Officials from the transport ministry, police and fire agencies inspect the damaged Air Busan passenger plane at Gimhae International Airport in Busan, Thursday. The aircraft was badly damaged after a fire broke out in an overhead bin, Tuesday. Newsis

Concerns have been raised about the safety risk of bringing portable batteries in carry-on luggage for flights, as a lithium-ion battery is suspected as the cause of the fire that destroyed Air Busan's passenger plane on Tuesday night.

According to the Ministry of Land, Infrastructure and Transport, Thursday, officials retrieved black boxes from the plane that caught fire at Gimhae International Airport in Busan as they prepared to formally launch a joint investigation with police and fire authorities.

The fire broke out while the airliner was preparing to take off. All 176 people on board — 169 passengers and seven crewmembers — escaped successfully, with seven sustaining minor injuries.

Witnesses said they heard a crackling sound — something like an electronic device burning — before smoke originating from a rear overhead bin began to fill the cabin, which prompted an urgent evacuation through inflatable slides.

While there are still multiple potential causes for the fire, such as a short circuit in the aircraft, suspicions grow that a portable battery may be the cause.

Just seven weeks ago, the airline had a similar incident. A fire, triggered by a portable battery problem, prompted flight attendants to use fire extinguishers to put it out.

At least two other battery-caused fire incidents occurred in Korea in 2024 — in an Eastar Jet plane in July and aboard an Asiana Airlines flight in April.

Rules on spare batteries vary by airline, but most companies allow batteries in carry-on bags. In the case of Air Busan, passengers can carry up to two lithium-ion batteries not exceeding a watt-hour rating of 160Wh or 8g of lithium content.

Aviation experts say even if the cause of the fire is proven to be a battery, it will be difficult for the carrier to hold the passenger who brought it accountable, because there are no rules against batteries inside the cabin.

Tuesday's incident came about a month after a Jeju Air plane crashed at Muan International Airport in South Jeolla Province, which killed all but two of the 181 people on board.

The plane that caught fire was a 17-year-old Airbus A321-200 built in 2007. It had been operated by Air Busan's parent company, Asiana Airlines, until it was handed over to the budget carrier in May 2017, according to transport ministry records.

Firefighters spray water to put out flames on an Air Busan passenger plane at Gimhae International Airport in Busan, Tuesday. Yonhap

The incident could have been much worse. The plane, bound for Hong Kong, was originally scheduled to take off at 9:55 p.m., but its departure was delayed by about 20 minutes. Then the fire was spotted at 10:15 p.m., just before takeoff.

The fire could have caused a major explosion as the plane was carrying some 35,000 pounds of aviation fuel. But after the evacuation of all passengers and crew at 10:36 p.m., firefighters successfully prevented the fire from spreading to the wings, where the fuel was stored, and fully extinguished it by 11:31 p.m.

Twenty-two foreign nationals were among the passengers — 18 Chinese, two Americans, one British and one Filipino. Many of the Koreans were families traveling for the Lunar New Year holiday.

At a meeting held Thursday, representatives of the transport ministry, police and firefighters discussed detailed plans for investigation after visiting the scene to examine the plane, such as how to defuel it for a safe inspection.

"If the plane catches fire again over the course of a probe, it could explode," an official said. "We would decide whether to defuel the plane (for investigation) … But it seems challenging because the fuselage was damaged."

A team of investigators from France, where Airbus headquarters is located, also arrived at the scene later that day to join the fact-finding effort, as the International Civil Aviation Organization's rule requires the participation of the nation that manufactured an affected plane in a probe.

"We will keep all possibilities open to find the exact cause of the fire," a ministry official said.