What happened
On May 16, 2016, an Airbus A319-132 operating a flight from Dresden to Düsseldorf experienced a serious disturbance during its approach to Düsseldorf Airport. While descending through flight level 160 near the Warburg radio beacon, the flight crew detected smoke and an odor within the cockpit. The smoke was visible for several seconds, while the odor persisted until landing.
In response to the situation, the pilots immediately donned oxygen masks and declared a Mayday, requesting a direct approach to runway 23L. The crew also communicated with the cabin crew, who confirmed that the odor was also perceptible in the passenger cabin and that flight attendants in the aft galley had donned protective breathing equipment. Due to the time constraints of the final approach, the crew did not perform the Smoke Fumes Removal checklist, prioritizing the coordination of an immediate landing.
The aircraft landed safely at Düsseldorf without any injuries to the 142 passengers or the 5 crew members. Following the landing, the aircraft sustained minor damage, and the crew underwent medical examinations at a local hospital.
The investigation
The BFU examined the cockpit voice recorder (CVR) and flight data recorder (FDR), which confirmed an Avionic Smoke Detection warning on the ECAM at approximately 21:36 local time. The investigation also focused on the aircraft's hardware, specifically the components responsible for cockpit power supply.
Findings
Technical analysis by the airline's maintenance facility identified a static inverter as the source of the odor and smoke. Subsequent laboratory examination of the component by the BFU revealed that a circuit board and a capacitor within the inverter showed evidence of heat development.
Further information provided by the static inverter manufacturer indicated that a supplier of the specific capacitor (C306) had identified quality deficiencies in their production line. This led to a production change and the issuance of a service bulletin to replace the capacitor with an optimized version in existing units.