Southwest will begin a new policy requiring portable charging devices to be kept in plain sight on Wednesday, May 28. Power banks in use during flights can't be stashed in carry-ons or overhead bins.

Citing safety concerns, Southwest Airlines will no longer allow passengers to charge devices with a power bank stowed inside a carry-on bag—going further than current FAA guidance.

The fire, which began on Jan. 28 while preparing for departure to Hong Kong, was first detected by a flight attendant in an overhead luggage bin in the rear left-hand side of the plane, Air Busan ...