A-310's are to be inspected as well. It does seem the authorities and experts are still deciding how best to inspect for voids or delamination in the composite structure.
Excerpted from the Nov 16 New York Times:
"American Airlines said on Wednesday that it would inspect its 34 surviving Airbuses. John L. Hotard, a spokesman for the airline, said yesterday that it was still planning how to carry out the inspections. The part to be inspected most carefully is a section at the base of the tail fin that was torn apart.
"The [FAA] order is expected to cover the 91 A300's registered in this country and another 46 A310's, which are similar but shorter planes. It will give the operators about 10 days to inspect the tails.
"The shaking incident evidently followed the encounter with the wake, but the connection is not yet clear. Airplanes leave two wakes behind them, disturbances in the air that resemble horizontal tornadoes, one trailing each wingtip. The plane that crashed bumped over the first one about 28 seconds before the flight data recorder stopped working, and the second one about 8 seconds before the data ended.
"In the first seconds after clearing the second wake, "the airplane appears to be consistent with flight control inputs," said Thomas Haueter, the board's deputy director of aviation safety, meaning that the plane's performance still matched the pilot's working of the controls.
"But shortly after that second encounter with a wake vortex, the plane was shaken laterally, changing its direction suddenly and forcefully. Forces on the plane are measured in G's, with one G being equal to the normal force of gravity.
"In mere seconds, passengers felt a sudden powerful swing in one direction, and then another slightly more forceful one in the same direction. They were being hit with forces 30 or 40 percent as strong as the normal force of gravity. (In contrast, the bumps from the wake vortices were equal to only 10 percent of the force of gravity, Mr. Haueter said; he said that the 10 percent was
"the type that sloshes your drink."
"Investigators said the plane's rudder moved in concert with the swings, apparently causing the sideways movements, but Mr. Haueter said investigators were looking into whether the rudder had moved on its own or the pilots had manipulated it. Then, in the last 2.5 seconds or so that the data recorder was still working, the plane lurched wildly to the side, its left wing lowered and its nose pitched forward. The drop to the ground had begun.
"Despite witness accounts to the contrary, Mr. Haueter also said that there was no evidence of any fire in the engines before impact."
Excerpted from the Nov 16 Washington Post:
"According to information released by Blakey today, this was what happened during the last seconds before the flight data recorder stopped working:
"• The American Airlines plane moved abruptly in a way consistent with hitting wake turbulence, but was not affected in any significant way. A similar movement occurred seconds later. Again, the plane was not significantly affected. The force of the encounters were about 10 percent of the force of gravity, certainly enough for passengers to notice but not particularly
dangerous.
"• About one second after the second wake turbulence encounter, and eight seconds before the recorder cut off, the plane made a violent movement to the right, jerking passengers sideways at about 30 percent of the force of gravity. It then made an even more abrupt move to the right, affecting
passengers with about 40 percent of the force of gravity. Then it moved left at about 30 percent the force of gravity. The data show that the rudder moved abruptly at the time of each movement. "This was a very significant lateral acceleration," Blakey said.
"The board said the rudder pedals in the cockpit moved in tandem with the rudder itself. That would almost always mean that the pilots induced the movements by pushing the rudder pedals. At this point, however, investigators cannot rule out some other explanation, including an autopilot malfunction or, perhaps, events that may never have happened before. The rudder -- the movable flat plate at the rear of the vertical tail fin -- is seldom used in flight
except when an engine fails, or to keep the plane from fishtailing in turbulence or when coming out of turns.
"• At 2.5 seconds before the end of the tape, rudder data on the recorder became "unreliable," possibly because the rudder had cracked off.
"• Side pressure increased to 80 percent of the force of gravity, and the plane rolled left to 25 degrees left-wing down as the nose pitched down 30 degrees. Passengers were pushed down into their seats at twice the force of gravity. The recorder cut off at that point.
"According to accident and incident records, at least two other A300-600s have
experienced serious in-flight emergencies, one apparently crew-induced and one
caused by an autopilot malfunction.
"On May 12, 1997, an American Airlines aircraft went through a series of violent maneuvers somewhat similar to Flight 587's as it prepared to land in Miami. The safety board determined that the crew first had inadvertently allowed the plane to stall, then mishandled the plane's recovery. The aircraft landed safely at West Palm Beach, Fla., but seven passengers and crew members
were injured.
"On May 17, 1999, an American Airlines plane experienced uncommanded rudder movements. The crew was unable to move the rudder with the foot pedals but used other controls to make the landing. The problem was caused by the autopilot."
[ 16 November 2001: Message edited by: SaturnV ]