KLM power-bank fire becomes a criminal investigation

A small power bank has led to a much larger investigation. KLM has reported a September 17 onboard fire to police, Dutch public broadcaster NOS reported on November 13. Prosecutors confirmed that aviation police are conducting a criminal investigation. The flight was bound for Curaçao, a constituent country of the Kingdom of the Netherlands. The development brings a familiar phone accessory into an unusually consequential setting.

The crew extinguished the fire and the Boeing 777 turned back after several hours in the air. The airline did not specify the allegation. A report to police is not a verdict. Investigators must establish responsibility. The consequences of a single battery failing extend well beyond its owner, affecting the people sharing a cabin and the crew responding to an emergency.

KLM’s current guidance counts power banks as spare batteries, permits at most two, and requires passengers to keep them with them rather than in an overhead bin. Neither using nor charging them onboard is permitted. A missing watt-hour label can also prevent carriage. Think of watt-hours as the size of an electricity tank: ideally, 100 watt-hours could run a 10-watt device for ten hours, before losses. Passing a size limit does not mean every use of that stored energy is allowed during a flight.

The US Federal Aviation Administration describes the central hazard as thermal runaway: a battery’s internal heating can become a self-accelerating process. A useful analogy is a flywheel speeding up instead of settling down. Damage, overheating and manufacturing defects are among the possible triggers. FAA guidance keeps power banks in the cabin, including when a carry-on bag is unexpectedly checked at the gate. It tells passengers to alert the crew immediately to overheating, swelling, smoke or fire. Those warning signs call for attention, not another attempt to finish charging a phone.

Location matters alongside product design. A battery buried in luggage is harder to notice and reach than one kept accessible. Rules about storage therefore serve a different purpose from limits on capacity. The KLM investigation still has facts to establish, but travellers can already separate two questions when reading their operating airline’s instructions: may this battery come aboard, and may it be used? Treating those as distinct decisions is more useful than assuming permission at the boarding gate covers everything that happens afterward.

Original publication: NOS, November 13, 2026, 22:06 Beijing time / 9:06 AM EST.