20030721037089A

(-23) The connection of the governor control arm to the airframe collective droop compensation linkage became disconnected, apparently through improper securing of the nut and cotter pin. This break in the continuity of the engine control system seems to have initially allowed the governor arm, once disconnected, to move in the decrease direction. The resulting decrease in N2 caused the nr to droop and the pilot experienced a yaw to the left combined with a low rotor warning. Reduction of the collective by the pilot when entering autorotation further allowed the airframe control rod to move away from the governor arm thus allowing the governor to (a) decrease more and (b) allow this rod to position itself in the area of the governor arm stop ear, located directly below the normal attachment point. Prior to touch down, the pilot pulled full collective and executed an autorotation. Unknown to the pilot at that time was the action on the governor stop ear by the disconnected control rod in the full increase direction. This sudden movement of the aircraft caused by an unexpected increase in N2/NR resulted in an almost instantaneous lift-off of the aircraft after touchdown and subsequent impact with the trees.