What happened
On 18 December 2010, a Britten-Norman Islander BN2B-26, registration G-BPCA, was conducting a commercial passenger flight from Papa Westray to Kirkwall Airport. During the approach, the pilot encountered intermittent snow showers. To avoid disrupting ongoing snow clearance on the primary runway (09/27), the pilot elected to use the shorter Runway 14/3 to, which had a light covering of snow.
As the aircraft reached the runway threshold, a heavy snow shower suddenly enveloped the aircraft, reducing visibility to less than 100 metres. During the flare, the pilot observed tyre tracks on the ground and believed the aircraft was positioned over the runway. However, the aircraft actually touched down approximately 20 metres to the side of the runway pavement. The pilot held the aircraft in the flare to assess the situation, noting a dark cloud at ground level and an aircraft holding nearby. The aircraft subsequently taxied to its parking position without further incident.
The investigation
The AAIB examined the circumstances surrounding the approach and the visibility conditions at the time of landing. The investigation looked into the operational agreement between the aircraft operator and the aerodrome authority, which allowed for landings on the shorter runway during snow-clearing operations to minimize disruption. The investigation also reviewed the visibility-related markings on Runway 14/32, which relied on 300 mm high blue edge markers.
Findings
- The primary cause of the excursion was a sudden snow shower that significantly reduced visibility at the threshold.
- The pilot's perception of the aircraft's position was influenced by tyre tracks on the ground, which suggested the aircraft was over the runway.
- The blue edge markers for Runway 14/32 had become obscured by snow accumulation.
- The decision to use the shorter runway, while intended to minimize disruption to snow clearance, placed the aircraft on a surface with less snow than the main runway but without the benefit of instrument landing systems or full lighting.
Safety action
Following the incident, the operator suspended the arrangement that allowed the aerodrome to be opened for inter-island operations during snow-clearing periods. The parties agreed to seek better coordination to ensure operations could run on schedule without being impacted by snow clearance. Additionally, the operator updated its instructions, now requiring pilots to perform instrument approaches if reported visibility is below 3,000 metres.