History of the Flight
The aircraft, an Airbus A320-214 registered G-EZWM, was operating a commercial passenger flight from Liverpool to Naples. During the en-route climb at Flight Level 320, the co-pilot reported an odd odour. While the commander checked the galley area via CCTV, he observed smoke rising from the right side of the centre console near the co-pilot's knee. Both crew members donned oxygen masks. Shortly after, the ECAM displayed an 'avionics smoke' caption, and an amber smoke light illuminated on the gen 1 line pushbutton. These indications extinguished after about one minute, but visible smoke continued. The crew declared a PAN and commenced a descent, initiating avionics smoke drills from the Quick Reference Handbook. The commander handed control and communications to the co-pilot while managing the drills, cabin crew briefing, and reprogramming the flight management computer for a diversion to London Gatwick Airport. During the descent, the smoke stopped, and the aircraft landed safely on Runway 26L without further incident. The Airport Fire Service (AFS) met the aircraft and escorted it to a remote stand, where passengers disembarked via stairs. After engine shutdown, the AFS scanned the aircraft for hotspots using a thermal imaging camera but found none.
Investigation
Technicians examined the aircraft and found a static inverter in the avionics bay with signs of severe overheating. The inverter, part number 1-002-0102-1830/2A350-1AS-1830, was located below the co-pilot's footwell floor to the right of the centre console. It supplies 115V AC, 60 Hz power to a cockpit utility socket for domestic equipment such as laptops and tablets. The floor was not sealed to prevent fumes from entering the cockpit. The inverter was standard equipment on aircraft manufactured after serial number 2700.
The faulty inverter was sent to the manufacturer for examination. They determined that the damage centred on a capacitor, C306, which had been destroyed by overheating. The extent of the damage prevented establishing the precise reason for the capacitor's failure. Tests on another unit indicated that the capacitor was operating well within its allowable working temperatures. The manufacturer reviewed the reliability and failure rates of the inverter and found them acceptable. They considered this failure an isolated incident but stated they would monitor the reliability of static inverters.
Damage
The static inverter was the only component damaged; the aircraft returned to service after the inverter was replaced and further testing.