An in-flight separation of the tip block from the tail rotor blade due to an inadequate blade repair, which resulted in a rotor imbalance sufficient to crack the gearbox attachment studs and gearbox support assembly, and inadequate postrepair test procedures, which failed to detect the inadequate adhesive bonding.

The loss of engine power due to the failure of the 3rd stage turbine wheel and subsequent catastrophic failure of the turbine assembly.