated by Wilhelm Düerkop in the late 1980s. Wolfgang Seitz took part in the 1995 World Glider Aerobatic Championships with a Cirrus K.
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.
Data from Jane's all the World's Aircraft 1976–77 
- Crew: 1
- Capacity: 80 kg (180 lb) water ballast
- Length: 6.35 m (20 ft 10 in)
- Wingspan: 15 m (49 ft 3 in)
- Height: 1.32 m (4 ft 4 in)
- Wing area: 10 m2 (110 sq ft)
- Aspect ratio: 22.5
- Airfoil: root: Wortmann S-02-196 (19.6%) ; tip: Wortmann FX 66-17A II 182 (17%)
- Empty weight: 215 kg (474 lb)
- Max takeoff weight: 390 kg (860 lb) with water ballast
- 330 kg (730 lb) without water ballast
- Stall speed: 62 km/h (39 mph, 33 kn)
- Never exceed speed: 220 km/h (140 mph, 120 kn)
- Max aerotow speed: 150 km/h (93 mph; 81 kn)
- Max winch launch speed: 120 km/h (75 mph; 65 kn)
- g limits: +10
- Maximum glide ratio: 38.5:1 at 90 km/h (56 mph; 49 kn)
- Rate of sink: 0.6 m/s (120 ft/min) at 71 km/h (44 mph; 38 kn)
- Wing loading: 39 kg/m2 (8.0 lb/sq ft) with water ballast
- 33 kg/m2 (6.8 lb/sq ft) without water ballast
Aircraft of comparable role, configuration and era
|Wikimedia Commons has media related to Schempp-Hirth Standard Cirrus.|
- Standard Cirrus Wing Twist
- Swiss Glider Aerobatics Association's Cirrus K website (in German)
- List of planes and gliders of the "Toy Team" (in German) Archived 2011-10-03 at the Wayback Machine
- FAI pilot profile of Wolfgang Seitz[permanent dead link]
- Taylor, John W.R., ed. (1976). Jane's all the World's Aircraft 1976–77 (67th ed.). London: Jane's Yearbooks. p. 566. ISBN 0-3540-0538-3.
- Lednicer, David. "The Incomplete Guide to Airfoil Usage". m-selig.ae.illinois.edu. Retrieved 16 April 2019.