An American Airlines pilot is likely to be blamed by government investigators for causing the crash of Flight 587, which plunged into a Queens neighborhood on Nov. 12, 2001, killing all on board and five people on the ground, according to sources familiar with the probe, but aircraft design is also likely to be cited as a contributing factor.

The National Transportation Safety Board will today hear the findings of its staff investigators and may vote as early as today on a final determination of the probable cause of the accident. It is also expected to discuss whether there was adequate communication about safety issues related to the aircraft. The crash attracted global attention because it occurred two months after terrorists attacked New York and the Pentagon.

The Airbus A300-600, heading for the Dominican Republic, encountered wake turbulence moments after takeoff from John F. Kennedy International Airport and crashed seconds later into the Rockaway Beach neighborhood of Queens, killing 260 aboard and five people on the ground. Investigators determined that the tail fell off the plane shortly before it went down.

American has waged an aggressive campaign in recent weeks to convince the NTSB board, its staff and the agency's investigative staff that the plane's manufacturer hid damning evidence of previous incidents involving the rudder of the same aircraft model. American's last-minute lobbying has succeeded in raising fresh doubts among some board members about whether American, Airbus SAS and the board communicated effectively about safe operation of the A300-600's rudder, according to sources familiar with the investigation who spoke on condition of anonymity because the findings were not official yet.

These sources believe the NTSB staff will still point to the pilot of Flight 587 and his back-and-forth pressure on the rudder foot pedals as the reason the tail came off and the plane crashed. The sources also said the sensitivity of the aircraft's rudder pedals is also likely to be cited as a contributing factor in the crash.

The board's decision could be used in lawsuits filed by relatives of those who died in the crash. American said 70 percent of the suits have been settled.

"It's easy to focus on what started the sequence of events" that led to the crash of Flight 587, said American spokesman Bruce Hicks. "But it ignores the root cause, which is system safety. . . . Airbus never told safety investigators about previous incidents."

As part of its evidence, American pointed to internal Airbus memos written after a nonfatal accident involving another American plane, also an Airbus A300-600. The memos from June 1997 show urgent concern among Airbus managers that the aircraft's rudder had sustained high loads, or stresses, after American Airlines Flight 903 to Miami stalled during a flight and the pilot used the rudder to try to recover. Internally, Airbus recommended that the plane be inspected "as soon as possible," but American claims that it was never informed of the memos until after Flight 587 crashed.

Airbus denied that it had been less than forthcoming about problems with its rudder. The European manufacturer provided several documents to American, including one signed four years before the crash by Airbus and rival manufacturers Boeing Co., McDonnell Douglas and the Federal Aviation Administration that jointly raised concerns about the way American trained pilots to use the rudder. The document indicated American taught its pilots to be aggressive in their use of the rudder, which could result in a "rapid loss of controlled flight."

The letter, dated Aug. 20, 1997, said, "The excessive emphasis on the superior effectiveness of the rudder for roll control . . . is a concern."

Airbus said its letter clearly warns American to correct its training, which the carrier said it did in updated training videos distributed to pilots. "I would agree that our communication to American and others, had it been taken to heart, might have indeed avoided this accident," said Clay McConnell, an Airbus spokesman. "I see no evidence that American pilots were untrained from their dangerous behavior."

Airbus said that the pilot's aggressive back-and-forth use of the rudder right after Flight 587 encountered wake turbulence led the tail of the aircraft to come off.

During the crash investigation, the NTSB issued a recommendation for Airbus to fix another component of its rudder on the A300-600 fleet, raising concerns among pilots about rudder performance.

The crash, pilots say, raised alarms because it involved a basic aircraft part that pilots do not use very much. The rudder, the flap on the vertical tail, moves right and left to help pilots land in a crosswind. It is also used to maneuver the airplane on the ground while taxiing.

"I don't think most pilots knew as much about rudder movement and the effects on the airplane even at low speeds," said Terry McVenes, executive air safety vice chairman at the Air Line Pilots Association, which represents pilots at several major carriers but not those at American.

American said it has seen a new opportunity to convince the board of its view because four of the five NTSB members have joined since the crash.

On Nov. 12, 2001, American Airlines Flight 587, heading for the Dominican Republic, crashed shortly after takeoff, killing 260 aboard and five people on the ground in Queens.