PPRuNe Forums - View Single Post - Helicopter down outside Leicester City Football Club
Old 11th Nov 2018, 08:37
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HarryMann
 
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Originally Posted by MurphyWasRight
From the picture it seems improbable that both locking means were missing/misinstalled.
There is a more subtle issue of the effects of the washer (140) either missing or on the wrong side. This would not jump out on a visual inspection like missing locking means would.

Not discernible from the drawing but appears that the shoulder the washer sits on is probably just a bit larger than the hole in the hinge bracket (90). Lack of washer would allow the system to operate normally but might cause high stress on the hinge bracket leading to a fracture. Even without a fracture it could dig a hole in the hinge bracket resulting in play that could cause other issues such as the nut being loose which in turn could cause other damage.
MWR ... If you are in any way correct, this implies a really poor original design... a prime goal in mechanical components design just as important as stessing and robustness is clarity of assembly whilst minimising potential for mis-assembly...
e.g. all bolts in a locality doing much the same job being of the same length, usually arranged by say stepping a casting thickness .. EVEN IF IT COSTS WEIGHT..
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