Summary
On 18 December 2012, a Boeing 787-8 aircraft operated by LOT Polish Airlines (PLL LOT) encountered a brake system anomaly after landing at Warsaw Chopin Airport (EPWA). The crew reported a brake system error following the flight. Subsequent maintenance inspection revealed mechanical damage to the No. 3 electric brake actuator (EBA), including the tearing of the rear piston cover, shearing of mounting bolts, and crushing of the brake piston stem. Parts of the stem were found inside the actuator. Additionally, minor mechanical damage was observed on the surface of the landing gear truck, likely caused by the uncontrolled movement of the EBA actuator.
Incident Details
The incident occurred on 18 December 2012 at Warsaw Chopin Airport. The aircraft involved was a Boeing 787-8, operated by PLL LOT S.A. No injuries or fatalities were reported. The investigation was conducted by the operator under the supervision of the State Commission on Aircraft Accident Investigation (PKBWL).
Cause
According to the investigation report, the most likely cause of the incident was the uncontrolled activation of the No. 3 EBA actuator. This activation caused the actuator to come into contact with the landing gear truck, resulting in damage to the actuator and minor damage to the truck. The report did not specify any contributing factors or assign further causal links.
Response
Following the incident, the operator took the following preventive actions: notification of the aircraft manufacturer (Boeing), notification of the actuator and landing gear manufacturers (UTAS/Goodrich), and transfer of the damaged No. 3 EBA actuator to a specialized workshop for examination by the manufacturer. The PKBWL issued no safety recommendations.