Undetected descent led to a 2021 helicopter accident in Wachigabau Lake, Quebec
Dorval, Quebec, 31 August 2023 — Today, the Transportation Safety Board of Canada (TSB) released its investigation report (A21Q0097) into the 2021 helicopter accident near Waswanipi, Quebec.
On the morning of 8 October 2021, a Synergy Aviation Ltd. Guimbal Cabri G2 helicopter departed from a staging area in Chapais, Quebec, to conduct airborne geophysical survey work in the area. While operating at low altitude over Wachigabau Lake, the helicopter struck the surface of the lake, overturned, and began to sink. The pilot, the sole occupant on board, sustained serious injuries from the impact, but was able to egress from the helicopter and swim to shore.
The investigation revealed that Synergy Aviation pilotsincluding the one in this occurrence, were verbally instructed to fly as low as safely possible and within their own personal comfort limits, to obtain good-quality data for their clients. If helicopters are operating at low levels in areas where there are insufficient visual cues to accurately determine height above ground, and additional equipment is not installed or used to help determine the helicopter’s height, there is an increased risk that an inadvertent descent will result in a collision with terrain.
The investigation also found that the routine practice of descending and flying below 25 metres when over water or flat, open fields, left the occurrence pilot with insufficient height and time to detect and react to operational hazards. Additionally, while flying at a low level over the lake, the mirror effect of the glassy water resulted in a reduction of visual cues needed for depth perception. Consequently, an inadvertent descent went unnoticed by the pilot and the helicopter collided with the surface of the lake.
Following the occurrence, a safety management system investigation and report were completed, a series of corrective actions were identified, and the company continues to monitor their implementation.
Safety management has been on the TSB’s Watchlist since 2010. As this occurrence demonstrates, SMSs that are implemented voluntarily by operators are not subject to Transport Canada’s regulatory oversight, and may not be effective at identifying aviation hazards and managing their risks.
See the investigation page for more information.
The TSB is an independent agency that investigates air, marine, pipeline, and rail transportation occurrences. Its sole aim is the advancement of transportation safety. It is not the function of the Board to assign fault or determine civil or criminal liability.
For more information, contact:
Transportation Safety Board of Canada