Occurrence
On 8 October 2021, at 1030 Eastern Daylight Time (EDT), a Synergy Aviation Ltd. Guimbal Cabri G2 helicopter (registration C-GSYN, serial number 1176) departed from a staging area in Chapais, Quebec, 12 nautical miles west of the Chibougamau/Chapais Airport (CYMT), Quebec. The pilot was the sole occupant on board the aircraft, which headed southwest toward Wachigabau Lake, Quebec, to perform airborne geophysical survey work.
Accident
At approximately 1144 EDT, as the helicopter was operating at low altitude over Wachigabau Lake, it struck the surface of the lake, overturned, and started to sink. The pilot sustained serious injuries from the impact, but conducted an underwater egress and swam to shore. No emergency locator transmitter distress beacon signal was captured by the Cospas-Sarsat system.
Rescue
At 1402 EDT, the Synergy Aviation Ltd. Operations manager called the Joint Rescue Coordination Centre in Trenton, Ontario, to report the accident. The pilot was rescued by a Canadian Armed Forces helicopter at 1641 EDT and taken to the Chibougamau Hospital.
Investigation
This occurrence was investigated as a class 3 investigation, which analyzes a small number of safety issues and may result in recommendations. The investigation determined that an undetected descent led to the accident.