CH146437 Griffon - Epilogue

Report / July 5, 2012 / Project number: CH146437-C-Cat

Location: Namao Airport, Edmonton, AB.
Status: Investigation Complete
Date: 05 July 2012

On completion of a Basic Handling and Emergency training flight, Griffon CH146437 was attempting to conduct a descending, decelerating transition to the hover to a spot south of the fuel pumps with a right hand turn to a northerly heading.  During this final turn, the aircraft began to sink rapidly; the First Officer (FO) raised the collective to a position which he believed to correspond with maximum mast torque (QM) but the aircraft continued to descend.  Just after the FO levelled the aircraft, Griffon CH146437 landed hard and sustained C category damage.  The Flight Engineer suffered minor injuries.

The investigation focused on power management, aircrew flying rates, aircrew fault analysis, aircrew factors, crew pairing and mentorship.

The investigation concluded that the crew entered into a settling with power situation from which they did not recover.  An incorrect wind advisory by the Advisory Controller, an inadequate wind appreciation by the crew and the attempt of a descending, decelerating transition to the hover with an inadequate assessment of closure rates were factors in this accident.  A significant contributing factor included poor power management; the blades were not loaded during the final approach, both pilots inaccurately assessed the collective position and they did not increase it to its maximum travel.  Lastly, the aircraft captain (AC) did not recognize the point at which he needed to provide assistance to the FO.  Collective travel, corresponding QM and rotor RPM were available to slow the rate of descent and potentially prevent the accident. 

The investigation team also found that the low yearly flying rate amongst 1 Wing pilots could hamper skill development, delay progress in the pilot upgrade program, and degrade experience levels.  Several ACs within 1 Wing have not received any formal fault analysis and debrief training and may be ill-prepared to mentor and assist junior FOs.  The AC’s expectancy and complacency during the approach and the FO's lack of consistent crew pairing during the early stage of his rotary wing flying career were also safety concerns.

Post-accident safety actions taken by the unit Commanding Officer included amendments to his flight authorization process, the implementation of a unit mentorship program and modifications to local arrival procedures.  Recommendations included addressing the gap in Fault Analysis and Debrief training, developing a Wing mentorship program and ensuring Air Traffic Control (ATC) wind notification procedures are followed as per the ATC Manual of Operations.  Finally, a Record of Airworthiness Risk Management should be created to address the low aircrew experience levels within 1 Wing. 

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