What happened
On 2 January 2015, a Saab-Scania SF340B, registration G-LGNL, was preparing for a commercial passenger flight from Stornoway Airport to Glasgow. The aircraft was operated with three crew members and 26 passengers on board. During the takeoff roll on Runway 18, the aircraft encountered strong and gusty crosswind conditions, with surface winds reported at 27 knots from 270°.
As the aircraft accelerated, the commander transitioned control from the nosewheel steering (NWS) wheel to the control yoke. At approximately 65 kt, the aircraft experienced a sudden and violent swing to the left. Although the pilot applied right rudder, the aircraft continued to skid, eventually departing the paved surface at an airspeed of 80 kt. The aircraft traveled 250 meters after leaving the runway, during which time the nose landing gear collapsed. The aircraft came to a halt on the grass, sustaining extensive damage to the engines, the underside, and the nose gear. During the incident, one passenger sustained a serious injury.
The investigation
The AAIB examined the aircraft's flight data recorder (FDR) and cockpit voice recorder (CVR). The FDR data showed that engine torques increased symmetrically and that the aircraft's heading changed sharply to the left at 65 kt. The investigation also reviewed the aircraft's maintenance and the crew's operational procedures. Investigators noted that the power levers remained at full power throughout the excursion and were not moved to ground idle before the aircraft came to rest. The investigation also looked into the effectiveness of the nosewheel steering and the impact of the wind conditions on directional control.