Schempp-Hirth Discus

__NOTOC__ Infobox Aircraft
name=Discus


caption=A Czech-built Discus CS at Eindhoven, Netherlands.
type=Standard-class sailplane
manufacturer=Schempp-Hirth
designer=Klaus Holighaus
first flight=
introduced=
retired=
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primary user=
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produced=
number built=>850
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The Schempp-Hirth Discus is a Standard Class glider designed by Schempp-Hirth. It was produced in Germany between 1984 and 1995 but has continued in production in the Czech Republic. It replaced the Standard Cirrus. It was designed by Klaus Holighaus.

The Discus was the first production sailplane to have a distinctive swept back leading edge- now fairly common in contemporary gliders.

Studies had long shown that the ideal wing for minimizing induced drag should be an elliptic planform. To keep production costs down, a triple-trapezoidal approximation of this shape was adopted for the Discus. The wing section was also new. Winglets were only available towards the end of the production run, though many have been retro-fitted. The fuselage and tail were adapted from the Schempp-Hirth Ventus. A version with a narrow fuselage is called the Discus 'a' and the wider fuselage version is called the 'b'. The fuselage is made of glass reinforced plastic around a steel tube frame. The wings and tail surfaces are also fiberglass with the exception of the main wing spar, which is made of carbon fiber. There is a 6,5L water ballast tank in the fin for trimming purposes when the main wing mounted ballast tanks are in use (184L combined), for a maximum load of ~50kg/m2

The Discus dominated standard class sailplane racing throughout the 1980s, winning the 1985, 1987 and 1989 World Gliding Championships. Over 20 years after its introduction, it remains competitive today. In the 1999 United States Standard Class Nationals, Discus A models finished First, Third and Sixth. Another "A" model was flown to 2nd place in the 2002 US Standard Class Nationals.

The best measured glide ratio is 42.5:1. Though it is considered a high performance sailplane, its handling is well within the capabilities of inexperienced pilots. With no bad manners, powerful airbrakes and a low landing speed, the Discus is popular with clubs. Discuses [cite book |last= Burchfield |first= Robert |title= Fowler's Modern English Usage|publisher= Oxford University Press |year= 1996 |id = ISBN 0-19-869126-2 ] are easy gliders to assemble, having light wings, automatic control hookups and a single pin securing the wings.

Over 850 Discuses had been built by 2004 and it remains in production today despite the introduction of its successor, the Schempp-Hirth Discus-2. About 12 per year are built under license by Schempp-Hirth Vyroba in the Czech Republic as the Discus CS. Some models are fitted with small sustaining engines (turbos) and are designated Discus T.

pecifications (Discus b)

aerospecs
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met or eng?= met

crew=One pilot
capacity=
length m=6.58
length ft=21
length in=7
span m=15.00
span ft=49
span in=3
swept m=
swept ft=
swept in=
rot number=
rot dia m=
rot dia ft=
rot dia in=
dia m=
dia ft=
dia in=
width m=
width ft=
width in=
height m=1.30
height ft=4
height in=3
wing area sqm=10.58
wing area sqft=113.9
swept area sqm=
swept area sqft=
rot area sqm=
rot area sqft=
volume m3=
volume ft3=
aspect ratio= 21.3
empty weight kg=230
empty weight lb=510
gross weight kg=525
gross weight lb=1,160
lift kg=
lift lb=

eng1 number=
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eng1 hp=
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eng2 number=
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max speed kmh=250
max speed mph=155
max speed mach=
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cruise speed mph=
range km=
range miles=
endurance h=
endurance min=
ceiling m=
ceiling ft=
glide ratio= 42.5
climb rate ms=
climb rate ftmin=
sink rate ms= 0.59
sink rate ftmin= 116

armament1=
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armament6= aircontent
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References

* [http://www.schempp-hirth.com/ Schempp-Hirth Website]
*Simons M, Segelflugzeuge 1965-2000, Eqip, 2004
* [http://www.sailplanedirectory.com/PlaneDetails.cfm?planeID=87 Specifications of Schempp-Hirth Discus]
* Soaring Society of America

External links

[http://www.gliding.co.uk/bgainfo/technical/datasheets/discus.pdf British Gliding Association, Discus datasheet]