On Dec 14, 7:55*pm, Eric Greenwell wrote:
Herb wrote:
Another useful approach is start at about 66% aft using manufacturer's
CG range. When making the tightest turn you normally do, if you run
out of elevator, you need to shift CG back a bit. You will probably
end up around 75%.There isn't a huge benefit in having the CG way
back, but there is a significant deterioration of handling which
requires better pilot skills to offset.The last little bit of glider
performance costs quite a bit in pilot workload until you are very
proficient. I usually take a couple pounds out of the tail in the
Spring and put it back in when my skills are back up to snuff.
FWIW
UH

Here's another gem piece of advice: With my 3D model airplanes I roll
inverted and check if I need down elevator to stay level. *If so, the
cg needs to be moved further back. *A well set up model will happily
fly inverted without elevator movement! *Haven't tried that in my LS8,
though.
Seriously, *Hanks and Eric's methods will both work well. *As long as
inside the book range, find the cg that gives you good handling and
enough up elevator to stall the plane in a steep turn. *It'll be at
75%-90% aft.

Why is the ability to stall in a steep turn a useful criteria? It sounds
like a safety problem to me.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly- Hide quoted text -

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Gives adequate pitch authority to pull to max lift coefficient, thus
tightest turn. From my experience, this is usually about 75-80% aft in
manufacturer's approved range.
UH