Executive summary
On Sunday 30 November 2003 at about 1015, ZK-HCC, a Hughes 369HS helicopter, was on a scenic flight near the head of Fox Glacier at about 9500 feet when its engine power turbine and main rotor speed suddenly reduced. On board were 4 passengers and the pilot.
The pilot descended the helicopter to 6500 feet where power was restored. Several minutes later a second power loss occurred so he carried out an emergency landing at the base of Fox Glacier. The right rear skid broke when it struck a large rock during the landing, and the helicopter consequently rolled onto its right side. No one was seriously injured in the accident.
A power turbine governor underspeed condition resulted when electrical continuity to the governor switch on the collective lever was lost, thus reducing the power turbine speed to its minimum setting
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Safety issues identified were the need to ensure that governor switches were securely fastened to the collective lever, and to refresh pilots’ knowledge about power turbine governor underspeeds. Safety recommendations were made to the Director of Civil Aviation addressing these issues.
Related Recommendations
After the Commission publishes its final report, use this accident scenario in CAA educational material to refresh helicopter pilots, instructors and examiners knowledge about PTG underspeeds.
Advise all Hughes 369 operators to ensure that N2 governor (beep) switches, and other toggle switches, are securely fastened to prevent any abnormal movement.