EgyptAir Flight 804

Investigation

According to Greek military radar data, Flight 804 veered off course shortly after entering the Egyptian flight information region. At Flight Level 370 (about 37000 ft in altitude), the aircraft made a 90-degree left turn, followed by a 360-degree right turn, and then began to descend sharply. Radar contact was lost at an altitude of about 10000 ft. This information was later denied on 23 May by an Egyptian official from the National Air Navigation Services Company, who stated there was no change in altitude and no unusual movement before the aircraft disappeared from radar. On 14 June, Egyptian authorities confirmed the statements made by Greek officials.

On 19 May, Greece's Ministry of National Defence reported that it was investigating the report of a merchant ship captain who claimed to have seen a "fire in the sky" 240 km south of the island of Karpathos.

Shortly after the disappearance, the French government began to investigate whether there had been a security breach at Paris Charles de Gaulle Airport.

Seven messages sent via the ACARS had been received from the aircraft between 02:26 and 02:29 local time; contact was lost four minutes later at 02:33. The data, confirmed by France's Bureau of Enquiry and Analysis (BEA), indicates that smoke may have been detected in the front of the airliner—in the front lavatory and the avionics bay beneath the cockpit. Smoke detectors of the type installed on the aircraft can also be triggered by the condensation of water vapour, producing fog, in the event of a sudden loss of pressure inside the cabin. The aircraft's optical smoke detectors have been deemed more reliable than older models on Airbus aircraft, as they produced fewer false warnings, but were sensitive to dust and some aerosols. The three windows mentioned in the data are cockpit windows, on the co-pilot's side. The flight control unit (FCU) is a cockpit-fitted unit that the pilot uses to enter instructions into the two flight management guidance computers (FMGC); an FCU 2 fault indicates a loss of connection between the FCU and FMGC number 2. The spoiler elevator computer number 3 (SEC 3) is one of the three computers that controls the spoilers and elevator actuators. Two pilots—one interviewed by The Daily Telegraph, the other writing for The Australian—interpreted the data as possible evidence of a bomb.

At 02:36, seven minutes after the last ACARS message and the last ADS-B transmission, two transmissions from the aircraft's Emergency Locator Transmitter (ELT) were received by the international Cospas-Sarsat system. These transmissions indicated that they were initiated in "test" mode, suggesting either an unusual manipulation of the cockpit ELT switch, or an electrical fault in the switch's circuit. The transmissions were received by Cospas-Sarsat's then-experimental MEOSAR system, and subsequent data collection and analyses by the Cospas-Sarsat Secretariat and engineers at France's Centre national d'études spatiales (CNES) were successfully used to calculate the likely point of impact of the flight in the Mediterranean Sea.

Aviation expert David Learmount of Flight International suggested that an electrical fire could have started in the aircraft's avionics compartment and that the aircrew may have been too distracted to communicate their distress to air traffic control.

On 22 May, the French television station M6 reported that, contrary to official statements, one of the pilots told Cairo air traffic control about smoke in the cabin, and decided to make an emergency descent. Later that day, the report was dismissed as false by the Egyptian Civil Aviation Ministry.

On 24 May, a forensics official from Egypt's investigative team said that the remains of the victims indicated an explosion on board. The head of forensics denied the claim.

At the beginning of June, France 3 and Le Parisien reported that the aircraft had performed three emergency landings in the hours before the crash—at Asmara, Tunis, and Cairo—followed by technical inspections, after ACARS messages "signalled anomalies on board shortly after takeoff from three airports". On 2 June, Safwat Musallam, EgyptAir's chairman, denied the report.

With investigations into the crash ongoing, Egyptian officials announced on 29 June that data recovered from the flight data recorder, as well as recovered wreckage from the plane, indicated that smoke had occurred on the aircraft, which matched previous information relayed by the plane's ACARS. Egyptian Civil Aviation Ministry experts have suggested that wreckage from the front section indicates high temperature combustion. Also, the data showed that the flight data recorder recorded the smoke and fault alarms at the same moment that the aircraft's ACARS relayed messages about them to the ground station, and that the data recorder stopped recording at an altitude of 37000 ft above sea level. Media reported that data from the cockpit voice recorder indicated one of the pilots had tried to extinguish the fire in the cockpit before the airplane crashed. After these reports were released, the Egyptian Civil Aviation Authority urged "media to be cautious while issuing press releases about the accident and to only rely on official reports issued by the committee itself." On 16 July the committee confirmed that the cockpit voice recording mentioned "the existence of a fire".

On 22 July, investigators privately suggested that the aircraft might have broken up in mid-air.

In August 2016, French foreign minister Jean-Marc Ayrault criticized the fact that no further explanation for the reasons behind the crash had been given. In December 2016, Egyptian officials said traces of explosives were found on the bodies, hinting to a possible terrorism attack. In May 2017, the BEA led by France conducted their own investigation, ultimately dismissing the explosives claim as they were unable to find any explosive residue, and no terrorist organization claimed responsibility for the crash.

