What happened
On January 19, 2020, at 22:38 UTC, an Embraer ERJ190-100IGW, registration LV-CKZ, operated by Austral Líneas Aéreas, departed from Astor Piazzolla International Airport in Mar del Plata, Argentina. Shortly after takeoff from runway 31, the aircraft experienced a sudden failure of the left engine, resulting in a complete loss of power from that unit.
The flight crew declared a MAYDAY emergency and initiated a return to the departure airport. After approximately twelve minutes of flight, the crew successfully performed an approach and landed the aircraft on runway 31 using only the remaining operational engine. There were no injuries among the 5 crew members or the 99 passengers on board, though the left engine sustained significant damage.
The investigation
The investigation focused on the mechanical failure of the left engine, a General Electric CF34-10E5A1. Technical analysis of the engine components revealed that the high-pressure turbine disk (manufactured by XAE) possessed a geometric profile that deviated from the intended design. This discrepancy reduced the clearance between the turbine blade and the disk surface, leading to an uneven distribution of mechanical loads.
Investigators examined the maintenance history and operational parameters of the aircraft. While the operator's engine performance parameters were slightly higher than those of other operators, the investigation confirmed that all operational limits and airworthiness guidelines were strictly respected. The investigation also reviewed the flight data and cockpit voice recordings to reconstruct the sequence of the engine failure.
Findings
- The primary cause of the engine failure was a manufacturing deficiency in the high-pressure turbine disk.
- The geometric irregularity in the disk created a concentration of stress at the contact points between the disk and the turbine blades.
- This stress concentration led to the liberation of high-pressure turbine blades, causing the loss of power.
- The defect was a latent condition that could not be detected through standard inspection or maintenance procedures available at the time of the incident.