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In a message dated 6/2/0 10:12:24 PM, you wrote:

<<A thought on the loading of the wing bolts:  These kind of joints work because
the bolt only provides compressive force between the two pieces being attached
(spars in this case).  The bolt must not see any shear itself.>>

Sorry, Ed, but I couldn't disagree more.  The bolts have to be capable of taking ALL the forces in shear.  Some relief may be provided by friction between the clamped items, but I wouldn't design to it.  With respect to your automotive wheel experience, it is easy to see how rotational free play would cause studs to be preferentially loaded (rather than sharing the load) and thus fail.

I should comment that I have no knowledge of the Lancair-IV wings attach geometry.  I just know how the 320/360 goes together.

<<Best bet is to torque to spec., safety wire, and retorque occasionally if
several washers were needed.  Key is that there is adequate thread engagement.>>

I agree with you 100% on this one.  So while we may disagree about how the load is taken, we agree completely on the means to keep them together!

- Rob

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