Loss of an engine

[JAG]

This is not the first time on this forum we have heard of nuts coming off the accessory case on the rear engine. All these are hard to get at spots - so it is important to use NEW lock washers or NEW locknuts when installing mags, Alternators, etc.

Not so much on piston engines, but high frequency vibrations can also back nuts off the studs. I suspect though in your case Tom, it may have been worn out or improper hardware.