What happened
On May 6, 2016, TransAsia Airways flight ZV252, an Airbus A321-200 with registration B-22610, was operating a scheduled service from Taiwan Taoyuan International Airport to Tokyo Haneda International Airport. The flight was carrying 163 passengers and 6 crew members.
While cruising at 35,000 feet, cabin crew notified the flight deck that a passenger's power bank was emitting smoke. The crew reported that smoke and what appeared to be small explosions were visible near seat 16B. The flight crew immediately decided to divert the aircraft back to Taoyuan. To manage the hazard, the crew extinguished the fire and submerged the device in a water-filled waste bin to cool it down, subsequently securing it in a lavatory.
The aircraft commenced an emergency descent and landed safely at Taoyran International Airport at 23:21 local time. There were no fatalities and no injuries reported, and the aircraft sustained no significant damage.
The investigation
The Taiwan Transportation Safety Board (TTSB) investigated the incident, involving the Civil Aviation Administration and the Aviation Police Bureau. The investigation focused on the cause of the battery malfunction and the safety of lithium-ion battery transport.
Investigators examined the damaged power bank, noting that two of the battery cells had been completely destroyed by fire, making it impossible to determine the exact internal failure mechanism. However, testing of similar power banks from the same source revealed that they failed vibration tests, which could lead to internal structural damage. The investigation also noted that the passenger had purchased the device from an uncertified online retailer in mainland China, meaning it had not undergone local safety inspections.
Findings
- The primary cause of the incident was an internal failure or defect within the passenger's power bank, which ignited while the passenger was using it to charge a mobile phone.
- The power bank was an uncertified product purchased through an overseas online platform, making its quality difficult to regulate.
- The crew's response, including passenger evacuation, notification, and fire suppression, was in full compliance with the airline's emergency procedures.
- High volumes of lithium battery violations were noted in checked baggage at Taoyuan Airport, suggesting a need for improved passenger education regarding the requirement to carry such devices in carry-on luggage only.