A point was raised, whether having an extra 1/4 inch material around the bolts which hold the struts to the wing, would help compensate the strength deficit in the material of the strut bracket.
My feeling is that this joint is held secure as long as the bolt-hole in the strut bracket remains intact and holds the bolt snug. Any deformation or elongation of the hole is indication of the beginning of a failure. If the hole has elongated, even very slightly, additional stress is caused by impact loads caused by buffeting of the wings. This buffeting will be barely perceptible, and certainly not large enough to visually draw attention. And further elongation of the bolt hole happens in geometric progression. So irrespective of the amount of safety material you keep around the hole, the impact loads will quickly gorge through all the safety margin. And since the load factor increases in geometric proportion, adding safety material will in fact yield diminishing returns.
I think of it like trying to hammer a nail into the wall in a tight space, where you have no place to move the hammer backwards away from the nail. Since impact load is zero you will not be able to drive the nail into the wall. This should be the state in which the strut bolt is held.
Even for those hangared Mini-Maxes, whose wings are not removed often, it may be a good idea to periodically remove the strut attaching bolts, inspect the strut brackets and bolt holes for wear. This should help detect failures early enough. I would probably inspect the strut attaching brackets after the first flight, then again after the initial flight test phase which may last a few hours, and thereafter every 100 hours or thereabout. |
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