**A latent mechanical defect in the engine fire pushbutton** has been flagged by the British Airline Pilots Association (BALPA) as a potential cause of uncommanded engine shutdowns in flight. The issue affects certain Airbus A320neo and A350 aircraft, and two incidents have already been reported. For aviation professionals, this highlights the importance of understanding cockpit systems and the potential for hidden failures. The engine fire pushbutton, located on the overhead panel, is a critical control used by pilots to isolate a malfunctioning engine. When activated, it cuts fuel supply, electrical circuits, and bleed air to the engine, and arms the fire extinguishing system. In normal operation, the button remains depressed and protected, requiring deliberate action by the crew to trigger it. However, a deformed retaining pin in the button's mechanism can cause it to release spontaneously, leading the system to interpret this as a crew command and initiate engine isolation. BALPA describes the defect as "serious" and "completely latent," with no ECAM warning before it occurs. Pilots may first receive incomplete or confusing indications, making the situation particularly challenging. The first documented event occurred on December 1, 2024, when an Air New Zealand A320neo experienced an uncommanded engine shutdown en route from Wellington to Sydney. The crew declared Mayday and diverted to Auckland, landing safely. The New Zealand Transport Accident Investigation Commission (TAIC) identified a deformed retaining pin as the cause. A second event involved a British Airways A350-1000 flying from Las Vegas to London Heathrow in February 2026. The engine shut down in cruise over Canada, and the crew noticed the fire button had popped out. After resetting it and coordinating with maintenance, they successfully restarted the engine and continued to London. This incident has not yet been officially linked to the same defect, but BALPA urges caution. In response, the European Union Aviation Safety Agency (EASA) has issued an airworthiness directive for certain A318, A319, A320, and A321 aircraft with specific fire panels. Airlines are required to inspect the fire pushbutton assemblies and replace any with deformed pins. Some inspections may be deferred until November 2027, depending on configuration. The A350 is not covered by this directive, but BALPA recommends that crews pay close attention to the overhead panel when any unusual engine, fuel, electrical, or bleed air messages appear. While the risk is considered low, the potential consequences are severe, especially during takeoff or initial climb.