Auto Rotation and Smooth Bladesw
I used to play bridge with Frank Erickson Brantley's original test pilot. Frank said, "he never had any problem at all with auto rotations, but he had so may hours flying the B2 chained to the ground on a very short leash he really knew how it felt when it ran out gas close to the ground. To overcome the problem less experienced pilots had getting into auto-rotation 3 5 pound steel weights were added to the tip of each blade.
Ir takes an experienced mechanic 20 to 40 hours to get those 3 blades running smooth the first time. Each blade can be moved forward and back to adjust how it tracks the other blades. There is also a hole in the end of each of leading edge blade spar that Woods Metal can be put in or removed from to get the final blade balance. Getting the steel screws out of an old spar to rebuild the blade take an EDM machine as the steel screw in almost every one has seized to the aluminum treads in the spar.
Gordon
An old machinist for N. O. Brantley and Mike Hynes.