Doug
Well Known Member
This is a very helpful thread, inspection prior to my next flight..
I may be stateing the obvious but it seems to me that if one of the bearings is screwed out relative the the hinge line (ie a miss-aligned hinge as per the discussion), then this would result in a force on the elevator or rudder spar that in trail would be normal to the spar, but would vary in direction according to the control surface deflection. So moving the surface from full up to full down would correspond to one cycle of such a force. The least stiff part will 'give', this is probably the spar at exactly the point the cracking has occurred. It would be a large misalignment to be felt as binding.
I would expect cracking on the opposite side of the bearing as well if the bearings were misaligned only in the sense of one being screwed out beyond the hinge line.
Is there any evidence of the .063" doubler cracking?
What I am most concerned with would be the rudder bearing alignment. The lower bearing is tied to the fuselage and Tailwheel assembly and the lower part of the VS spar can be pulled out of alignment when mounted on the fuse. Also, any pressure on the VS forward spar when attached will also pull this alignment out. So it is mandatory to carefully realign these bearings after VS final attachment.
I may be stateing the obvious but it seems to me that if one of the bearings is screwed out relative the the hinge line (ie a miss-aligned hinge as per the discussion), then this would result in a force on the elevator or rudder spar that in trail would be normal to the spar, but would vary in direction according to the control surface deflection. So moving the surface from full up to full down would correspond to one cycle of such a force. The least stiff part will 'give', this is probably the spar at exactly the point the cracking has occurred. It would be a large misalignment to be felt as binding.
I would expect cracking on the opposite side of the bearing as well if the bearings were misaligned only in the sense of one being screwed out beyond the hinge line.
Is there any evidence of the .063" doubler cracking?
What I am most concerned with would be the rudder bearing alignment. The lower bearing is tied to the fuselage and Tailwheel assembly and the lower part of the VS spar can be pulled out of alignment when mounted on the fuse. Also, any pressure on the VS forward spar when attached will also pull this alignment out. So it is mandatory to carefully realign these bearings after VS final attachment.
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