EgyptAir flight MS804 may have suffered an on-board fire just moments before the aircraft plunged off radar screens, according to an aviation industry publication.
Warning messages sent automatically by the Airbus A320’s computer systems show smoke was detected in a lavatory close to the cockpit.
The messages were apparently sent to ground stations shortly after the plane entered Egyptian airspace on Thursday. The communications also seem to indicate a problem with the controls and computers, critical to controlling the plane.
Sky News has obtained a screen grab of the data, believed to be from EgyptAir Operations Centre’s computer. It has time stamps that match the approximate time the aircraft disappeared.
However, EgyptAir, Airbus and Egyptian officials have not yet commented on the details.
Simon Hradecky of The Aviation Herald, a website that covers the aviation industry, told Sky News what the series of messages suggests.
He said: “The window sensors are all temperature sensors.
“Their activation suggests they went over-temperature – for whatever reason.
“So the right hand sliding window is at the start of the whole sequence indicating that the window became too hot – and this is why pilot discussions more and more focus on the right hand side of the cockpit.
“Then the lavatory smoke alert comes.
“The ATA Code is not completely known, it probably identifies which of the lavatories was affected. Everybody right now assumes it was the forward lavatory right behind the cockpit wall.
“Then the avionics smoke comes active, indicating the avionics bay, the room below the cockpit with all the aircraft electronics and all its computers, contained smoke.
“And now the right hand fixed window comes active (which is forward of the sliding window and better exposed to the oncoming air) two minutes after the start of the sequence.
“Then the systems start to crumble, all of which are in the avionics bay. So one can see how the heat/fire spread and affected the systems, and that pattern makes sense.
“Many pilots assume that there was a fire in the avionics bay just below the cockpit floor.”
He added: “The smoke/fire was the first event in the crash sequence that started the crash sequence. What then happened is up to speculation until we know the contents of the cockpit voice recorder.
“However, the 90 degrees turn left is required procedure to get off the airway for an emergency descent (in order to not descend into another aircraft).
“The 360 degrees turn, as described by the Greek Defence Minister, is a good pilot manoeuvre to increase drag and thus accelerate the descent.
“In case of a catastrophic fire pilots will try to ditch the aircraft (if over water), and it would appear plausible that this is what happened.”
Experts say answers will only come with an examination of the wreckage and the plane’s cockpit voice and flight data recorders.
Egyptian authorities say they believe terrorism is a more likely explanation than equipment failure.