Theoretical best approach speed?

How does the manufacturer of new gliders determine the
recommended best approach speed. ?

JAR 22 specifies the yellow triangle on the airspeed
indicator to be at the manufacturer's lowest recommended
approach speed at max weight without water ballast but I
can't find how that that speed should be determined.

I have thought that the minimum approach speed (-0- wind)
should be best L/D at max gross weight w/o water ballast so
that with half spoilers the pilot can be at an approach
angle half way between the best glide over the ground and
the steepest descent possible at that same constant airspeed
with full spoilers. (Wind would require additional speed.)

Does this analysis conform to what JAR or manufacturers' use
to determine the recommended minimum approach speed?

Thanks.


Pete





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Peter D. Brown
http://home.gci.net/~pdb/
http://groups.yahoo.com/group/akmtnsoaring/