What happened
During an air taxi commuter flight between two Hawaiian islands, an aircraft carrying the pilot and eight passengers experienced a catastrophic engine failure. Shortly after takeoff, while the aircraft was approximately 500 feet above the ocean, a loud bang was heard, followed by a complete loss of engine power. Realizing the aircraft lacked the range to return to the airport, the pilot performed a ditching in the ocean.
All occupants successfully exited the aircraft. One passenger managed to swim to shore, while rescue teams recovered the pilot and the remaining seven passengers from the water approximately 80 minutes later. Tragically, one fatality occurred when a passenger died before rescuers arrived. The autopsy determined the cause of death was acute cardiac arrhythmia caused by hyperventilation. Notably, the deceased passenger was found wearing a partially inflated infant life vest.
Findings
Post-accident analysis of the engine revealed that multiple compressor turbine (CT) blades were fractured and showed signs of thermal damage. The damage to the CT shroud was consistent with high-energy impacts from liberated blades. While the thermal damage was a secondary effect of increased fuel flow following the initial loss of compressor speed, the extent of the heat damage prevented investigators from identifying the original cause of the blade fractures.
Maintenance records indicated the engine had exceeded its original manufacturer-recommended time between overhaul (TBO) of 3,600 hours. The operator had implemented a Maintenance on Reliable Engines (MORE) Supplemental Type Certificate (STC) program, which extended the TBO to 8,000 hours. Although this program required more frequent borescope and compressor inspections, it did not explicitly mandate a metallurgical evaluation of the compressor turbine blades. However, such an evaluation was required by the engine manufacturer's service bulletin and maintenance manual. The operator failed to perform the required metallurgical evaluation of the blades, partly due to confusion regarding the combined guidance of the STC and the manufacturer's instructions.
Additionally, the lack of a pre-flight safety briefing by the pilot was noted. The absence of instructions regarding the location and proper use of flotation equipment likely contributed to the passengers using incorrect life vest sizes during the ditching.