AirWillie6475 From United States of America, joined Jan 2005, 2448 posts, RR: 1
Reply 3, posted (9 years 5 months 3 days 9 hours ago) and read 2820 times:
Mercifully, the crew was able to turn the plane around, and by steering it with their wing and tail flaps managed to land at their point of departure in Varadero, Cuba, without loss of life.
How else would you steer a plane?
I hope FedEx pays close attention to thier airbuses during maintenance. I have heard from an expert that the crash of AA was likely caused by the pilot. Something that always bothers me about Airbus aircraft is that the tail in every single type always looks smaller in proportion to the fuselage. I always wonder if they are able to take extreme side loads.
Arrow From Canada, joined Jun 2002, 2676 posts, RR: 2
Reply 4, posted (9 years 5 months 3 days 7 hours ago) and read 2754 times:
"Something that always bothers me about Airbus aircraft is that the tail in every single type always looks smaller in proportion to the fuselage."
Not exactly a scientific observation, and given that thousands of Airbuses continue to fly safely all over the world, a little overblown.
Whatever the cause of the Airbus rudder problem, it shouldn't be a reason for Boeing afficionados to gloat. I seem to recall some nasty 737 crashes that were ultimately tied to a rudder problem. Despite that, I won't hesitate to get on a 737, and I won't hesitate to get on an Airbus either.
Never let the facts get in the way of a good story.
I find it amazing that the A300/310, and the 737 have so many issues with the rudder. Rudder movement limiters seem to be a problem for both aircraft, and the A300/310 seems to suffer from over sensitivity on the rudder FBW system.
Quoting AirWillie6475 (Reply 3): Something that always bothers me about Airbus aircraft is that the tail in every single type always looks smaller in proportion to the fuselage. I always wonder if they are able to take extreme side loads.
the longer the aircraft, the smaller the tail needs to be relavite to the fuselage diameter. However it is clear that tails on the A300/310 are not designed to withstand high loads. I would assume that this problem and the over sensitity of the rudder FBW system has been fixed in subsequent aircraft.
Mika From Sweden, joined Jul 2000, 2880 posts, RR: 4
Reply 9, posted (9 years 5 months 3 days 5 hours ago) and read 2660 times:
Something that always bothers me about Airbus aircraft is that the tail in every single type always looks smaller in proportion to the fuselage. I always wonder if they are able to take extreme side loads.
If you're refering to the AA crash then i can say that it was the vertical stabilizer holding points that failed and not the vertical stab or rudder itself. Had the Vertical stab been any bigger it would have putten more load on the fittings and subsequently making it fail even easier. All this according to the laws of physics. Having an undersized/oversized vertical stab wouldnt make or break any airliner, only decrease or increase its yawing capabilities.
Do your homework before posting blunt remarks like this.
Astuteman From United Kingdom, joined Jan 2005, 9997 posts, RR: 96
Reply 10, posted (9 years 5 months 3 days 5 hours ago) and read 2655 times:
Quoting Iwok (Reply 6): However it is clear that tails on the A300/310 are not designed to withstand high loads
Whatever your definition of high loads, the tail on the AA A300 at JFK not only sustained much greater loads than it was designed for, but the design (by definition) exceeded the requirements for certification by the FAA.
NTSB quoted a combination of pilot error/pilot training/A300 rudder pedal sensitivity/Airbus guidance information - in fact virtually anything except an insufficiently strong tail.
So I would respectfully suggest that it is anything but clear that the tails on A300's are not designed to withstand high loads. "Certifiable" nonsense, I would say.
Broke From United States of America, joined Apr 2002, 1322 posts, RR: 3
Reply 12, posted (9 years 5 months 2 days 22 hours ago) and read 2547 times:
One of the things that upsets me about aviation reporting is the level of ignorance of things aeronautical by many of the authors. When they write an article that contains inaccuracies, they propagate their ignorance throughout the general public who use the press as a source of information.
A few terms that should be known when referring to the American Airlines tragedy and the Air Transat incident.
The American Airlines A300-600 lost its vertical stabilizer, not its tail. The failure occurred at the fuselage attach points at the base of the vertical stabilizer. The purpose of the vertical stabilizer to provide longitudinal stability to the airplane. The rudder is the flight control that is attached to the trailing edge of the vertical stabilizer and the rudder's purpose is to provide control in the yaw axis of the airplane.
The Air Transat A310 lost its rudder and happily there was sufficient stability and control remaining to allow for a safe landing. It is highly likely that the Air Transat crew did not know they had lost the rudder. They knew they had some sort of structural and control problem, but since you can't see the empennage (another word!!) from inside the airplane they could not identify the magnitude of their problem until they landed and got off the airplane.
