EgyptAir Flight MS804, an Airbus A320, left Paris Charles de Gaulle Airport at 21:09 UMT (Universal Mean Time, 11:09 p.m. Paris time)[1] on May 18, 2016, bound for Cairo with 56 passengers, seven crew members and three security personnel on board. At 23:24 UMT, the plane entered Greek airspace. Air traffic controllers last spoke to the pilot at 23:48 UMT. He was in good spirits and reported no problems at that time.

According to data sent back to the airline via the aircraft’s onboard Aircraft Communications Addressing and Reporting System (ACARS) satellite reporting system, thirty eight minutes later, at 00:26 UMT, smoke was detected in a lavatory. One minute later, smoke was also reported in the avionics bay which contains the aircraft’s electronics and computers below the cockpit. Controllers tried to make contact with the plane, but the aircraft did not respond. Radar returns then showed it making a 90 degree left turn, followed, by a full circle to the right, while dropping from 37,000 to 10,000 feet. Radar contact was lost at 00:30 UMT, when the aircraft was 174 miles from the Egyptian coast.

Debris and body parts were soon found on the ocean surface near the plane’s last known location. Immediately after the event, Egypt’s civil aviation minister stated that the possibility of a terrorist attack bringing down the aircraft was stronger than technical failure. The media and political figures were quick to treat it as a terrorist act. But two months later, what is known about the fate of MS804?

Although the aircraft went down in one of the deepest parts of the Mediterranean, less than a month later a specialized deep ocean search vessel located the wreckage on the sea floor at a depth of 9,800 feet and recovered the “black boxes” (flight data recorder and cockpit voice recorder). Badly damaged, they were flown to France for repair and restoration, and were then returned to Egypt, where the accident investigation is being conducted.

A deep ocean search vessel operating under contract to the Egyptian government has recovered human remains at the crash site and delivered them to forensic doctors and prosecutors. The ship will return to the crash site to continue searching for undiscovered remains.

Egyptian officials now say that evidence found in the wreckage and data retrieved from the flight data recorder contains information consistent with the ACARS messages showing smoke in one of the lavatories and the avionics bay located under the cabin floor and behind the cockpit, where key electronics are housed. Egyptian crash investigators have also said that recovered wreckage shows signs of high temperature damage and soot. And the investigators have stated that the cockpit voice recording shows that the pilots tried to extinguish an onboard fire. The flight data recorder data, the cockpit voice recording, the ACARS satellite based reporting system data, and the physical wreckage showing heat damage are all consistent with fire and smoke in a lavatory and the avionics area. All of the forensic evidence developed and released to date points to an on-board fire of unknown origin.

In France, the Paris prosecutor’s office has opened a manslaughter investigation into the crash. The prosecutor says it is not looking into terrorism as a possible cause of the crash at this stage, and no group has claimed responsibility for it.

The investigation into the loss of EgyptAir flight 804 is far from over. Extraordinary search, recovery and investigative efforts have already yielded much relevant physical evidence and data, and there is good reason to believe that the probable cause of the accident will ultimately be determined. The investigation results underscore the importance of avoiding the speculative rush to judgment that is all too common in the immediate aftermath of air disasters, and of relying on the results of careful scientific analysis of the evidence to determine the true facts of these tragic events.