Originally Posted by
Heliice
Outwest : because a rotor head/gearbox/airframe suspended by only two out of three suspension bars has negative dynamic stability.
Not sure what negative dynamic stability is.... But jimf said "balance" and I agree that the forces generated by an out of BALANCE are extreme such as losing a blade.
I have a good friend who lost about 6 feet of an S61 blade and although the result was not pretty, they all survived and the MGB/rotor head stayed attached.
I will eat crow if it is proven that the failure of one suspension bar/pin caused this, but until then I just can't believe that was the cause.