A sudden, catastrophic event at 37,000ft is being seen as the likely cause of the crash of EgyptAir flight MS804.
The aircraft plunged into the Mediterranean killing all 66 passengers and crew while flying from Paris to Cairo early last Thursday.
It has now emerged that seven alerts transmitted automatically from the Airbus A320 to its home base reported smoke, cockpit window damage and loss of control in the forward fuselage around the flight deck.
The French Bureau of Investigations and Analysis, which is taking part in an Egyptian-led inquiry, has refused to rule anything out amid suggestions that there was an explosion on board.
“These are not messages that enable us to interpret anything,” a spokesman said. “If there is smoke, it means that there is potentially a fire somewhere, but it does not tell us where the fire is, and it does not help us establish whether it is something criminal or whether it is technical.”
The latest developments came as Egypt deployed a robot submarine to search for the black box flight data recorders of the missing aircraft.
President Abdul Fattah al-Sisi said there was “no particular theory we can affirm right now” for what caused flight MS804 to crash.
Egypt’s civil aviation minister has said the possibility of a terror attack was stronger than technical failure, but Sisi said establishing the cause could take a long time, adding “all scenarios are possible,” the BBC reported.