Fire-suppression switch nearly doomed Airbus A320neo — BALPA issues urgent warning

A faulty fire-suppression switch in the cockpit can cause an engine to shut down unexpectedly mid-flight. The British Airline Pilots' Association (BALPA) has described the defect as carrying "potentially catastrophic consequences" and has issued a safety warning to flight crews.

The concern stems from an incident in December 2024 involving an Air New Zealand Airbus A320neo flying from Wellington to Sydney. Forty minutes after takeoff, the pilots issued a distress signal and requested an emergency landing at the nearest available airport after one of the two engines cut out for no apparent reason. The aircraft landed safely in Auckland.

The investigation found that the engine was not at fault — the fire-suppression system switch was. A small retaining pin in the switch had been bent during assembly, causing it to no longer hold the switch in the locked position. Ordinary in-flight vibration was enough to dislodge it. The aircraft interpreted this as a fire signal and automatically shut down the engine. The pilots had not touched the switch.

A very similar incident occurred less than two years later with a British Airways Airbus A350 flying from Las Vegas to London. In the middle of the night over the Atlantic off the coast of Canada, one engine shut down without warning. The crew managed to restart it after consulting ground support, discovering that the fire-suppression system had falsely activated in that engine. Disabling the system allowed the engine to restart, and the aircraft landed in London as scheduled.

BALPA notes that the risk is compounded by the location of the fire-extinguisher switches — they are mounted high on the overhead panel and are normally outside the pilots' direct field of view. Electronic warning messages do not always point directly to the actual cause. While a sudden engine failure at cruise altitude is a serious problem, occurring during climb or shortly before takeoff could prove catastrophic. The association urges crews to check the fire-extinguisher switches first when signs of malfunction appear.