OFFICIALS THEORIZE A PILOT CAUSED EGYPTAIR'S DEADLY DIVE.

Byline: David Johnston and Matthew L. Wald The New York Times

A detailed analysis of the voice and data recorders aboard EgyptAir Flight 990 indicates that a crew member, possibly a relief pilot, seized the controls of the passenger jet and forced the plane into a steep dive toward the Atlantic Ocean, government officials said Tuesday.

Based on the new information, investigators also theorize that the veteran captain of the Boeing 767, Ahmed al-Habashi, who had briefly left the cockpit and returned, struggled in vain to regain control of the aircraft after the other pilot calmly uttered an Arabic expression about putting his trust in God, switched off the autopilot and pitched the Boeing 767 into the high-speed plunge.

The officials said the relief pilot at the center of the inquiry was Gamil al-Batouti, a 59-year-old veteran EgyptAir employee and former Air Force aviator. Batouti was not assigned to fly the plane at the time of the crash, but the officials said they believe he is the man in the co-pilot's seat whose remark about God can be heard seconds before the plane began its fatal descent.

The scheduled co-pilot was aboard the flight, but was apparently not in the cockpit at time of the crash and his whereabouts on the plane were unknown.

EgyptAir representatives familiar with the voice of the airline's crews listened to the cockpit voice recorder and identified the voice of Batouti, the officials said.

But the officials cautioned that they had no other verification of Batouti's voice and, that there were four pilots aboard the plane who could have flown it. The officials also warned that further analysis of the information might lead them to different conclusions.

The increasing likelihood that the relief pilot, or another EgyptAir crew member, deliberately brought down the aircraft led the authorities Tuesday to prepare to transfer the inquiry to the FBI.

But the National Transportation Safety Board, which has had authority over the inquiry, decided Tuesday to keep its jurisdiction, in response to Egyptian complaints that the American authorities were moving too quickly to blame a crew member for the crash.

As federal authorities reconstructed the final horrifying seconds of the flight, air safety and law enforcement officials provided a clearer account of what might have happened on the Oct. 31 flight, which seemed routine as the big jet left Kennedy International Airport bound for Cairo and reached its 33,000-foot cruising altitude.

Then, just after 1:49 a.m., something went wrong.

The unusual events began seconds after the pilot, Habashi, briefly left the cockpit, the officials said. The departure was inferred by authorities from the sound of the cockpit door opening and closing. They believe that Habashi left Batouti alone in the cockpit because they have picked up no other voices.

When he was alone, the other pilot repeated quietly and calmly, ``Tawakilt ala Allah,'' the officials said.

At about this time someone shut off the autopilot. The officials said that the voice recorder's cockpit microphones picked up Habashi saying in Arabic, ``What's going on?'' or ``Let's fix this.''

Seconds later the plane began its steep descent, from 33,000 feet to less than 17,000 feet. It is unclear at exactly what point in the flight that the two men spoke, but the flight data recorder showed that eight seconds after the autopilot was disconnected, the plane began its plunge toward the sea.

During the dive, the two parts of the tail that control whether the plane dives or climbs moved in an unusual fashion. Although in normal flight operations the two parts move in tandem, investigators said they were initially baffled by the movement of the left and right parts of the tail in opposite directions.

The officials now hypothesize that one pilot may have been desperately trying to pull out of the dive while the other pilot was forcing the plane's controls down. There is no indication that the two men in the cockpit engaged in a physical struggle with each other.

Near the bottom of the dive, someone turned the engine control levers to the cutoff position - a possible but not definitive clue that a struggle for control of the plane ended when one man shut down the engines.

Subsequently, the plane regained altitude, climbing several thousand feet until it stalled, reaching a speed too slow to remain airborne. The aircraft apparently broke and fell into the Atlantic, killing all 217 people on board.

Tuesday, it was unclear whether investigators had gleaned most of what they expected to extract from the voice and data recorders. They initially said there was nothing on the tape to indicate a criminal act. But in more thorough analyses and evaluations by Arabic speakers, their conclusions have changed significantly. And some officials cautioned that further analysis might lead them to still different theories about the cause of the crash.

Aviation safety officials said that with many questions unanswered, recovery operations will continue at the site of the crash, 60 miles south of Nantucket, as American and Egyptian investigators compile highly detailed biographical accounts of the EgyptAir crew members, all of whom had recently undergone routine medical and psychological evaluations.

CAPTION(S):

2 photos, box

Photo: (1) al-Batouti

(2) al-Habashi

Box: Final moments of flight 990