CH12424 Sea King - Epilogue

Report / December 2, 2014 / Project number: CH124424 - E Category

Location: CYA 102, South of Victoria, British Columbia
Date: 2014-12-02
Status: Investigation Complete

During an over water CH124 Sea King pilot conversion flight south of Vancouver Island, the crew, consisting of a maritime helicopter flight instructor, a student pilot, an air combat systems officer, and an airborne electronic systems operator, carried out various tactical manoeuvres in accordance with the maritime helicopter co-pilot training plan. During a freestream manoeuvre where the helicopter must initially climb vertically from the over water hover to several hundred feet, the helicopter began drifting rearward and down. The maritime helicopter flight instructor took control from the student pilot and attempted to stop the descent by applying power and adopting a nose down attitude but was not able to fully arrest the descent. This resulted in the helicopter unexpectedly touching down on the water. The maritime helicopter flight instructor then lifted off from the water and returned to Victoria International Airport.

Post-occurrence maintenance inspections and instrument panel video monitoring system revealed no technical faults. The investigation focussed on aircrew actions and human factors. The investigation explored the conditions required for settling with power, vortex ring state, and procedures for conducting freestream manoeuvres.

The investigation concluded that the crew did not recognize the onset of vortex ring state and did not completely carry out a vortex ring state recovery procedure.  This was likely due to the lack of maritime helicopter vortex ring state training.

Recommended preventative measures include evaluating Maritime Helicopter vortex ring state recovery procedures, adding vortex ring state ground and simulator training to the 406 (Maritime) Operational Training Squadron maritime conversion course, and a review of the 406 (Maritime) Operational Training Squadron student pilot flight currency policy.

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