EgyptAir A320 crash: Circumstances of oxygen leak and ignition source remain unclear

While French investigators believe an intense oxygen-fuelled cockpit fire brought down an EgyptAir Airbus A320 eight years ago, they have yet to determine fully the reasons for the oxygen leak and pinpoint the source of ignition. Investigation authority BEA has dismissed the Egyptian air accident commission’s official explanation – detonation of explosive material behind the cockpit – for the fatal 19 May 2016 accident. But it acknowledges that, despite extensive tests, establishing the precise mechanism for the fire’s initiation has “not been possible”. It is unable to state whether the oxygen leak or the fire came first. BEA says, however, that the speed at which the blaze developed “favours” a hypothesis of internal damage to the first officer’s oxygen system. It has theorised that a component failure, either in the first officer’s oxygen mask storage box or the upstream distribution system, or perhaps the pressing of the ‘emergency’ knob on the mask itself, triggered a flow of oxygen. While conducting studies into the ignition source, BEA learned about three recent in-flight oxygen-leak incidents on A320-family aircraft during 2022-23. Initial analysis of these incidents, it says, suggests faulty installation or adjustment of the regulator which controls the cockpit-oxygen cylinder could cause overpressure of the oxygen system. Overpressure could lead oxygen-mask regulators to fail and a high-pressure leak could occur in one, or all, of the masks. BEA points out that the first sign of oxygen flow during the accident came via the first officer’s mask regulator.<br/>