Incident
On May 26, 2011, a Korean Air Airbus A330-300, registration HL7553, was climbing through 11,500 feet when the crew heard a loud bang from the number 2 engine. The bang was followed by a high increase in engine vibration. Approximately two minutes later, the exhaust gas temperature (EGT) of the Pratt & Whitney PW4168A engine rose above 705 degrees Celsius, and the crew received stall and fire warnings.
Response
The flight crew responded by shutting down the number 2 engine and discharging one fire bottle. The aircraft performed an air turnback and returned to the departure airport, where it landed safely. No damage to the airplane structure or other systems was reported.
Inspection
A post-flight inspection of the number 2 engine revealed a puncture in the Low Pressure Turbine (LPT) case measuring approximately 60 centimeters by 10 centimeters at the 11 o'clock position. Additionally, two small holes were found, and metal parts were observed in the exhaust and cowling area. There was no damage to the airplane.
Investigation
Investigation of the incident is being conducted by the government of Korea through the Aviation and Railway Accident Investigation Board (ARAIB). Further details regarding the event may be obtained from the ARAIB.