Findings from TSB investigation A21C0038: April 2021 collision with terrain on Griffith Island, Nunavut

Investigations conducted by the Transportation Safety Board of Canada (TSB) are complex since an accident rarely results from a single cause. In the case of the 2021 fatal collision with terrain of an Airbus Helicopters AS350 helicopter on Griffith Island, Nunavut (A21C0038), several factors led to the accident. The seven findings below detail the causes and contributing factors that led to this occurrence. Additionally during the course of the investigation, the TSB also made six findings as to risk.

Findings as to causes and contributing factors

These are conditions, acts or safety deficiencies that were found to have caused or contributed to this occurrence.

1. Great Slave Helicopters’ management process 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.
2. The current regulations for day visual flight rules helicopter operations focus primarily on defences designed to avoid inadvertent flight into instrument meteorological conditions (IIMC). Consequently, there was no requirement for the occurrence pilot to be trained for, or for the aircraft to be equipped with technology that would assist with, recovery from an IIMC encounter.
3. Great Slave Helicopters adopted an approach consistent with the current regulations that relies on a pilot’s ability to avoid inadvertent flight into instrument meteorological conditions (IIMC). As a result, the occurrence pilot lacked the skills to recover from the IIMC.
4. 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.
5. 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.
6. When the helicopter, being operated under day visual flight rules, approached the highest elevation on Griffith Island, the uniformly snow-covered and featureless terrain, an overcast sky, and snow squalls likely created a flat light and whiteout conditions that resulted in instrument meteorological conditions.
7. While the pilot was likely attempting to visually manoeuvre the helicopter in response to inadvertent flight into instrument meteorological conditions, an unintentional descent resulted in the helicopter impacting the terrain on a near-reciprocal track to the intended route

Findings as to risk

These are conditions, unsafe acts or safety deficiencies that were found not to be a factor in this occurrence but could have adverse consequences in future occurrences.

1. 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.
2. 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 as a result of lost visual references.
3. If standard operating procedures for single-pilot operations are not required for Canadian Aviation Regulations subparts 604, 702, 703, and 704 operators, those single pilots may not be provided with vital decision-making support, increasing their potential to operate with levels of risk higher than necessary.
4. If Transport Canada does not require all Canadian Aviation Regulations Part VII operators to have a safety management system and does not evaluate these systems for effectiveness, there is a risk that operators will rely on inadequate processes to manage safety.
5. 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, increasing the risk of a collision with terrain.
6. If emergency locator transmitters that do not meet the latest design and crashworthiness standards continue to be used, potentially life-saving search and rescue services can be delayed if such a transmitter is damaged or destroyed in an occurrence, increasing the risk to the safety of passengers and crew.