What happened
On 5 October 2012, an Eastar Jet B737-700, registration HL8207, experienced an in-flight engine shutdown while climbing through approximately 22,500 feet. The aircraft was operating flight 223 from Gimpo International Airport to Jeju International Airport. During the climb, the crew heard a loud bang and felt the aircraft yaw to the right. Following the event, the right engine's N1 speed dropped significantly, and an engine failure message appeared on the EGT indicator.
The flight crew immediately declared an emergency and initiated procedures to shut down the malfunctioning engine. They requested a descent and a return to Gimle International Airport. The crew followed the required non-normal checklists, managing the aircraft under autopilot until the final approach. The aircraft landed safely at Gimpo International Airport with no injuries to the 146 passengers or the five crew members on board.
The investigation
The ARAIB conducted a thorough examination of the engine and its components. Post-flight borescope inspections revealed extensive internal damage, including missing airfoils on all high-pressure turbine (HPT) and low-pressure turbine (LPT) stage 1 blades. Significant metal debris was also discovered in the turbine exhaust nozzle.
Further engine disassembly and metallurgical analysis focused on the HPT blades. Investigators examined the condition of the blades, the thickness of internal coatings, and the presence of any fatigue cracks. The investigation also reviewed the flight crew's response to the engine failure and the airline's maintenance and inspection protocols.