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Air transportation safety investigation A21C0038

The TSB has completed this investigation. The report was published on 15 February 2024.

Table of contents

Collision with terrain

Great Slave Helicopters 2018 Ltd.
Airbus Helicopters AS 350 B2 (helicopter), C-FYDA
Griffith Island, Nunavut

View final report

The occurrence

At approximately 1548 Central Daylight Time on 25 April 2021, the Great Slave Helicopters 2018 Ltd. Airbus Helicopters AS 350 B2 (registration C-FYDA, serial number 4157) departed from a remote camp on Russell Island, Nunavut, on a day visual flight rules (VFR) flight to Resolute Bay Airport, Nunavut, located 87 nautical miles to the northeast. On board were the pilot, an aircraft maintenance engineer, and a biologist. The purpose of the flight was to return to Resolute Bay following 12 days spent conducting polar bear research for a client, given that poor weather was forecast in the area for the next several days.

At approximately 1633 Central Daylight Time, the helicopter impacted the snow-covered terrain on Griffith Island, Nunavut, approximately 12 nautical miles southwest of Resolute Bay Airport, on a near-reciprocal track to the intended route. The helicopter was destroyed, and a post-impact fire consumed much of the fuselage area. The emergency locator transmitter was destroyed during the impact sequence and did not transmit a distress signal. There were no survivors.

In addition to the circumstances that most likely led to the collision with terrain resulting from a loss of visual references in flat light and whiteout conditions, the investigation examined the factors that likely influenced the pilot’s decision-making process, the organizational defences in place at Great Slave Helicopters 2018 Ltd., and the regulatory environment.

Pilot decision making

The investigation found that the Transport Canada Aeronautical Information Manual provides very little guidance to operators and pilots with regards to strategies to recognize and cope with flat light and whiteout conditions. As a result, pilots may lack vital information to avoid or deal with inadvertent flight into instrument meteorological conditions (IIMC), increasing the risk of collision with terrain. In this occurrence, the pilot’s limited experience operating above the tree line during the winter and spring months likely lowered his perception of risk, influencing the decision to continue flight over featureless snow-covered terrain under overcast skies and poor visibility, conditions that were conducive to flat light and whiteout.

Furthermore, when engaged in remote operations, it is important for companies to implement measures to ensure an adequate level of supervision and to ensure that resources are in place to support pilot decision making. On the day of the occurrence, the pilot likely placed considerable weight on the client’s assessment that the weather was suitable for the return flight to Resolute Bay Airport, leading him to believe that additional weather information and/or a formal weather briefing from a source like NAV CANADA was not needed. As a result, safety margins were inadvertently reduced. If operators informally defer to, or encourage pilots to rely on, clients for flight-following activities, there is an increased risk that pilots will not receive sufficient supervision and decision-making support, such as relaying of weather information.

Defences against inadvertent flight into instrument meteorological conditions

The investigation determined that when the helicopter, which was being operated under day VFR, approached the highest elevation on Griffith Island, the uniformly snow-covered and featureless terrain, an overcast sky, and snow squalls likely created flat light and whiteout conditions that resulted in instrument meteorological conditions. Then, while the pilot was likely attempting to visually manoeuvre the helicopter in response to IIMC, an unintentional descent resulted in the helicopter impacting the terrain on a near-reciprocal track to the intended route.


In order to make optimal decisions, pilots rely on their experience and training to build situational awareness by actively seeking out relevant cues, understanding those cues, and anticipating how those cues could affect the flight. However, in this occurrence, the pilot’s decision to depart was based on an incomplete understanding of the weather forecasted along the intended route. As a result, it is likely that his inaccurate mental model diminished the perceived importance of contingency planning for adverse weather.

The current regulations for day VFR helicopter operations focus primarily on defences designed to avoid IIMC. As such, there was no requirement for the occurrence pilot to be trained to recover from an IIMC encounter.

Because there is no requirement for commercial helicopter operators to ensure that pilots possess the skills necessary to recover from IIMC, the pilots and passengers who travel on VFR helicopters are at increased risk of collision with terrain following a loss of visual references.

The TSB has previously called for requirements for verification of proficiency in basic instrument flying skills for commercial helicopter pilots during annual pilot proficiency flight checks. However, Transport Canada (TC) has yet to implement sufficient measures in this regard. Therefore, the Board recommends that

the Department of Transport require commercial helicopter operators to ensure pilots possess the skills necessary to recover from inadvertent flight into instrument meteorological conditions.
TSB Recommendation A24-01


Not only do the current regulations for day VFR helicopter operations not require pilots to be trained for IIMC recovery, they also do not require that aircraft used for these operations be equipped with technology that can assist with the avoidance of, and recovery from, IIMC. One of the most basic examples of this technology is flight instrumentation. In addition, several technological advances have emerged that can enhance pilot situational awareness and, therefore, assist in the reduction of IIMC accidents.

The TSB has previously attempted to address safety issues related to helicopter collision with terrain accidents, calling for increased requirements for flight instrumentation and other systems such as radar altimeters. To date, TC has not taken the measures needed to address these recommendations, which were issued more than 30 years ago. Therefore, the Board recommends that

the Department of Transport require commercial helicopter operators to implement technology that will assist pilots with the avoidance of, and recovery from, inadvertent flight into instrument meteorological conditions.
TSB Recommendation A24-02

Regulatory environment

Standard operating procedures

The investigation found that Great Slave Helicopters 2018 Ltd. adopted an approach consistent with the current regulations that relies on a pilot’s ability to avoid IIMC. As a result, the occurrence pilot lacked the skills to recover from IIMC. Standard operating procedures (SOPs) are widely accepted as a tool to enhance safety in multi-crew operations, and many of those same benefits apply equally to single-pilot operations. SOPs are particularly beneficial when a pilot lacks the knowledge or experience in a situation where a less-than-ideal course of action could reduce safety margins. However, single-pilot operations conducted under subparts 604, 702, 703, and 704 of the Canadian Aviation Regulations (CARs) are permitted without SOPs.

