Date: 13 July 2006
Location: Chedabucto Bay, near Canso, Nova Scotia

From the Investigator (FTI) (pdf 113 kb)
Flight Safety Investigation Report (FSIR) (pdf 3,350 kb) Posted 2008-03-11
Epilogue (EPI) (pdf 85 kb) Posted 2008-03-11

Epilogue:

The accident involved a CH149 Cormorant Search and Rescue (SAR) helicopter with a crew of seven that was on a training mission to practice night boat hoists from the fishing vessel Four Sisters No.1. The cockpit crew consisted of a First Officer (FO) in the left pilot seat, an FO acting as Aircraft Captain (AAC) in the right pilot seat and the actual Aircraft Captain (AC), seated in the cockpit jump seat. The crew in the cabin area comprised a Flight Engineer (FE), a Flight Engineer under training (FEUT), a SAR Tech Team Lead (SAR Tech TL) and a SAR Tech Team Member (SAR Tech TM).

The accident occurred during an attempted go-around from an approach to a fishing vessel. During the go-around the helicopter entered a nose-low attitude and seconds later the aircraft impacted the water with 69 knots forward speed in an 18 degree nose-down attitude. The three pilots and the SAR Tech TL were injured but survived the crash. The two flight engineers and the SAR Tech TM were unable to egress the aircraft and did not survive. The aircraft sustained damage beyond economical repair.

No evidence was found that any system malfunction contributed to the accident, so the investigation focused on the environment, organizational and human factors. The investigation found that the flying pilot's trim technique caused the flight control pitch actuators to become saturated, which in turn caused the loss of the helicopter's automatic stabilization system. In this condition, the helicopter's inherent instability combined with the pilot's inputs to create a large but unrecognized nose down attitude and descending flight path.

The environmental conditions (darkness, distant dim horizon and calm water) were not suitable for continued flight using outside references only. The nose down attitude and descent was not noticed by any of the three pilots in the low visual cueing environment because they did not adequately reference their flight instruments.

The investigation also found that prolonged training restrictions imposed due to on-going tail-rotor half-hub cracking had a serious detrimental effect on overall CH149 aircrew proficiency, particulary at 413(TR) Squadron. The resultant risk to operational airworthiness was underestimated and not effectively mitigated.

Although the four cabin area crew members survived the impact, only one was able to successfully egress the aircraft before his air supply was exhausted. Survivability issues included cabin layout, storage of equipment, and the suitability of the Aircraft Life Support Equipment. Activity is underway to rectify many of the safety deficiencies identified through the course of the investigation. The Flight Safety Investigation Report contains many recommendations to improve CH149 pilot proficiency, training and survivability / life support equipment issues for CH149 aircrew.