What happened
During the takeoff roll, the aircraft experienced an uncontained failure of the 10th stage compressor disk within the right engine. Following the failure, the flight crew initiated a takeoff abort. An engine fire was reported to the crew, which necessitated an emergency evacuation of the aircraft.
The investigation
Investigators performed a metallurgical inspection of the failed compressor disk. The analysis determined that the component had received insufficient nickel plating during a rework process conducted at the operator's facility 38 flight hours and 33 cycles before the incident. This inadequate plating led to the cadmium embrittlement of the steel disk.
Findings
- The inspection revealed that the NiCad plating process lacked necessary oversight.
- The operator had no written procedures defining the required process parameters or rectifier set-ups for the NiCad plating process.
- Personnel working on the NiCad plating line lacked any mechanism to verify the thickness of the nickel plating during the plating procedure.