What happened
On July 2, 2018, Far Eastern Airlines flight FE8026, an Boeing MD-82 with registration B-28035, was on approach to Taipei/Songshan Airport when the left engine suffered a sudden failure. The flight, which had departed from Penghu Airport with 165 passengers and 6 crew members, was approximately 9.6 nautical miles from the runway threshold when the crew heard a loud bang.
Following the noise, the flight crew observed a drop in N1 speed and engine pressure ratio (EPR) alongside a significant increase in exhaust gas temperature (EGT) on the left engine. The crew declared a "pan-pan" urgency signal. Despite the engine failure, the crew elected to continue the approach to land as quickly as possible, as the aircraft remained controllable and the runway was already in sight. The aircraft landed safely at 19:07, and all 171 occupants were unharmed.
The investigation
The Taiwan Transportation Safety Board (TTSB) conducted an investigation into the engine failure and the subsequent uncontained event. The investigation focused on the physical damage to the JT8D-219 engine and the maintenance history of the low-pressure turbine (LPT) components.
Investigators examined the engine hardware and found that a single 4th-stage LPT rotor blade had fractured due to high-cycle fatigue. This initial fracture triggered a chain reaction: the imbalance caused five 4th-stage stator vanes to detach, shifted the number 6 bearing, and led to the breakage of 57 additional 4th-stage LPT rotor blades. The resulting debris struck the turbine bypass case and the engine cowling, causing the uncontained failure.
Additionally, the investigation reviewed maintenance records regarding airworthiness directive CAA-2011-03-013. It was discovered that two of the previous three inspections for shroud notch wear had been performed while the engine was off-wing, which did not comply with the requirement to perform such inspections while the engine is installed on the aircraft.