A helicopter company flying out of Terrace has tightened its pre-flight procedures following an investigation into a Jan. 4, 2023 accident.
No one was injured when the pilot of a Summit Helicopters helicopter carrying four passengers to a guest lodge north of Terrace encountered whiteout and foggy conditions, causing him to lose sight of the ground before briefly touching down hard on the frozen surface of Treston Lake, a Transportation Safety Board investigation has concluded.
The impact badly damaged the skids of the helicopter but the pilot recovered and continued on to the Northern Escape Mountain Lodge just west of Treston Lake which is south of Kitsumkalum Lake.
"Once the helicopter was over the snow-covered lake, the pilot found himself in conditions of flat light, whiteout, and fog that reduced his ability to effectively assess his speed, attitude, and altitude," the transportation board indicated concerning a flight that began at the Northwest Regional Airport Terrace-Kitimat just minutes before.
"This ultimately contributed to the pilot’s loss of visual references and spatial disorientation, which led to the collision with the frozen surface of the lake."
The transportation board said Summit has added the incident's factors into its annual training regarding decision-making, situational awareness and workload management.
"Additionally, the company discovered that it was possible to skip the flight risk assessment step when filing a flight itinerary for visual flight rule operations. This issue has been rectified and it is no longer possible for pilots to file a flight itinerary for visual flight rules without first filling out a flight risk assessment."
Investigators also determined "that given the short duration of the flight, the pilot’s expectation of suitable weather conditions, a risk level that was assessed as low, and the underlying commercial pressure, the pilot decided to depart on a visual flight rules flight with localized fog conditions that were forecast on the planned route."
They also found that the pilot was informed during the flight of fog moving in around the lodge, causing him to decide to descend and follow the Kitsumkalum River to Treston Lake as visibility continued to deteriorate.
"Several factors led the pilot to decide to continue the flight, including visual cues from the river, the close proximity to the lodge, the pilot's familiarity and past success with his strategy for flight in low-visibility conditions, and the tendency for plan continuation under all of these conditions," the board added.
