On Feb 15, 12:27*am, Andy wrote:

I'm trying to
figure out the circumstances under which someone would try to achieve
best L with the brakes out rather than just retracting the brakes.

Well I know of one case for an L13. The pilot didn't realize the
brakes were open so closing them was never on the list of things to
try. (No it wasn't me).

Agree that the OP needs to better define what data is needed, but it
still may not be available. Somewhere in my logs I have data for max
achieved sink rates for the ASW-19 and ASW-28. I did tests with full
brakes and with full brakes and full rudder slips. It's amazing how
quick you can get a glider to come down if you really want to. I found
the feeling of hanging on the brakes at 80kts to be quite
uncomfortable though and never tried speeds much higher than that.

What is more useful to know is how to get the max descent angle while
still maintaining minimum safe approach speed. For the 19 and 28,
full brakes and full rudder slip is very effective. Try it at
altitude first to get used to controlling speed with only pitch
attitude as the indicated airspeed may be zero.

Andy