What happened
On 21 February 2016, an Airbus A3/20-233, registration SP-HAI, was operating a commercial passenger flight from Paderborn, Germany, to Birmingham International Airport. Following a landing characterized by gusty and turbulent conditions, the aircraft vacated the runway via Taxiway Bravo.
As the crew attempted to execute a 90-degree right turn onto Taxiway Alpha, the aircraft failed to complete the maneuver and ran onto the adjacent grass. The aircraft came to a stop with only a small portion of the right-hand mainwheel remaining on the paved surface. There were no fatalities and no injuries among the 6 crew members or 99 passengers on board. Following the incident, passengers were disembarked via stairs, and the aircraft was moved to a maintenance facility for inspection.
The investigation
The AAIB investigation examined flight data recorder (FDR) and cockpit voice recorder (CVR) data, as well as the physical condition of the taxiway. The FDR revealed that the aircraft entered the turn at approximately 18 knots, which exceeded the manufacturer's recommended speed of less than 10 knots for turns of 90 degrees or more. The data also showed that wheel braking had ceased shortly after the turn began and that the nosewheels had maintained a high angle of deflection.
Investigators noted that the taxiway surface was damp. While a friction test identified a small area of reduced friction where the taxiways intersected, the values were not considered excessively low. The CVR indicated that the first officer was focused on after-landing configuration tasks during the turn, and the commander did not recall any mechanical failures or abnormal indications prior to the skid.
Findings
- The aircraft entered the 90-degree turn at a groundspeed of 18 knots, significantly higher than the maximum speed of 10 knots specified in operating manuals.
- The nosewheels lost traction and began to skid early in the maneuver, likely due to the high steering angle and excessive speed.
- The damp condition of the taxiway surface contributed to the loss of directional control.
- The flight crew's attention was divided, as the first officer was performing after-landing procedures while the turn was being executed.