Still no word on the cause.
Donald Carty, chairman of American Airlines, said so far he had "absolutely no indications" about what caused the tragedy.
"Today's news comes at a difficult time for the nation, a difficult time for the airline industry and a very difficult time for American Airlines, " he said.
"Given the changed world that we live in today it will be as important as it ever has been to quickly determine the cause of the accident."
The US Government said it was still not clear whether terrorism had caused the crash or not, but that no credible threat had been received before the plane had taken off.
Mary Blakey, of the National Transportation Safety Board (NTSB), said:
"All the information we have currently is that this is an accident, but we are co-ordinating with the FBI."
Investigators recovered the cockpit voice recorder, one of the two black boxes from the twin-engine jet.
George Black, of the NTSB, said the quality of the recording was good, and that the co-pilot was at the controls, which was not unusual.
Blakey said initially the recording revealed nothing "to indicate a problem that is not associated with an accident".
An American Airlines spokesman said the aircraft had a maintenance check only the day before the crash.
Its last major maintenance overhaul had been on December 9, 1999 and the next was due in July 2002.
Air crash investigators were today continuing to examine the flight's black boxes and the debris strewn across the suburban neighbourhood in Queens.
Last night, as darkness fell in New York, several hundred people had worked under the glare of lights, formed bucket brigades and separated debris into gruesome piles of luggage, plane parts and human remains.