What happened
On March 9, 1997, a McDonnell Douglas DC-9-81, registration SE-DMX, was performing a scheduled arrival at Kiruna airport from Stockholm/Arlanda. During the approach, the flight crew was informed of icy runway conditions and specific braking coefficients. However, as the aircraft neared the runway, weather conditions deteriorated significantly, with heavy snowfall and increasing winds.
As the aircraft approached touchdown, the pilot flying managed a landing despite turbulent conditions. Shortly after contact with the runway, the captain applied reverse thrust. During this maneuver, the aircraft experienced a significant yaw to the right. In an attempt to correct the direction and maintain the runway heading, the pilot discontinued the reverse thrust and increased the braking pressure to maximum. This maneuver caused the aircraft to drift toward the left edge of the runway. Approximately 1,500 meters into the landing roll, the aircraft departed the left side of the runway, traveling parallel to the pavement for about 400 meters before coming to a halt in a half-meter of snow.
Following the excursion, the crew initiated an emergency evacuation. The process was completed in approximately 60 to 70 seconds. While most passengers exited safely, one elderly passenger sustained a serious shoulder injury and required stretcher assistance.
The investigation
The Swedish Board of Accident Investigation examined the meteorological data, aircraft systems, and airport procedures. The investigation focused on the accuracy of the wind and runway condition reports provided by air traffic control, as well as the crew's response to the aircraft's lateral movement. The inquiry also reviewed the effectiveness of the airport's rescue services and the communication between the tower and the flight crew.
Findings
- The aircraft touched down more than nine meters to the left of the runway centerline.
- The reported braking action coefficient was lower than what was actually present on the runway surface.
- The air traffic controller failed to report wind gusts that exceeded the average wind speed by more than 10 knots.
- The recommended crosswind speed limitations for the operation were exceeded.
- The pilot's decision to push the control column forward during the landing roll deviated from the aircraft's operating manual.
- There were discrepancies in the reporting of runway conditions, as the actual friction was worse than the reported values.
- The airport rescue service experienced a delay in response because a siren failed to sound due to a control relay that had not been reset.
Safety action
The investigation led to recommendations for the Swedish Civil Aviation Administration to provide air traffic controllers with more in-depth flight operational training and joint training opportunities with flight crews. Additionally, it was recommended that procedures be developed to ensure controllers can accurately report actual crosswind components upon request.