HokiePilot said:With a semi-rigid head, think of the fuselage as simply hanging beneath the center of the rotor. Flying around in 1g this is no problem because the rotor just pulls the fuselage around. When you get to 0g's, the attitude of the helo and rotor are no longer coupled. The fuselage will experience a right rolling tendency because of the tail rotor. A natural pilot reaction of left cyclic to counter the roll will cause the rotor to roll until the droop stops start hitting the mast. Two important pieces of metal hitting each other hard many times a second = BAD. (Rotor flies off, Rotor starts to cut fuselage into pieces, etc.)
At this point in the conversation, I stop and thank God that my plane is smarter than me and won't let me hurt her.