Hughes 369 Safety Record

The flight instructor's failure to verify that the helicopter's skid was clear of an obstruction while demonstrating a one-skid and toe-in landing maneuver. Contributing to the accident was the flight instructor's decision to practice this maneuver at an unauthorized landing site.

The passenger's inadequate visual lookout and failure to maintain clearance from the rotating main rotor disc while the helicopter was hovering. An uphill terrain condition was a factor

The fatigue failure of a turbine blade due to a localized over-temperature of the turbine section as result of a non-uniform fuel distribution by the fuel nozzle. Contributing to the accident was the close proximity of a power line support structure which restricted maneuverability for a successful autorotation.

The pilot's failure to maintain clearance with the transmission wires due to an inadquate visual lookout while maneuvering during a search and rescue flight.

The pilot's continued VFR flight into instrument meteorological conditions, and his failure to maintain terrain clearance. A contributing factor was mountainous terrain.

The pilots continued visual flight rules flight into instrument meteorological conditions resulting in his becoming spatially disoriented and loosing control of the helicopter, which resulted in an uncontrolled descent and impact with the ground.

The improper shimmying of the tail rotor driveshaft by maintenance personnel which induced fatigue in the tail rotor driveshaft coupling causing it to fail, which resulted in a loss of tail rotor control. A factor is the failure of the pilot to recognize the warning vibrations indicating impending failure of the coupling.

The pilot's failure to adequately compensate for the wind condition and failure to maintain a proper rate of descent which resulted in the inadvertent loss of tail rotor effectiveness during a downwind turn.

The unapproved field modification of the cyclic trim switch, including the use of non-standard parts, which resulted in a hard-over lateral trim failure, and the pilot's subsequent failure to maintain control of the helicopter during a landing approach. A factor in the accident was the operator's failure to comply with a factory service bulletin, which required replacement of the switch with a new version, and the pilot's continued operation with a known discrepancy.

erosion of second stage stator vanes, inadequate maintenance inspection for the erosion, and subsequent fatigue failure of a stator vane, which resulted in loss of engine power and a forced landing on mountainous/hilly terrain. Also causal was: the pilot's loading of the aircraft in such a manner that exceeded the forward CG limit, which resulted in his failure (or inability) to properly flare the helicopter during a forced autorotation and landing. The rising terrain and tailwind condition for landing were related factors.