The Huey had a four bolt mounting method....tail boom butted up against the stub on the fuselage and pick your choice of reasons...weak bolts, improper torque of bolts, weak structure, oil canning...bottom line it was just a weak design. The cure was beefing up the structure and requiring closer inspections of the bolts and witness stripes for indications of losss of torque on the bolts.
As time progressed the problem moved on out the tail boom to the 42 degree gearbox mounting and after that was fixed....then it was the 90 degree gearbox mount. Part of those problems were vibrations.....the running joke was in time the bad vibe would get to the end of the tail stinger then we could just saw off the tail stinger and be rid of the vibe.
Memory serves me that Fort Rucker lost two aircraft in one day to tail boom separations.
As it was over Fifty years ago....those are my fuzzy recollections from back then.
Found this while looking for information re tail boom failures on the Huey.
Forestry Logging with surplus Huey's has resulted in a lot of crashes due to mechanical failures with many being tail boom losses.
That has led to a monitoring system of the Tail Boom that has been approved by the US FAA.
https://helihub.com/2016/03/15/faa-a...ection-system/
It was about the time I was in Chinook School so it would have been in mid-to-late '68.
John Dixson would have been at Rucker about that time too I am thinking....perhaps he has a better account.