What happened
On the morning of September 15, 2010, a Widerøe flight, WIF701, was conducting a scheduled service from Bodø to Sandnessjøen Airport Stokka. The aircraft, a Bombardier DHC-8-103 with registration LN-WIF, was carrying two pilots, two cabin crew members, and three passengers.
During the approach to runway 03, the crew was monitoring specific company wind limitations for the airport, which restrict landings to a maximum wind speed of 15 knots when winds originate from the 060-150 degree sector. While the most recent wind information provided to the crew indicated speeds between 9 and 15 knots, a sudden gust increased the wind speed to 17 knots just as the aircraft was approaching the ground.
As the radio altimeter indicated 20 feet, the pilots experienced a significant increase in the rate of descent. The pilot flying, who was a captain candidate undergoing line training, attempted to execute a go-around by advancing the throttles, but the aircraft struck the runway before the power could be applied. The impact was heavy, causing the right main landing gear to collapse and the aircraft to settle on its side. Despite the impact, the crew maintained the aircraft on the runway, and an evacuation was successfully carried out without any injuries to the zero fatalities or injuries recorded.
The investigation
The Norwegian Safety Investigation Authority (NSIA) examined the flight data, cockpit voice recordings, and the mechanical state of the aircraft. The investigation focused on the flight crew's experience levels, the meteorological conditions at the time of arrival, and the structural integrity of the landing gear. Investigators also reviewed the company's specific wind restrictions for Sandnessjøen Airport and the technical design of the aircraft's landing gear components.
Findings
- The aircraft experienced a hard landing due to a combination of a steep approach angle, limited flight experience of the pilot flying, and a sudden change in wind velocity.
- The right main landing gear collapsed because the vertical and horizontal forces exerted during the impact exceeded the structural limits of the fuse pin, causing it to break as designed.
- The aircraft was rolling to the right with a low right wing at the moment of impact, while also drifting right of the runway centerline.
- All operational and technical factors, including wind speeds and crew certifications, were within established regulatory and company limits prior to the sudden gust.