Incident Summary
On 5 October 2012, approximately 17:08 Korean Standard Time, Eastar Jet Flight 223, a Boeing 737-700 aircraft registered as HL8207, experienced an in-flight engine shutdown (IFSD). The aircraft had departed from Gimpo International Airport bound for Jeju International Airport. At the time of the event, the aircraft was flying at an altitude of 22,500 ft approximately 77 km south of Gimpo. The flight crew heard a bang and observed all engine parameters shifting. The captain declared an emergency, executed engine shutdown procedures, and returned to Gimpo International Airport, where the aircraft landed safely.
Flight History
The flight departed from runway 32L at Gimpo International Airport at around 16:56. About 12 minutes into the flight, while at 22,500 ft, the right engine (#2) experienced a sudden failure. The crew followed the non-normal checklist for engine failure and initiated a return to the departure airport. The aircraft landed without further incident. Aboard were 2 flight crew, 3 cabin crew, and 146 passengers. There were no injuries.
Aircraft and Engine Information
The aircraft was a Boeing 737-700, serial number HL8207, powered by two CFM56-7B engines. The right engine sustained significant internal damage due to the liberation of a high-pressure turbine (HPT) blade. The investigation focused on the condition and failure of the HPT blades.
Investigation Findings
The Aviation and Railway Accident Investigation Board (ARAIB) conducted a detailed examination of the engine. The disassembly inspection revealed that one HPT blade had separated from the turbine disk, causing extensive damage to the engine interior. Metallurgical examination of the failed blade was performed, and the blade was found to have fractured at the transition zone between the airfoil and the platform. The cause of the blade liberation was determined to be a fatigue crack that originated from a defect in the blade coating.
Cause
The ARAIB determined that the cause of the serious incident was the liberation of one HPT blade of the right engine, which caused severe damage to the engine interior, resulting in the in-flight engine shutdown.