Controlled flight into terrain
Air Tindi Ltd.
De Havilland DHC-6 Twin Otter Series 300, C-GMAS
Diavik Aerodrome (CDK2), Northwest Territories, 7NM SE
The occurrence
On , a De Havilland DHC-6 Twin Otter Series 300 aircraft operated by Air Tindi Ltd. was conducting a flight from Margaret Lake, Northwest Territories, to Lac de Gras, Northwest Territories with 2 crew members and 8 passengers on board. On approach to Lac de Gras, the aircraft collided with terrain. Two people sustained serious injuries, and the aircraft was significantly damaged.
Search and rescue technicians from National Defence parachuted into the area to provide medical and survival support overnight. In addition, a volunteer search party from Diavik mine was deployed and arrived on scene the evening of the accident. National Defence personnel, the occurrence crew, and the passengers were flown out to Diavik Aerodrome (CDK2), Northwest Territories, and subsequently to Yellowknife Airport (CYZF), Northwest Territories the following day and received appropriate medical attention. The TSB is investigating.
Media materials
Deployment notice
TSB to investigate an aircraft accident near Diavik, Northwest Territories
Edmonton, Alberta, 28 December 2023 — The Transportation Safety Board of Canada (TSB) will be deploying a team to investigate a collision with terrain involving a Viking Air DHC-6-300 Twin Otter aircraft that occurred Wednesday near Diavik, 300 km north east of Yellowknife, Northwest Territories.
Investigation information
A23W0158
Controlled flight into terrain
Air Tindi Ltd.
De Havilland DHC-6 Twin Otter Series 300, C-GMAS
Diavik Aerodrome (CDK2), Northwest Territories, 7NM SE
Download high-resolution photos from the TSB Flickr page.
Class of investigation
This is a class 3 investigation. These investigations analyze a small number of safety issues, and may result in recommendations. Class 3 investigations are generally completed within 450 days. For more information, see the Policy on Occurrence Classification.
TSB investigation process
There are 3 phases to a TSB investigation
- Field phase: a team of investigators examines the occurrence site and wreckage, interviews witnesses and collects pertinent information.
- Examination and analysis phase: the TSB reviews pertinent records, tests components of the wreckage in the lab, determines the sequence of events and identifies safety deficiencies. When safety deficiencies are suspected or confirmed, the TSB advises the appropriate authority without waiting until publication of the final report.
- Report phase: a confidential draft report is approved by the Board and sent to persons and corporations who are directly concerned by the report. They then have the opportunity to dispute or correct information they believe to be incorrect. The Board considers all representations before approving the final report, which is subsequently released to the public.
For more information, see our Investigation process page.
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.