June 3, 2021
TSB reports on 2020 Nunavut runway excursion, low visibility approach
Transportation Safety Board of Canada on May 25 released its investigation report (A20C0037) focused on a 2020 runway excursion in Kugaaruk, Nunavut, involving a Buffalo Airways Ltd. Beechcraft King Air A100 aircraft. As a key contributing factor of the event, Transportation Safety Board (TSB) notes this report highlights a recurring issue of approaches being continued in low visibility environments.
The investigation, explains TSB, found that the flight crew believed the landing was permitted given the absence of an approach ban, and landed even though the reported ground visibility was below the minimum aerodrome operating visibility.
On April 28 2020, TSB explains a Buffalo Airways King Air A100 was conducting a charter flight under instrument flight rules, from the Cambridge Bay Airport, Nunavut, to Kugaaruk, Nunavut, with two flight crew members and freight on board. Immediately after touchdown at the Kugaaruk Airport, TSB explains the aircraft veered to the right and departed from the runway surface, coming to rest after colliding with a snowbank on the northwest side of the runway. The crew was uninjured and egressed the aircraft via the main cabin door. There was no fire, notes TSB, but the aircraft sustained substantial damage.
The TSB investigation determined, that during the later stages of the approach, a crosswind from the left, and the visual effects of blowing snow contributed to the aircraft being aligned with the right side of the runway. The aircraft touched down near the right edge of the runway and, explains TSB, when the right landing gear impacted the deeper snow along the runway edge, the aircraft veered to the right and departed the runway surface.
TSB states approaches to airports north of 60°N latitude are not restricted by ground visibility and, as a result, the flight crew continued the approach when the reported visibility was 1/4 statute mile, which is lower than the published advisory visibility of 1 3/4 statute miles for this approach. TSB notes the flight crew believed that the lack of an approach ban permitted a landing, and landed at Kugaaruk Airport even though the reported ground visibility was below the minimum aerodrome operating visibility of 1/2 statute mile.
TSB states the rules that govern instrument approaches in Canada are too complex, confusing and ineffective at preventing pilots from conducting approaches that are not allowed, or banned, because they are below the minimum weather limits. In 2020, the TSB issued recommendations A20-01 and A20-02 calling on Transport Canada (TC) to review and simplify operating minima for approaches and landings at Canadian aerodromes and to introduce a mechanism to stop approaches and landings that are actually banned.
In a response to both recommendations, TSB notes how TC stated that it would be forming and leading an industry working group to draft a Notice of Proposed Amendment to update approach ban regulations, as well as the supporting documentation and guidance. Until these recommendations are fully addressed, TSB explains there remains a risk that flight crews will initiate, or continue, approaches in weather conditions that do not permit a safe landing.
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