"Robert Davenport" wrote in message ...
I'm interested in knowing if anyone has any direct experience with the
increase in take-off run when launching a self-launch glider on grass? I'm
specifically interested in the performance of the Russia AC-5M, but would
enjoy hearing from anyone with grass-strip experience in any type of
self-launch glider. Thanks in advance..

That's going to depend a lot on the condition of the grass, i.e. short
and dry or long and wet. My DG-400 POH recommends adding 10% for grass
strips. But if it is soggy and long I would consider 25% to be more
realistic. That said, it isn't going to make a lot of diffence (100
ft, or so) unless you are at high altitude on a shorter strip.

Tom