The flight from Paris to Cairo plunged into the Mediterranean Sea on 19 May, killing all 66 people on board.
Automated electronic messages sent by the plane had shown that smoke detectors went off in a toilet and in the avionics area below the cockpit, minutes before the plane disappeared.
The recorded data are consistent with those messages, investigators said.
The second black box, the cockpit recorder, is still being repaired in Paris.
The Egyptian investigation committee also said that part of the front section of the aircraft's wreckage "showed sign of high temperature damage" and soot.
No distress call was made from the plane prior to the crash. The cause remains unknown.
What we know
- EgyptAir Flight MS804 vanished over the eastern Mediterranean early on Thursday 19 May with 66 passengers and crew on board
- Some surface debris was found 290km (180 miles) north of the Egyptian city of Alexandria
- Wreckage was subsequently found in several locations at a depth of about 3,000m (9,800ft)
- Signals from the plane indicated that smoke was detected in the toilet and in the avionics area below the cockpit
- Aircraft made a 90-degree left turn followed by a 360-degree turn to the right before vanishing off radar