On 17 September 2016, Reuters relayed a 16 September report from the French news outlet Le Figaro that French forensic investigators visiting Cairo noted traces of the explosive TNT on the aircraft debris. According to Le Figaros source, Egypt proposed a joint report with France announcing the discovery of evidence of an explosive, but France declined, alleging that Egyptian judicial authorities did not allow the French investigators "to carry out an adequate inspection to determine how the traces could have got there".

A manslaughter investigation was started in France in June 2016; in April 2019, a report commissioned as part of the investigation stated the aircraft was not airworthy and should have never taken off: recurring defects had not been reported by the crews, including alerts reporting potential fire hazards.

On 15 December 2016 Egyptian investigators announced that traces of explosives had been found on the victims; a source close to the French investigation expressed doubts about these findings. On 13 January 2017, French newspaper Le Parisien published an article claiming that unspecified "French authorities" believed the aircraft might have been brought down by a cockpit fire caused by an overheating phone battery; it noted parallels between the position where the co-pilot had stowed his iPad and iPhone 6S and data that suggested an accidental fire on the right-hand side of the flight deck, next to the co-pilot.

On 7 May 2017, French officials stated that no traces of explosives had been found on the bodies of the victims.

On 6 July 2018, France's BEA stated that the most likely hypothesis was a fire in the cockpit that spread rapidly.

In April 2022, French investigators stated, in a report submitted to the Court of Appeal of Paris and obtained by Corriere della Sera, that the fire was caused by a cigarette in the cockpit which burned out of control when exposed to oxygen emitted from an oxygen mask, which was improperly set to an emergency setting; smoking in the cockpit was not prohibited at that time and Egyptian pilots habitually smoked in the cockpit. A study conducted by the BEA found that "no evidence from the CVR confirms or refutes the hypothesis that people were smoking in the cockpit" and that "tests carried out do not suggest that a lit cigarette contributed to the accident sequence".

On 30 October 2024, Egypt's Civil Aviation Authority concluded in its final report that the crash was the result of an explosion in the galley area behind the cockpit. The subsequent fire rapidly propagated resulting in multiple systems failure, exacerbated by oxygen flowing inside the cockpit, as a result of the explosion, which enriched the fire and the smoke. This theory was rejected by the BEA, which concluded the fire was most likely a result of a fault in the oxygen mask. Concluding on a "[s]cenario based on presence of explosives", the BEA stated that:

French manslaughter investigation

In June 2016, Paris prosecutor's office indicated that a preliminary investigation into the accident would begin, since no evidence of any act of terrorism had been found; the office had opened a manslaughter investigation instead.

In April 2019, a report commissioned as part of the French investigation and seen by Le Parisien stated the aircraft was not airworthy. On at least four previous flights recurring defects were not reported by the crews and the aircraft was not checked according to procedure. Some twenty alerts (visual and audible) had been made by the ECAM system the day before the flight, including alerts reporting an electrical problem that could lead to a fire. Pilots instead reset circuit breakers and cleared the messages, in violation of the appropriate procedures instructed by Airbus. More alerts had been noted as far back as 1 May 2016, occurring over dozens of flights operated by the aircraft, but were ignored by the airline.

The premises of BEA had to be searched under warrant as part of the investigation to obtain these data, and that occurred in October 2018. The BEA claimed that under international aviation law they were not responsible for supplying information to French judicial investigators. While they at first denied having data-recorder data, they later explained that automatic back-ups had retained the data after the original files had been deleted.

Crews on the flights preceding the crash told the investigators that they had not encountered any problems during their respective flights. EgyptAir's CEO Ahmed Adel also rejected the French report, citing it as "misleading."

Confidential documents released in December 2019 by The Wall Street Journal stated that an oxygen leak may have been responsible for the fire, and indicated that a sound similar to a high-pressure leak was heard on the CVR before the captain declared a fire, while passengers were moving to the back of the plane.

The crash of EgyptAir Flight 804 was featured in the 2023 episode "Mystery over the Mediterranean", of the Canadian-made, internationally distributed documentary series Mayday.

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ReferencesInformational notesCitations'''

Final Report EgyptAir A320 Aircraft crash in the Mediterranean, registered SU-GCC, flight number MSR804, from Charles De-Gaulle Airport, Paris to Cairo International Airport, on 19/05/2016 - by Arab Republic of Egypt Ministry of Civil Aviation Egyptian Aircraft Accident Investigation Directorate

Oxygen fire in cockpit study - Accident to the A320 registered SU_GCC on 19 May 2016 - a safety study report by the BEA

Archived live updates (no longer updated) – The GuardianArchived live updates (no longer updated) – BBC News

EgyptAir MS 804 Paris Cairo (Alt link at Emergency Page) – EgyptAir

Statements regarding the loss of Egyptair Flight 804 – Airbus, the manufacturer of the aircraft involved

Accident to the Airbus A320, registered SU-GCC and operated by Egyptair and Accident to the Airbus A320, registered SU-GCC and operated by Egyptair, on 05/19/2016 in cruise off the Egyptian coast – the French Bureau of Investigation and Analysis for Civil Aviation Safety

Press releases – Egyptian Ministry of Civil Aviation

Disparition du vol MS804 - Le Monde''