What happened
On March 18, 2020, a Vietnam Airlines Airbus A321, registration VN-A392, was performing a commercial takeoff from runway 25L at Tan Son Nhat International Airport in Ho Chi Minh City. As the aircraft accelerated, the crew reported a loud explosion originating from the right side of the aircraft. The flight crew immediately initiated a rejected takeoff procedure. The aircraft managed to come to a safe stop on the runway, and all 152 passengers and 7 crew members disembarked via ladder cars without injury.
The investigation
The Civil Aviation Authority of Vietnam (CAAV) conducted the investigation, coordinating with the engine manufacturer, the aircraft manufacturer, and international agencies including the NTSB and BEA. Investigators examined the flight data recorder, cockpit voice recorder, and wreckage. The investigation focused heavily on the second engine, which sustained major damage. Metallurgical analysis was performed on fragments of the High Pressure Turbine (HPT) 1st stage disc, which had broken and been ejected from the engine. This analysis included examining the disc's hub and the presence of specific chemical inclusions.
Findings
- The second engine suffered an uncontained failure where the HPT 1st stage disc fractured and parts were thrown from the engine.
- The failure caused significant damage to the aircraft, including a torn thrust reverser, damaged fan cowling, and structural scratches to the wings and fuselage.
- Debris from the engine failure struck the runway, causing small holes in the pavement and igniting grass near the runway edge.
- One fragment of the turbine disc was thrown far enough to strike a weather radar station, breaking an office window.
- Preliminary evidence from the engine manufacturer suggested a manufacturing anomaly within the HPT 1st stage disc.