Originally Posted by
ShyTorque
I think it's likely that as the right hand duplex bearing began to seize, the nut on the left side came under a loosening torque but was initially held firm by the resistance of the split pin, as per the design intention and it began to rotate clockwise in the pin carrier. No doubt the locking wire would break at this point. The continued rotation of the shaft simultaneously caused a tightening torque on the starboard nut. When the starboard nut could be tightened no more, the port nut, still rapidly rotating as it was not designed to do, friction welded to the carrier, the split pin then came under sufficient torque to be sheared off, allowing the nut to instantly be unwound off the thread on the end of its shaft, at which point the controls no longer responded to the pilot's input.
ShyTorque, thanks for your explanation and that's how I initially read the report as well. However if you pick up a bolt and a couple of nuts it would seem that in order to loosen the bolt which came off the torque you need to apply via the inside race of a bearing would tend to loosen the nut holding that bearing on also. I am lost as to how this can happen the other way around. Do the actual directions make sense to you? If so I must be misunderstanding the way it is assembled.