Helicopter long C.G.range.
 

Can someone make clear to me the purpose of developing the longitudinal C.G. range in helicopters? I'm curious to know if it's more than just being able to control the helicopter (running out of fore and aft cyclic travel). Are stability, and/or stress on main rotor mast bearings factors which also help establish the range? It's a topic that comes up often, and I figured I'd ask the experts. Thank you.

There are a whole host of things that can dictate the CG range, and you hit on a lot of them. Bending moments in the head are a large one for most modern helicopters - mostly fatigue loads at high speed get quite high as some of the extremes. And for some machines, notably teetering rotor head machines, running out of cyclic is a problem as well.