Accident Sequence
The flight departed from the 34th Street Heliport for a local sightseeing tour to the Statue of Liberty and return. While crossing Lower Manhattan, approximately one-quarter mile from the East River, the pilot heard the low rotor RPM audio signal. He lowered the collective, and rotor RPM returned to the green range. As the helicopter turned toward the East River, the generator-out and engine-out warning lights illuminated. The floats were inflated, and the helicopter contacted the water in a level attitude. Subsequently, the nose contacted the water, the chin bubble broke, water entered the helicopter, and it rolled to the right into an inverted position.
Investigation Findings
Examination disclosed that the filter line between the compressor scroll and the power control unit had broken at the filter end. Visual inspection of the failed PC line and the B-nut fitting revealed that the fracture occurred at the outboard end of the ferrule.