EgyptAir pilots tried to put out a fire on board a plane that crashed into the Mediterranean Sea in May, investigators have said after analysing a recovered cockpit voice recorder.

The Egyptian-led investigative committee said on Tuesday, though, that the experts needed more time to analyse the information gathered before they could reach "very basic conclusions".

The recordings were consistent with data previously recovered from the wreckage that showed heat, fire, and smoke around a bathroom and the avionics area - the part of a plane that houses electronic equipment.

The crash killed all 66 people on board. The flight, which was en route from Paris to Cairo, made no distress call, and no armed group has claimed to have brought the it down, deepening the mystery around its fate.

READ MORE: Timeline - major air disasters

Oliver McGee, an aviation specialist, told Al Jazeera the new evidence could explain why the pilots did not raise the alarm.

"Fire on board is a very critical event," McGee said. "It is very difficult for pilots to aviate, to navigate, much less communicate when they are also serving as firefighters on the plane." 

The Egyptian investigators said no theories - including an attack - were being ruled out, especially since it was rare for such a fire to break out so suddenly.

Deep ocean search

EgyptAir Flight 804 disappeared from radar about 2:45am local time on May 19 between the Greek island of Crete and the Egyptian coast.

Radar data showed the aircraft had been cruising normally in clear skies before it turned 90 degrees left, then a full 360 degrees to the right as it plummeted from 11,582 metres to 4,572 metres.

It disappeared when it was at an altitude of about 3,048 metres.

Deep ocean search teams have been recovering human remains and bringing them to Egypt's port city of Alexandria.

French authorities opened a manslaughter inquiry late last month, but said there was no evidence so far to link the crash to "terrorism".

 

Source: Al Jazeera and agencies