What happened
The aircraft departed from Dallas, Texas, and was in the climb phase of flight when the right engine experienced a catastrophic failure. At approximately 19 minutes after takeoff, while climbing through an altitude of 19,000 feet, a blade detached from the fourth stage turbine wheel of the right engine. This event caused varying degrees of damage throughout the entire engine assembly, leading to an automatic shutdown.
Following the loss of power in the right engine, the flight crew initiated a return to the departure airport. The aircraft landed safely on a single engine without further incident.
The investigation
Post-accident examination of the failed turbine blade revealed that the fracture was caused by metal fatigue. Analysis determined that this fatigue originated from excess porosity present in the material at the time the blade was originally cast. This manufacturing imperfection indicates a defect inherent to the production process rather than operational wear.
The engine manufacturer reviewed the findings and concurred with the investigation's conclusions. They acknowledged that their standard inspection methods should have detected this specific porosity imperfection prior to installation, resulting in the rejection of the defective blade had it been identified during quality control.
Findings
The failure occurred after approximately 400 hours of operation. The root cause was traced directly to a manufacturing defect rather than pilot error or maintenance oversight. The excessive porosity within the cast metal compromised the structural integrity of the blade under operational stress.
Safety message
This incident highlights the critical importance of rigorous quality control and inspection protocols in aerospace manufacturing. Detecting material imperfections such as excess porosity during the casting and pre-installation phases is essential to preventing in-flight component failures.