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Air transportation safety investigation A21Q0097

The TSB has completed this investigation. The report was published on 31 August 2023.

Table of contents

Controlled flight into terrain

Synergy Aviation Ltd.
Guimbal Cabri G2 (helicopter), C-GSYN
Wachigabau Lake, Quebec

View final report

The occurrence

On , at 1030 Eastern Daylight Time (EDT), Synergy Aviation Ltd. Guimbal Cabri G2 helicopter (registration C-GSYN, serial number 1176) departed from a staging area in Chapais, Quebec, 12 nautical miles west of the Chibougamau/Chapais Airport (CYMT), Quebec. The pilot was the sole occupant on board the aircraft, which headed southwest toward Wachigabau Lake, Quebec, to perform airborne geophysical survey work.

At approximately 1144 EDT, as the helicopter was operating at low altitude over Wachigabau Lake, it struck the surface of the lake, overturned, and started to sink. The pilot sustained serious injuries from the impact, but conducted an underwater egress and swam to shore. No emergency locator transmitter distress beacon signal was captured by the Cospas-Sarsat system. At 1402 EDT, the Synergy Aviation Ltd. Operations manager called the Joint Rescue Coordination Centre in Trenton, Ontario, to report the accident. The pilot was rescued by a Canadian Armed Forces helicopter at 1641 EDT and taken to the Chibougamau Hospital.

Media materials

News release


Undetected descent led to a 2021 helicopter accident in Wachigabau Lake, Quebec
Read the news release

Investigation information

Map showing the location of the occurrence


Photo of Jean-Pierre (Jeep) Régnier

Jean-Pierre (Jeep) Régnier is a senior investigator, Standards and Quality Assurance, with the Air Investigations Branch at the TSB head office in Gatineau. He has over 30 years of aviation experience, including 27 years in military aviation in the Royal Canadian Air Force (RCAF) as an officer and a helicopter pilot. During those 27 years in the RCAF, he worked as an accident investigator for 5 years. Mr. Régnier gained his flight experience on the CH-124 Sea King and Bell 206 Jet Ranger helicopters. He earned a master’s degree in safety and accident investigation from Cranfield University, United Kingdom, and joined the TSB in 2015.


Wachigabau lake, occurrence site

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

  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.