What happened
On 30 October 2013, an Airbus A380-800, registration 9V-SKB, was performing a scheduled passenger service from Singapore Changi Airport to Sydney, Australia. While the aircraft was climbing through 13,000 feet, a cabin crew member noticed smoke and electrical sparks emanating from an in-flight entertainment (IFE) screen located at seat 55D.
Upon investigating, the crew observed thick smoke and visible sparks behind the display unit. The crew member immediately instructed the passenger to move away from the area and utilized a halon fire extinguisher to discharge at the screen. To mitigate the risk, the In-Flight Supervisor attempted to cut power to the row by toggling an electrical isolation switch located under the seat cushion of seat 54D. Despite this action, the crew noted that the handset remained lit and the base of the screen continued to flicker for approximately 15 minutes before the flight continued to its destination without further incident.
The investigation
Investigators examined various IFE components, including the display unit, handsets, cradles, and power modules. Testing of the display unit revealed significant heat stress on an integrated circuit chip (IC500) and a ferrite bead, as well as damage to the printed circuit board. The chip manufacturer determined that the failure was caused by electrical overstress.
Further technical analysis revealed a critical failure in the power isolation mechanism. A wire harness connecting the isolation switch to the supply power module had been severed. This breakage prevented the command to cut power from reaching the display unit, explaining why the screen's light continued to flicker even after the switch was turned off. The investigation could not confirm how the wire was severed, though a possible cause was a pinched wire during the initial seat assembly installation.
Findings
- The primary cause of the smoke and sparks was an electrical overvoltage or overcurrent condition that damaged the internal components of the IFE display unit.
- A severed wire harness prevented the electrical isolation switch from successfully disconnecting power to the affected row.
- The crew did not realize that the electrical power had not been effectively isolated, as they were not aware that the flickering light indicated a failure of the shut-off mechanism.
- There were no instructions in the maintenance manual for personnel to perform functional checks of the isolation switch following maintenance actions.
Safety action
Following the investigation, the operator enhanced its cabin crew training to include procedures for verifying that electrical power has been completely removed from affected IFE systems. Additionally, a safety recommendation was issued to the IFE manufacturer to include a requirement for functional checks of all electrical isolation switches in their installation manuals.