Preliminary report on serious aviation incident at Svolvaer airport Helle, Norway 2 December 2010 involving Bombardier DHC-8-103, LN-WIU operated by Wideroes Flyveselskap AS
The Accident Investigation Board Norway (AIBN) was made aware of the incident in December 2012, two years after it had taken place. After an assessment of the available information, the AIBN concluded in June 2013 that this was to remain an incident. An investigation was not initiated.
In February 2015 the AIBN learned that the incident might contain more significant learning potential than first assumed. Medio March the AIBN altered the decision and initiated an investigation. This is in accordance with the Norwegian Aviation Act. Based on the preliminary investigation, the incident has been reclassified to a serious aviation incident.
The preliminary report can be downloaded here.
Summary
The general weather situation in the Svolvaer area was strong southwesterly wind and gusting storm with cumulo-nimbus in the vicinity. In darkness the aircraft performed visual circling over the sea in order to land towards south.
Shortly before the aircraft should make the final turn into the final, the speed dropped significantly and the aircraft started to shake. Despite applying full engine power, the speed and altitude continued to drop. The nose was lowered and stall was avoided, but in the recovery the distance to the sea was only 25 m according to the radio altimeter. The recovery with full engine power was abrupt and the aircraft was subject to high g-forces.
Data from the FDR has been thoroughly studied and compared with explanations from those involved. The scenario as described above occurred over a 9 sec time span. Following the incident, the crew decided to abort the landing at Svolvaer and continue to Leknes where they landed normally.
The AIBN concludes that the aircraft was subject to an excessive wind shear at low altitude. In this preliminary report, the AIBN’s focus has been to describe and understand the sequence of events, how and why the control was lost and the crew succeeded in regaining control with small margins.
The flight was performed in darkness without a visible horizon and with only a few lights as reference. These are typical conditions for creating spatial disorientations. The AIBN will consider this theme in the continued investigation. Challenging weather in combination with the short field operation concept in Norway has been analysed in several previous reports from the AIBN, this is also a major topic in this investigation. In the continued investigation, the AIBN will assess risk management and safety margins present during circling in darkness.
Updated: 02.09.2015