I think that would also work. Anything that absorbs the energy of the tail, and provides a decent amount of "cushion" to absorb it instead of merely instantly transferring it someplace else, is good. The reason I didn't use purely a spring is because of the rebound tendency. I'm afraid that the rebound of a big spring might bounce the tail and rotor back to partially furled and cause erratic operation.
The key, to my way of thinking on it, is to make it so the operation of the furling system is smooth. If the wind catches the tail when it's in a partially furled condition, and slams it up against the stop in the full flying position, I think you want it sort of like dropping a bowling ball in the sand box, as opposed to having it spring back, to keep the stresses on stuff down to reasonable limits.
The best furling system I ever developed is the spring loaded vertical hinge type used on my 12G turbines. Those are so silk smooth that it just doesn't get any better. That's because it's dampened both ways and the furling rate is constant to 70% furled, instead of progressive, and drops off as the linkage approaches over-center. This brings the rotor back into the wind very gently and very smooth instead of a radical return like an angled hinge system has. I've only recently gone back to the old angled hinge system because the linkages on the type used on the 12G won't fit around the large ferrite generators I'm using now.
I've been working on different furling systems for the better part of three years. Ultimately, I'm looking at methods to eliminate it all together because turn-it-to-the-side furling is not exceedingly reliable no matter what you do. It's pretty much stupid to impose huge gyroscopic forces and torque loads on the turbine head structure in high winds when there are better, and proven, methods to control power output that don't require swinging the rotor around the yaw axis.
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Chris