I didn't see specific reference to any one particular "tool" but here's a link to a VERY useful product <http://members.cox.net/evdesign/page...ge_design.html>. $10US for the electronic version but you gotta have Microsoft Excel.

You can plug/chug all the variouus parameters (e.g., control surface area, linkage properties, air speed, etc.) and see the resulting servo torque reqts. and all that as a function of control surface deflection and air speed. I use this program all the time to satisfy my own curiosity and to make sure servos I'm considering are up to the task imposed on them.

Mike