Investigation Summary
The investigation into Flight 804 was marked by a long-standing dispute between Egyptian and French authorities. Egyptian officials initially claimed that traces of explosives were found on human remains, suggesting a terrorist act. However, French investigators from the BEA found no evidence of an explosion and instead focused on technical failures. In 2024, a comprehensive report release clarified that the fire likely started at the co-pilot's oxygen mask, which had been set to 'emergency' mode by maintenance, causing a constant flow of oxygen. This oxygen enriched the cockpit atmosphere, where a heat source—potentially a cigarette smoked by the crew—ignited a fierce fire that disabled the aircraft's control systems.
Final Conclusions
The crash was caused by a fire in the cockpit that rapidly became uncontrollable. The fire was fueled by oxygen leaking from the co-pilot's oxygen mask, which had been improperly maintained or left in a high-flow state. The ignition source was likely a cigarette, as smoking in the cockpit was not prohibited by EgyptAir at the time. The fire led to the loss of aircraft control and structural failure.
Photographic Evidence (1)
Video Analysis
The Loss of EgyptAir Flight 804: Mediterranean Sea Crash Analysis — This video examines the 2016 crash of an Airbus A320 caused by an in-flight cockpit fire. It details how a leaking oxygen mask and a heat source led to the loss of control and structural failure over the Mediterranean.
Watch on YouTube ↗If playback is blocked, the owner has disabled embedding — use the link above.
Systems & Failure Modes
Crew Oxygen System
A leak in the co-pilot's mask provided a high-concentration oxygen environment that fueled the fire.
ACARS
The Aircraft Communications Addressing and Reporting System transmitted smoke alerts before the plane lost power.
Flight Data Recorder (FDR)
Recovered from 3,000 meters depth, it confirmed smoke alerts and high-temperature events.
Interesting Facts
- 01The aircraft had logged 48,052 flight hours and was manufactured in 2003.
- 02ACARS data recorded seven fault messages within three minutes before the crash.
- 03Wreckage recovered from the front section showed soot and high-temperature damage.
- 04The co-pilot's oxygen mask had been replaced three days prior to the accident.
- 05Smoking in the cockpit was a common practice among EgyptAir pilots at the time.
Safety Actions & Advisories
Oxygen Mask Maintenance Procedures
Airbus and operators reviewed maintenance protocols for crew oxygen masks to ensure they are not left in the 'emergency' flow setting.
Cockpit Smoking Ban
EgyptAir subsequently implemented stricter rules regarding smoking in the cockpit to eliminate potential ignition sources.
Known Controversies & Unanswered Questions
Explosives vs. Technical Failure
Reference ↗Egyptian authorities claimed to have found explosive residue on victims, suggesting terrorism, while French investigators found no evidence of explosives and concluded the cause was a cockpit fire.