Of course these thrust loads pale into insignificance compared to what 
happens when you drop it in from ten feet. Early P&W R4360 corncob powered
Corsairs had their engines fall off the first time they tried
landing them on a carrier.

Assume both front mounts share 300 pounds between them and the rear 
mount 50 pounds. Then the downloads go up to 900 pounds each side and 300 
pounds on the rear with a 6G impact. Since everything is sized for 
these loads I figure the mount is pretty conservative over all.

Some have questioned the use of the cantilevered bolts in single shear
but they only take thrust loads. 200 pounds  thrust 3/4 inch up 
on the spacer is only 266 inch pounds bending on a steel spacer 
that is about 3/4 inch in diameter. A walk in the park for the 
spacer and the 1/2 inch bolt clamping it to the tripod.

BTW the ratio of vertical stiffness to lateral stiffness of
these Barry rubber mounts can be changed by increasing the 
mounting hole diameter and shimming it with a short piece 
of rubber hose. Not all bad for rubber mounts that cost $6 each
compared to aircraft mounts between $60 and $300 each.

Paul Lamar
 
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