Narrative:A Swearingen SA.227AC Metro III, OY-NPB, sustained substantial damage in a runway excursion accident at Oslo-Gardermoen (OSL), Norway. None of the eleven occupants were injured.
|Date:||02 MAR 2011|
|Type:||Swearingen SA227-AC Metro III|
|Operating for:||Air Norway|
|Leased from:||North Flying|
|C/n / msn:|| AC-420|
|First flight:|| 1981|
|Total airframe hrs:||24833|
|Engines:|| 2 Garrett TPE331-11U-612G|
|Crew:||Fatalities: 0 / Occupants: 2|
|Passengers:||Fatalities: 0 / Occupants: 9|
|Total:||Fatalities: 0 / Occupants: 11 |
|Airplane damage:|| Written off|
|Airplane fate:|| Written off (damaged beyond repair)|
|Location:||Oslo-Gardermoen Airport (OSL) (Norway)
|Phase:|| Landing (LDG)|
|Nature:||Domestic Scheduled Passenger|
|Departure airport:||Ørland Airport (OLA/ENOL), Norway|
|Destination airport:||Oslo-Gardermoen Airport (OSL/ENGM), Norway|
The airplane operated on scheduled flight M3990 from OLA (Ørland) to OSL. During roll-out following a normal landing, when the aircraft's speed had decreased to less than 60 kt, the aircraft started an uncommanded turn to the right. The nose wheel steering system was activated. The course could not be corrected, and the aircraft veered off the side of the runway where it became stuck in hard-packed snow one metre deep.
The investigation has shown that the loss of control was most likely caused by a fault in the nose wheel steering. The same problem had occurred six days earlier, but the commander then managed to disconnect the nose wheel steering in time and regained control. The fault could not be reproduced, and the aircraft was released to service after inspection and testing without remarks.
The nose wheel steering system on this aircraft type is relatively complex, and over time several improvements have been made to improve its reliability. The Flight Manual has a caution related to activation of nose wheel steering at speeds higher than normal taxi speed.
There was some freezing rain/freezing fog at the time of the accident.
METAR: ENGM 280241Z 19003KT 7000 FEW009 BKN025 M05/M06 Q1027
Comprehensive technical examination of the nose wheel steering on OY-NPB uncovered no single causal factor, but some indications of unsatisfactory maintenance. Irregularities that alone or in combination could have caused a temporary fault with the steering were present. The Accident Investigation Board believes that a temporary fault caused the nose wheel to unintentionally lock itself in a position towards the right. No other defects or irregularities that could explain why the aircraft veered off the runway were found.
» AIBN Norway
This map shows the airport of departure and the intended destination of the flight. The line between the airports does not
display the exact flight path.
Distance from Ørland Airport to Oslo-Gardermoen Airport as the crow flies is 394 km (247 miles).