Incident Overview
On 27 March 2023, at approximately 1115 hrs local time, a Boeing 777-300ER operated by Singapore Airlines (registration 9V-SWQ) was descending into Los Angeles International Airport when a passenger at seat 48K reported smoke emanating from the in-flight entertainment (IFE) panel at the back of seat 47K. The cabin crew responded by switching off the seat power supply and discharging two fire extinguishers. After the aircraft touched down, smoke and sparks reappeared, prompting the discharge of a third extinguisher and the deactivation of the IFE master power. No one was injured.
Aircraft and Crew
The aircraft, powered by two GE90-115B engines, was operating a scheduled flight from Narita International Airport, Japan, to Los Angeles. The crew included an In-Flight Manager, a Leading Steward, and a Flight Steward, all with extensive experience and adequate rest periods. A total of 234 persons were on board.
IFE System and Damage
The affected IFE panel comprised a display, multiport jack (MPJ) with USB ports, handset, and audio jack. Electrical power to the row of seats (47H/J/K) was controlled by a seat power module (SPM) maintenance switch under seat 47H. The MPJ on seat 47K sustained heat and fire damage, as did the seat back shell casing. The MPJ's USB ports showed signs of fire damage.
Investigation Findings
Four days earlier, on 23 March 2023, the same aircraft had experienced a smoke incident from the MPJ under seat 41K, which was resolved by replacing affected IFE components. Subsequent in-depth examination by the operator revealed damaged wire and cable insulation on a folding arm-type IFE display at seat 41H, causing a short circuit that exposed the 28V IFE power supply to the chassis ground wiring system.
For the 27 March incident, the IFE manufacturer found signs of liquid ingression on the IFE frame. They concluded that the combination of damaged wires (exposing high voltage to chassis ground) and liquid- induced shorting between chassis ground and digital ground on the MPJ resulted in overvoltage and heat damage, producing smoke.
Safety Actions
The report does not specify safety actions taken by the operator or manufacturer beyond the investigation details. The Transport Safety Investigation Bureau classified the occurrence as an incident.