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Old January 30th 16, 02:06 AM posted to rec.aviation.soaring
Martin Gregorie[_5_]
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Default Akaflieg Karlsruhe AK-X

On Fri, 29 Jan 2016 23:39:37 +0000, Paul T wrote:

If you have FSX or FS2004 you can also fly the SB13. Download he
http://simviation.com/1/browse-Glide...tralites-130-5 Seem to
remember reading the SB13 was fairly tricky to fly hence it's early
retirement, and the performance was somewhat disappointing.


Yes, indeed. The students spend 6 years working on a 1/3 scale RC model
and building it, followed by another 2 years making modifications and
retesting the aircraft, but they found that it remained tricky to fly
(stalls with a rear CG usually resulted in a spin and stalls with a
forward CG resulting in the glider 'pecking'. Unless spin recoveries were
very precise the glider often flicked into the opposite spin instead of
recovering. Its behavior on tow was diabolical, it was very tricky to fly
and, as its performance was no better than contemporary Standard Class
gliders they gave it up as a bad job and put it in a museum.

'pecking' was a large amplitude, rapid pitching cycle whose causes and
mitigation were never understood.

FWIW this is a rapid summary of the two page description in "Sailplanes
1965-2000", which also includes an excellent colour photo and a full
page, dimensioned 3-view drawing of the SB-13.


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