What happened
On 20 October 2023, a Boeing 737-8K5, registration G-TAWD, was performing a commercial passenger flight from Manchester to Corfu, with a scheduled return to Leeds Bradford Airport. During the landing roll at Leeds Bradford, the aircraft encountered heavy winds associated with Storm Babet. While the initial touchdown and deceleration were normal, the aircraft began to drift left of the runway centreline.
As the pilot flying attempted to correct the deviation with right rudder, both pilots experienced a significant and unusual vibration, or 'judder', originating from the nose gear. This sensation, accompanied by a perceived adverse yaw, led the pilot to limit the amount of right rudder input applied. Consequently, the aircraft continued to deviate from the centreline, eventually leaving the runway at a groundspeed of approximately 55 kt and coming to a stop in muddy ground beyond a taxiway exit. There were no injuries to the 195 passengers or 6 crew members on board, though the aircraft sustained damage to the main and nosewheel tyres and a nosewheel axle bearing.
The investigation
The AAIB investigation examined the aircraft's flight data recorder, cockpit voice recorder, and the physical condition of the landing gear. Investigators found that the left nosewheel inner axle bearing had failed. Analysis of the runway surface showed 'steam-cleaned' tyre marks, suggesting high temperatures at the tyre-ground interface, but no evidence of hydroplaning or a loss of friction was found.
Engineers from the aircraft manufacturer performed a ground track analysis and a landing simulation. The simulation concluded that the aircraft's deviation could have been prevented if more significant right rudder and differential braking had been applied. The investigation also noted that the pilot had disconnected the autobrake and stowed the reverse thrust earlier than standard procedures, which reduced the deceleration rate during a critical phase of the rollout.
Findings
- A failure of the left nosewheel inner axle bearing likely occurred during the landing roll, creating an unexpected and intense vibration.
- The pilot flying was deterred from applying sufficient right rudder due to the mechanical vibration and the perception that increased rudder input was causing an adverse yaw response.
- The aircraft's deceleration was reduced because the pilot disconnected the autobrake and stowed the reverse thrust earlier than recommended during the rollout.
- There was no mechanical impediment that physically prevented the use of additional rudder or differential braking to maintain directional control.