If SOPs for single-pilot operations are not required for CARs subparts 604, 702, 703, and 704 operators, those pilots may not be provided with vital decision-making support, increasing their potential to operate with levels of risk higher than necessary. Pilots and passengers who travel on those aircraft are consequently at increased risk of accident resulting from ineffective decision making and from cognitive workload in response to novel or unexpected situations. Therefore, the Board recommends that

the Department of Transport require operators conducting single-pilot operations under Subpart 604 and Part VII of the Canadian Aviation Regulations to develop standard operating procedures based on corporate knowledge and industry best practices to support pilot decision making.
TSB Recommendation A24-03

Helicopter requirements for reduced-visibility operations in uncontrolled airspace

Moreover, many VFR helicopter and airplane operators are approved by TC to conduct reduced-visibility operations in uncontrolled airspace. The approval, granted as an operations specification, outlines requirements that operators must meet to carry out reduced-visibility operations in uncontrolled airspace. Some of these requirements are the same for helicopters and airplanes; however, the requirements for visibility limits, aircraft equipment, and pilot training are less strict for helicopters than for airplanes. This is despite the fact that the TSB has determined that helicopter accidents are more than twice as likely to involve a loss of visual reference than are airplane accidents.

If regulations continue to allow commercial helicopter operators with the applicable operations specification to conduct reduced-visibility operations in uncontrolled airspace at lower visibility, and with significantly fewer defences, than commercial airplane operators, these helicopter operators will continue to be at a greater risk of collision with terrain as a result of loss of visual references. Therefore, the Board recommends that

the Department of Transport enhance the requirements for helicopter operators that conduct reduced-visibility operations in uncontrolled airspace to ensure that pilots have an acceptable level of protection against inadvertent flight into instrument meteorological conditions accidents.
TSB Recommendation A24-04

Safety management

Although not required by regulation, Great Slave Helicopters 2018 Ltd. implemented a system to manage safety—similar to a safety management system (SMS). An SMS allows companies to proactively manage safety through the timely identification of hazards that can reduce safety margins, and the implementation of defences to reduce those risks. The investigation determined that the risk management process at Great Slave Helicopters 2018 Ltd. overestimated the occurrence pilot’s level of operational readiness and the ability of existing defences to mitigate the risk posed by flat light and whiteout conditions. As a result, the occurrence pilot was dispatched to conduct remote operations, above the tree line, with insufficient safeguards to ensure adequate safety margins were maintained. If Transport Canada does not require all Canadian Aviation Regulations Part VII operators to have an SMS and does not evaluate these systems for effectiveness, there is a risk that operators will rely on inadequate processes to manage safety.

Safety action taken

Following the accident, Great Slave Helicopters 2018 Ltd. took several safety actions. These include a company-wide safety stand-down to ensure all personnel were safe to continue work; amendments to the SOPs following discussions with pilots about operating “in the white;” enhanced training and revised reference material related to overdue aircraft procedures; increased pilot recurrent training, with an emphasis placed on pilot decision making; several changes to its system for managing safety; the implementation of quarterly safety management meetings; and the creation a sub-committee that involves pilots and aircraft maintenance engineers in the review process of reports from its system used to manage safety.

Media materials

News release


TSB raising the bar on safety: Reducing the risks that persist in commercial helicopter operations
Read the news release

Speeches and presentations


Media advisory


TSB to issue four recommendations following investigation into the 2021 fatal helicopter accident in Nunavut
Read the media advisory


Deployment notice


TSB deploys a team following a fatal helicopter accident near Resolute Bay, Nunavut

Richmond Hill, Ontario, 29 April 2021 — The Transportation Safety Board of Canada (TSB) is deploying a team of investigators following a fatal accident involving an Airbus Helicopter AS 350 B2 that occurred on 25 April, near Resolute Bay, Nunavut. The TSB will gather information and assess the occurrence.

Investigation information

Map showing the location of the occurrence


Photo of Daryl Collins

Daryl Collins joined the TSB in 2009 after a 20 year career with the Canadian Armed Forces, having flown as a search and rescue helicopter pilot on the CH146 Griffon, the CH113 Labrador, and the CH149 Cormorant helicopter. In his last position with the Canadian Forces, Mr. Collins was the Commanding Officer of 103 Search and Rescue Squadron based out of Gander, Newfoundland and Labrador.

During his time with the Canadian Forces, Mr. Collins was responsible for the development and implementation of Canadian Forces-wide human performance training for all aircrew, maintenance, and air traffic control personnel and was heavily involved in flight safety. In addition, he obtained a Masters of Aeronautical Science with a dual specialization in Human Factors and System Safety.

Since joining the TSB, Mr. Collins has been actively involved in numerous accident investigations.

Mr. Collins holds an Airline Transport Licence – Helicopter with over 3200 hours of flying experience.


Class of investigation

This is a class 2 investigation. These investigations are complex and involve several safety issues requiring in-depth analysis. Class 2 investigations, which frequently result in recommendations, are generally completed within 600 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.