Air transportation safety investigation A23P0003
The TSB has completed this investigation. The report was published on 27 June 2024.
Table of contents
Controlled flight into terrain
Summit Helicopters Ltd.
Bell Helicopters Textron Inc. 407 (helicopter), C-GTHU
Terrace, British Columbia, 15 NM NNW
The occurrence
On , the Summit Helicopters Ltd. Bell Helicopters Textron Inc. model 407 helicopter (registration C-GTHU, serial number 53333) was carrying tourists from Terrace Airport (CYXT), British Columbia, to the Northern Escape Mountain Lodge, located approximately 15 nautical miles to the north-northwest. En route, the pilot was informed by lodge personnel that low-level fog had moved into the area surrounding the lodge. The pilot decided to descend and follow the Kitsumkalum River to maintain a visual reference to the ground in an effort to proceed.
As the flight proceeded over Treston Lake and visibility continued to decrease in fog, the pilot flew at less than 100 feet above the lake and slower than 30 knots ground speed. The pilot momentarily lost outside visual reference, and the helicopter contacted the frozen surface of the lake at 1136 Pacific Standard Time. During the contact, the landing skids were significantly damaged but the pilot managed to keep the helicopter flying. The pilot elected to climb above the fog and proceeded to the west toward the lodge. Seeing a break in the fog, the pilot descended and landed at the lodge, where the passengers disembarked.
There were no injuries, and the emergency locator transmitter did not activate.
Media materials
News release
Loss of visual reference led to 2023 controlled flight into terrain at Treston Lake, British Columbia
Read the news release
Investigation information
Map showing the location of the occurrence
Investigator-in-charge
Jeremy Warkentin joined the Transportation Safety Board of Canada (TSB) in 2017 as a Regional Senior Technical Investigator, in the Aviation Investigations Branch, at the regional office in Edmonton, Alberta.
Mr. Warkentin is a graduate of the British Columbia Institute of Technology’s Aircraft Maintenance Engineer (AME) program and has more than 20 years of aviation experience working for several fixed wing operations as a licensed Aircraft Maintenance Engineer, Quality Assurance Manager and Base/Production Manager. He holds both an M1 and M2 license, and has experience on aircraft ranging in size from the Cessna 152 to the Airbus A321.
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.