Incident Overview

Description
The captain was Pilot Flying (PF) for a commercial flight from Stansted Airport to Newcastle Airport, U.K.. The forecast surface wind at Newcastle was from 230ø at 28 kt, gusting to 38 kt, with a 40% probability that the strength could temporarily increase to 38 kt, with gusts to 55 kt. This night-time flight proceeded normally and the aircraft was established on an ILS approach for Newcastle’s runway 25. The runway was reported as damp, with the surface wind from 240ø at 30 kt, gusting to 43 kt when landing clearance was given. ATC provided further surface wind checks of 240ø at 37 kt and then of 240ø at 27 kt, two minutes and one minute before touchdown, respectively. The pilots reported that the approach felt bumpy but not unduly turbulent, and they were satisfied that neither the operator’s maximum crosswind limit of 30 kt nor the maximum operating wind speed of 50 kt were likely to be exceeded. The aircraft was configured with the flaps set to 22ø for landing, and the target approach speed (VAPP) was 139 kt, 15 kt greater than the calculated reference speed (VREF) to allow for the wind. The pilots recalled the wings were kept almost level until the flare commenced, with the aircraft’s nose pointing slightly left of the runway centreline, to compensate for the crosswind. Just before touchdown, the aircraft rolled left rapidly. The PF turned the control wheel right, to counteract what he and the co-pilot both perceived to be a sudden gust from the right, and they thought that the aircraft subsequently touched down smoothly. Neither of the pilots heard any aural warnings and they proceeded to a parking area where the aircraft was shut down and the passengers were disembarked. An ATC controller thought he saw a spark from the vicinity of the aircraft when it landed and asked an airfield operations officer to investigate. A technician, working abeam the touchdown zone, told the operations officer that the aircraft had seemed to roll to one side while landing. The operations officer inspected the runway and found witness marks, which started approximately 270 m from the displaced threshold and 1 m to the left of the runway centreline. Following the accident, surface abrasions were noted to the left wingtip fairing and the left aileron. Subsequent examination proved that the wingtip fairing could be repaired but the aileron was damaged beyond acceptable limits and was replaced. The pilot’s impression was that there was a sudden, large gust of wind from the right while flaring to land. Recorded data suggested the aircraft’s roll to the left during the flare was more likely caused by a sudden slackening of the strong gusty wind, from slightly left of the runway centreline. The maximum angle of bank recorded was 12.8ø at 4 ft radio altitude; less than the angle calculated by the manufacturer for a wingtip strike with the left wheel touching the ground. However, this calculation does not allow for aerodynamic loads and does not account for the runway sloping away from the centreline. The AAIB was not informed of the accident until a month later. Meanwhile, the CVR had not been preserved but flight data was available from the operator’s FDM programme.
Primary Cause
Sudden wind gust from the right during flare, likely exacerbated by a slackening of the wind, causing a rapid left-side roll.Sudden wind gust from the right during flare, likely exacerbated by a slackening of the wind, causing a rapid left-side roll.Share on: