Anti talk: can you pass on any photos of that head to Shawn, blacmax or me please?
AUS mustering: loads in the outback mustering are generally quite low, more concerned with the cycle records, given the value of S-N curves out at 10^7...
Photo of the descent show apparently that there has been a blade fuselage strike, the upper canopy area is missing, which is consistent with a loss of one blade and the track of the remaining blade. Following fuselage impact, that remaining blade is not going to be hanging around, so may not have hit the tail boom before departing fix.
Coning hinge... the tension on the coning hinge balance to the teetering hinge is important. If the blade starts flapping at the coning hinge instead of the teeter, it imposes very high strains on the blade, and a failure of the blade itself has been recorded in the UK (failed 3/4 through from TE in 20 minutes). Vibration is very high with such failures, no doubt that you are having a fun day. I have had a coning bearing eat itself in 5 minutes, and it was a rapidly decaying condition. I think the mfr would expect this to last longer in general, my event was a 44, and it was 5 minutes. On preflights, look for aluminium oxide (gray dust) around the teeter and coning bold spacer/washers.
Personally, have a query around the +ve delta3 configuration that occurs if the blade flaps at the coning hinge, but some very well respected aerodynamicists consider that not so unusual, gets my attention nonetheless.
RHC is a "finely" designed machine, much stronger than you would expect, and still a great machine to fly. It does get attention with the question of divergence from time to time.
The concord event is probably the most perplexing case out there still on divergence.
Mast bumping is mainly a low g event; at low advance ratios, or hover, you may get a tail boom strike.. but I would be surprised if you get a mast bump straight off with rapid reversal of controls. (don't try this at home... :|
). The mast stops are very good indicators of contact from the inner land of the hub, the preflight of a RHC is worth every second. The rotor system is intolerant of abuse, but is able to still be flown within an impressive envelope with due care to the basic dynamics of a teetering head.
FDR
PS: the report will be very interesting to look at. The general modes of failure are pretty well established and the physical evidence will speak to the specific failure.