Portable battery possible cause of Air Busan fire as authorities complete on-site inspection

Authorities have completed an initial on-site inspection on Thursday as they probe a fire that broke out on Air Busan flight BX391, with eyewitnesses suggesting the blaze may have started from a portable battery stored in an overhead compartment.

Officials from the Ministry of Land, Infrastructure and Transport conduct an on-site inspection on Jan. 30 before a joint investigation to determine the cause of the fire at Gimhae International Airport in Busan. [SONG BONG-GEUN]

Authorities have completed an initial on-site inspection on Thursday, joined by officials from the French accident investigation agency, as they probe a fire that broke out on Air Busan flight BX391 at Gimhae Airport on Tuesday, with eyewitnesses suggesting the blaze may have started from a portable battery stored in an overhead compartment.

The incident occurred at approximately 10:15 p.m. on Tuesday while the Air Busan aircraft, a Korean low-cost carrier, was preparing for departure to Hong Kong. It led to the emergency evacuation of all 176 passengers and crew members.

Flames erupt from the overhead compartment inside Air Busan flight BX391, bound for Hong Kong, on Jan. 28, in this photo provided by a reader. [NEWS1]

Seven individuals suffered injuries. Fire authorities believe the severity of the situation was mitigated because the aircraft was still on the ground due to a flight delay.

A joint investigation to determine the exact point of origin and cause of the fire was delayed due to safety concerns. The aircraft contains 35,900 pounds (16,284 kilograms) of fuel in both wings, heightening the risk of an explosion if additional fires occur.

Investigators are focusing on multiple potential causes of the fire. A flight attendant reported that the fire appeared to have started from an overhead bin near row 28, according to an initial Air Busan report. Based on this testimony, authorities are examining the possibility that a passenger's portable battery, compressed within carry-on luggage, may have ignited.

Most portable batteries use lithium-ion cells, which are classified as hazardous materials by the International Civil Aviation Organization (ICAO) and the International Air Transport Association (IATA).

Korean aviation safety regulations prohibit lithium batteries from being placed in checked baggage due to the risk of combustion. However, passengers are allowed to carry a limited number on board depending on watt-hour capacity. Batteries with a capacity of 100 watts or less can be carried, with a limit of up to five per passenger. Those between 100 watts and 160 watts require prior airline approval and are generally limited to two per passenger.

Despite these regulations, lithium-ion battery fires have become a recurring issue in aviation. On Dec. 12, 2024, another battery fire occurred on Air Busan flight BX142 at Gimhae Airport. Similarly, in July 2024, a portable battery caught fire on Eastar Jet flight ZE512 from Bangkok to Incheon. Earlier that year, in April, a portable battery from the overhead bin caught fire on Asiana Airlines flight OZ8913 traveling from Gimpo to Jeju.

A notice at Incheon International Airport displays prohibited items for checked baggage, including portable batteries, on Jan. 30. [YONHAP]

Officials stress that they are keeping all possibilities open in determining the cause of the fire — including the potential ignition of electronic devices such as an e-cigarette or a short circuit in the aircraft’s electrical system.

"Although there are many mentions of a portable battery, we cannot make any premature conclusions until a thorough investigation is completed," said an official from the Ministry of Land, Infrastructure and Transport.

Some passengers criticized Air Busan’s handling of the emergency, citing the absence of in-flight announcements and a lack of clear instructions from the crew. Witnesses reported that a passenger sitting in the emergency seat, rather than a flight attendant, opened the emergency exit.

"The situation was urgent and evolving rapidly, leaving no time for separate announcements," Air Busan said in a press release on Wednesday. "The evacuation procedures were carried out promptly in accordance with emergency protocols."

The airline also said that "the emergency exit was opened by a passenger who had previously been instructed on how to do so, following the crew’s request."

Aviation experts warn that if the aircraft’s engines had been running at the time, there could have been a risk of passengers being pulled into them. Additionally, improperly deploying the emergency slide could have damaged it, hindering the evacuation process.

BY SEO JI-EUN [seo.jieun1@joongang.co.kr]