I have become aware of two separate instances where the mast mounting caps, that hold the mast to the axle, have come loose allowing the mast to tip rearward when elevated. Both instances resulted in fatalities. The mast caps complete the entrapment of the mast mounting around the axle via two bolts/lockwashers.

Has anyone ever heard of mast caps coming loose? Do you believe these are cases where someone simply did not tighten the caps when the mast was installed (or re-installed)?