The Transportation Safety Board of Canada has warned of the continuing danger of inadvertent flight into instrument meteorological conditions (IIMC) as it released its report into the fatal crash of a West Coast Helicopters Airbus AS350 B2 on the west coast of British Columbia’s Vancouver Island.
The accident took place in the morning of Aug. 15, 2024, on the Brooks Peninsula, as the aircraft was on the third of nine flight legs scheduled for the day.
Having departed from Port McNeill Aerodrome, the aircraft, with the pilot and one passenger on board, flew to a job site to confirm where equipment would be delivered.
It then flew to a staging area and dropped the passenger off, and a load was then attached to the helicopter’s long line. It flew south, with the pilot reporting over radio that the load was within weight limitations and stable.
About 10 minutes later, it approached a ridge to the north of the job site, but did not cross it. Instead, it turned east, flew south, and approached the job site again – this time from the southeast.
It hovered over the job site for two minutes, then departed “for unknown reasons,” flying about 800 feet southeast before returning.
It hovered over the job site again – this time for three minutes, at about 100 feet above ground level. It then flew northeast and began a shallow climb.
Its final recorded GPS position was sent about 20 seconds later, with the aircraft traveling at about 60 knots with a final descent rate of more than 9,000 feet per minute.
The pilot was killed as the aircraft hit the ground in a gully about 1,000 feet away from the job site.
Accident investigators said an impact scar and evidence from the long line indicated it was released in flight, with no evidence that it came into contact with trees or the ground beforehand.
Analysis of the aircraft’s wreckage showed no sign of a system malfunction that would have affected it controllability, the TSB said.
Weather analysis provided by Environment and Climate Change Canada showed that conditions near the crash site included cloud bases as low as 400 feet above ground level at Tofino/Long Beach Airport, about 96 nautical miles away.
“Given that the accident site was at an elevation of 1,867 feet ASL, it is likely that the surrounding area was obscured at the time of the accident,” the report states.
“During search efforts, approximately two hours after the accident, the search pilot reported that the visibility in the vicinity of the job site varied from good to completely obscured by cloud or fog.”
In its closing safety message, the report notes that visual flight rules (VFR) flight in reduced-visibility conditions is particularly hazardous in mountainous terrain.
“To mitigate the risks associated with IIMC, it is important for operators and pilots to establish — and adhere to — operational visibility and altitude limits,” it states.
“These limits are sometimes referred to as en route decision triggers and they support pilot decision making by defining minimum visibilities and/or altitudes that once reached, necessitate alternative action.”
The TSB also referenced the three recommendations to mitigate the risk of IIMC it issued following an investigation into the crash of an AS350 B2 on Griffith Island, Nunavut, in April 2021.
“The Board recommended that actions be taken to ensure that pilots possess the skills necessary to recover from IIMC; that technology be implemented on commercial helicopters to assist pilots with the avoidance of, and recovery from, IIMC; and that reduced-visibility helicopter operations requirements be enhanced.”
