Big planes, yeah, in some form, but I don't remember anything other than general information about performance data vs. CG in the manuals for more than two dozen models of full-scale aircraft I have flown. Cruise and endurance info is given at a specified CG (worst-case, most forward normally), but I don't remember seeing charts plotting CG vs airspeed in airplane manuals. Gross weight has a bigger effect on cruise speed than CG normally. Of course I'll be the first to admit that I don't remeber every page of all two-dozen plus manuals I've used[sm=wink.gif].