What happened
On March 18, 2020, at approximately 09:05 UTC, a Vietnam Airlines Airbus A321, registration VN-A392, was performing flight VN920 from Ho Chi Minh City to Phnom Penh. During the takeoff roll, as the aircraft reached a speed between 100 and 120 knots, the crew heard a loud explosion originating from the right side of the plane. Following the explosion, the aircraft began to veer toward the right side of the runway. The captain initiated a rejected takeoff procedure in accordance with the aircraft operation manual, successfully bringing the aircraft to a halt on the runway.
Following the stop, the crew notified Air Traffic Control and followed ECAM instructions to manage the situation. This included shutting down the number two engine and deploying the number one fire extinguisher for that engine. All passengers were evacuated via ladder truck and returned to the terminal without no injuries reported for either passengers or crew.
The investigation
The CAAV launched an investigation into the incident, which included the recovery of the Flight Data Recorder and Cockpit Voice Recorder for analysis. International agencies, including the NTSB (USA) and the BEA (France), were notified to assist in the investigation of the aircraft and engine components.
Investigators identified damage to the number two engine and recovered two fragments of the High Pressure Turbine (HPT) 1st stage disc. These fragments were sent to the engine manufacturer, Pratt & Whitney, for metallurgical examination. The investigation involves ongoing collaboration between the CAAV, NTSB, and BEA to analyze flight data and physical evidence.
Findings
Preliminary assessments suggest that the engine explosion was likely caused by a manufacturing anomaly in the HPT 1st stage disc. This suspicion was shared by the NTSB and Pratt & Whitney during the early stages of the inquiry.
Safety action
Following the issuance of an Emergency Airworthiness Directive (AD) by the FAA, the CAAV immediately deployed this directive to all operators utilizing the V2500 engine series to ensure continued operational safety.