Hughes 369 Safety Record

an uncontrolled touchdown following entry into a "out-of-ground effect" hover. Factors were loss of tail rotor effectiveness, and the pilot's lack of recent experience in kind of aircraft and total experience in type of aircraft.

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 pilot's failure to refuel the helicopter prior to fuel exhaustion. Factors associated with the accident were an inoperative low fuel warning system, and the pilot's improper autorotation.

The disintegration and failure of the oil pump drive spur gear aft bearing, which resulted in failure of the oil pump and subsequent oil starvation to the engine's turbine module. A factor in the accident was the failure of company maintenance personnel to comply with the manufacturer's service bulletin regarding replacement of the bearing.

The complete loss of power, due to a failure of the compressor impeller disk. Factors include the low altitude of the helicopter at the time of the power loss, and the need to autorotate in a confined area.

The removal of the tail rotor blade abrasion strips by the use of an unapproved method by the maintenance personnel which resulted in the imbalance of the tail rotor blade assembly and subsequent separation of the 90-degree gear box; the pilot/mechanic's unapproved repair to the tail rotor blade tip caps; and, his continued operation of the helicopter with known deficiencies.

A hard landing resulting from rotor rpm decay. Factors were the improper replacement of the turbine by company maintenance personnel resulting in the PC line nut becoming loose, and the pilot operating outside the normal height/velocity curve.

A partial loss of engine power due to erosion in the compressor assembly module. Factors were a missing rotating labyrinth seal, the installation of which had not been performed by unknown maintenance personnel.

Turbine wheel failure as the result of a low-cycle fatigue crack that initiated in a beyond-limits grinding gouge. Factors include improper maintenance by unknown parties and tree stumps that prohibited a successful emergency landing.

The passenger not following the instructions given by the pilot. Contributing factors were the rising terrain and the pilot's diverted attention during the toe in landing.

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.

Uncovering of the fuel tanks outlet, which resulted in fuel starvation and subsequent loss of engine power. A related factor was the unsuitable terrain.