The Transportation Safety Board of Canada (TSB) has released its investigative report regarding the controlled flight into terrain by a de Havilland DHC-6 Twin Otter aircraft, operated by Air Tindi Ltd., at Lac de Gras, Northwest Territories, on December 27, 2023
The aircraft departed Margaret Lake under visual flight rules (meaning the weather is clear enough for the pilot to navigate visually), carrying 2 crew members and 8 passengers. Upon approaching their destination, the crew were unable to visually determine their position due to poor weather and attempted a series of instrument-based approaches. On the 4th of these, the aircraft dipped below 50ft and collided with a hill nearby the designated landing site. Two passengers were seriously injured, while the remaining occupants received minor injuries.
The investigation found that the flight crew continued despite deteriorating weather conditions due to previous successes in similar conditions, leading to a reduced perception of the risks of continuing the flight. It was also found that the flight crew often deviated from proper procedures, and that Air Tindi Ltd.’s oversight mechanisms did not effectively detect or respond to these deviations.
This incident highlights one of the major hurtles in Transport Canada’s oversight of the industry, as documented procedures and actually practices can diverge significantly, making proper regulation difficult. Regulatory surveillance is a TSB Watchlist issue.
Following this incident, Air Tindi Ltd. Conducted in internal safety investigation and found several opportunities to improves its practices and procedures. Some of these measures include increased weather limits, enhanced pilot monitoring requirements and upgraded aircraft instruments.
The full investigation report can be found on the TSB’s website.
