I am not sure you understand what is exactly being talked about here.
At 35,000 feet above the Caribbean, Air Transat flight 961 was heading home to Quebec with 270 passengers and crew. At 3.45 pm last Sunday, the pilot noticed something very unusual. His Airbus A310's rudder - a structure 28 feet high - had fallen off and tumbled into the sea.
One former Airbus pilot, who now flies Boeings for a major US airline, told The Observer : 'This just isn't supposed to happen. No one I know has ever seen an airliner's rudder disintegrate like that. It raises worrying questions about the materials and build of the aircraft, and about its maintenance and inspection regime. We have to ask as things stand, would evidence of this type of deterioration ever be noticed before an incident like this in the air?'
He and his colleagues also believe that what happened may shed new light on a previous disaster. In November 2001, 265 people died when American Airlines flight 587, an Airbus A300 model which is almost identical to the A310, crashed shortly after take-off from JFK airport in New York. According to the official report into the crash, the immediate cause was the loss of the plane's rudder and tailfin, though this was blamed on an error by the pilots.
There have been other non-fatal incidents. One came in 2002 when a FedEx A300 freight pilot complained about strange 'uncommanded inputs' - rudder movements which the plane was making without his moving his control pedals. In FedEx's own test on the rudder on the ground, engineers claimed its 'acuators' - the hydraulic system which causes the rudder to move - tore a large hole around its hinges, in exactly the spot where the rudders of both flight 961 and flight 587 parted company from the rest of the aircraft.
This leads to the vertical fin (the tail), failing. Which leads to it coming off, and the plane losing all controllability. Which is exactly what happened.
But Boeing is learning how hard composites can be to analyze effectively and build economically for commercial jet structures. The company has had to delay the 787’s introduction because elements of the composite-made wing box–the major structure inside each wing–buckled in stress tests.
The issue with composites isn’t that they aren’t strong; it’s that they are so internally complex. They consist of layers oriented in different directions; those layers, in turn, are made of individual fibers that may vary somewhat in composition. This makes it difficult for engineers to accurately mimic their performance in computer models for premanufacture testing.
“Composite materials are more difficult to analyze than simple homogenous metals,” says John Hansman, director of the International Center for Air Transportation, at MIT. “You generally don’t model every fiber in the structure, so you come up with models that have simplifications.”
reply to post by luxordelphi
All Airbus aircraft have fly by wire.
Just wondering if you've heard anything about why the fuselage panel fell off in flight and what the fix is going to be for that
reply to post by luxordelphi
Because they didn't "just fall off". They never fell off, at any point in testing, be it on the ground, or in flight (obviously).
Again, apparently you're confused. They had a problem with the center wing box that required redesign. And a problem with some fasteners that had to be replaced. At no point in time, EVER, did the wings "fall off".edit on 10/24/2013 by Zaphod58 because: (no reason given)
You are speaking nonsense and out of your league honestly.
The wing box was tweaked, way prior to the certification of airworthiness of the frame so it holds no bearing to your argument. The problem was identified long before it was put into the market.
reply to post by luxordelphi
No fly-by-wire is a direct replacement of old hydraulic systems; not the automation of them.
No the problem was with the training that was given and pilot error. It is clearly documented and confirmed. Pilots were being taught to hit the rudders hard during wake-turbulence and particularly, the First Officer was an offender of utilizing that method. They failed to recognize the limits, capabilities and characteristics of the Airbus 300 in their training and it lead to a fatal accident. Nothing fishy at all.edit on 24-10-2013 by ownbestenemy because: (no reason given)
The rudder control system on the A300-600 is conventional for a large transport airplane in that the rudder is actuated hydraulically in response to pilot inputs via foot pedals. The rudder is primarily intended to provide control during engine-out and crosswind situations. In addition to pedal inputs, the rudder can be moved by the rudder trim actuator, the yaw damper actuator, and the yaw autopilot actuator. A command from any of these sources is transmitted through a series of linkages (pushrods, bell cranks, a tension regulator, and cables) through three hydraulically powered servo controls which physically move the rudder.
A rudder travel limiter provides a variable stop that limits rudder travel as a function of airspeed.
The A300-600 vertical stabilizer and rudder are constructed of composite materials, primarily carbon or glass fibers in a polymer resin. These carbon reinforced plastics (CFRP) and glass reinforced plastics (GFRP) are pre-manufactured in sheets, and multiple sheets, or plies, are then stacked in a mold and cured under heat and pressure to form a solid structure. The plies may be specifically oriented to one another to enhance strength characteristics. The stiffness and strength are dependent on the number of plies and the orientation of the fibers in the plies.