shade tree engine mount repair

[AV8R_87]

Putting legality (or lack of it) aside for a moment, I see no buckling in those tube halves, and no elongation in the mounting holes.
I wonder if whoever did the repair actually understood how the loads were distributed in the mount (lack of buckling would make me think the main load through that tube was in tension, not compression) and that bodge held together through a lot more than sheer (shear??) luck.

 

[Dan Thomas]

Putting legality (or lack of it) aside for a moment, I see no buckling in those tube halves, and no elongation in the mounting holes.
I wonder if whoever did the repair actually understood how the loads were distributed in the mount (lack of buckling would make me think the main load through that tube was in tension, not compression) and that bodge held together through a lot more than sheer (shear??) luck.

An engine mount is designed to take 9G vertically and forward/aft, if I remember right. 3G sideways. Now, a bolt through that tubing cannot carry nearly the load as a tube in good condition. The wall of that tubing is typically only about .035" thick; that's the thickness of ten sheets of printer paper. A bolt through that will soon rip out of the tubing when the mount experiences severe loading that is still well within its design limits. Get into some rough air, or crash into the trees, and the engine comes off and who knows where it goes? Into the cabin, with its prop whirling, maybe. In any case, things get ugly.