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Air transportation safety investigation A18W0025

The TSB has completed this investigation. The report was published on 04 September 2018.

Table of contents

Collision with terrain

Sahtu Helicopters Ltd.
Airbus Helicopters AS 350 B2, C-FWCR
Tulita, Northwest Territories, 3 nm WNW

View final report

The occurrence

On , an Aerospatiale AS-350-B2 aircraft operated by Sahtu Helicopters was conducting an engine warm-up run on a hilltop helipad approximately three nautical miles west-north-west of Tulita, Northwest Territories.

After the engine was started and brought up to 70% gas generator speed (Ng), the helicopter began to vibrate, started to bounce and yaw to the left. In response, the pilot increased the Ng and just before it stabilized at 100%, he raised the collective to lift the helicopter off the helipad.

The main rotor speed, which was outside the governing range, decreased, and the pilot could not maintain control. The helicopter contacted the ground, tumbling approximately 140 feet down the mountain. The pilot, who was the sole occupant, was seriously injured. He was wearing the lap and shoulder harness, but no helmet. The emergency locator transmitter (ELT) did not activate.

Media materials

News release


Investigation report: February 2018 collision with terrain near Tulita, Northwest Territories
Read the news release

Investigation information

Map showing the location of the occurrence


Photo of Mike Adam

Mike Adam joined the Transportation Safety Board of Canada (TSB) in early 2014, bringing with him extensive experience in aviation line maintenance and quality assurance for transport category air carriers. Mr. Adam also has experience with various single and twin engine aircraft, both piston and turbine powered, as well as amateur-built aircraft.

  Download high-resolution photos from the TSB Flickr page.

Class of investigation

This is a class 4 investigation. These investigations are limited in scope, and while the final reports may contain limited analysis, they do not contain findings or recommendations. Class 4 investigations are generally completed within 220 days. For more information, see the Policy on Occurrence Classification.

TSB investigation process

There are 3 phases to a TSB investigation

  1. Field phase: a team of investigators examines the occurrence site and wreckage, interviews witnesses and collects pertinent information.
  2. 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.
  3. 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.