Right now, it is impossible to determine if the two failures are related or are independent of each other. I suspect that they are two independent failures.
The lower spar of the rudder was still on the A310 after it landed which would lead me to believe that the rudder failure began at or near the top of the rudder and progressed downward rapidly.
Oh yes, the empennage. The enpennage (or tail section) of an airplane includes the vertical stabilizer and rudder; the horizontal stabilizers (2 each) with (usually, but not always) an elevator attached to each horizontal stabilizer trailing edge; and the rear section of the fuselage to which all 3 stabilizers are attached.
On the Airbus airplanes (among others) the horizontal stabilizers can be pivoted over a relatively short range at the fuselage and the elevators are hinged at the horizontal stabilizers to provide stability and control in the pitch axis. In fact, the only large jet transports that do not have trimmable stabilizers (that I know of) are the Antonov AN-124 and AN-225. I would think that this would reduce the stability of these airplanes at higher Mach numbers, restricting their cruise Mach number in the lower .7 range; but I don't know that for certain.
Starlionblue From Greenland, joined Feb 2004, 17015 posts, RR: 67
Reply 13, posted (9 years 5 months 2 days 21 hours ago) and read 2486 times:
Quoting Ktachiya (Reply 7): Quoting AirWillie6475 (Reply 3):
crash of AA was likely caused by the pilot
Are you talking about the one at JFK? Where did you get that?
The final report came out quite a few months ago and it was quite clear that the fault was mostly the flying pilot's. As has been said, the fin withstood forces well above certification loads. Any aircraft can be broken by the pilots, with the possible exception of the FBW Airbi with envelope protection active. But I'm sure a way could be found to break them too.
"There are no stupid questions, but there are a lot of inquisitive idiots."
Bennett123 From United Kingdom, joined Aug 2004, 7525 posts, RR: 3
Reply 15, posted (9 years 5 months 2 days 13 hours ago) and read 2349 times:
Firstly, IMO when a plane falls apart you get a hole in the ground.
Secondly, they say that the rudder disintergrated, i.e. broke into many parts.
My understanding is that it has not been recovered yet. In that case, no one knows if it separated in one piece or disintergrated.
Thirdly, Prof Williams's comments would be more valid if the Stabiliser had failed below the certified limit. My understanding is that it failed at nearly double the certified limit.
Finally, I do not recall the NTSB saying that the A300 controls were flawed. I would have expected an AD to be issued if that was there conclusion.
Iwok From Sweden, joined Jan 2005, 1108 posts, RR: 0
Reply 19, posted (9 years 5 months 2 days 4 hours ago) and read 2200 times:
Quoting Leskova (Reply 8): The A300/310 does not have a FBW rudder... or, for that much, FBW anything...
Les, please excuse my apparent ignorance. I though that the rubber was FBW controlled based on the updates that I was reading on the NTSB. While the investigation was underway, I read each and every update that was released, but for some reason, they are not longer available at the website. If you go to http://www.ntsb.gov/events/2001/AA587/default.htm you will see a bunch of links which are no longer valid.
Anyway, one of the reports that I read stated that the sensitity of the rudder controls on the A300 changes with air speed. In the A300 case, as the plane speed increases, the force feedback on the rudder pedals decreases (which is opposite to what I would have thought, but I am not an aircraft controls engineer...). What this means is that as the airspeed increases, less force is required on the rudder pedals to affect the same deflection in the rudder. "...This can make the aircraft more sensitive to a piloting phenomenon called adverse Aircraft Pilot Coupling (APC.)"
Hence I concluded that this inversely proportional force feedback rudder control system was FBW. Please excuse my mistake.
Quoting Astuteman (Reply 10): NTSB quoted a combination of pilot error/pilot training/A300 rudder pedal sensitivity/Airbus guidance information - in fact virtually anything except an insufficiently strong tail.
Astute, yes I agree. As I stated above, I have not been able to open the previous reports on the NTSB website, to back up my earlier statement. I thought that the article in www.usread.com was intersting because it did highlight some of these ommisions from the final NTSB report. You are correct in that the report does indicate that the tail did see loads over its design limit... I find that the following quote is interesting (also from www.usread.com)
"....that there was a problem with the Most experts who believe tail separation was the cause of AA 587’s crash agree that had the NTSB and FAA been informed by Airbus about the role that rudder reversals and the faulty RTLU (Rudder Travel Limiting Unit) had on the extreme loads placed on AA 903's tail, the crash of AA 587 could have been prevented."
If you recall, there was a major issue with 737 RTLU's that had to be fixed.
Quoting Starlionblue (Reply 13): The final report came out quite a few months ago and it was quite clear that the fault was mostly the flying pilot's.
Starlionblue, I have read the report, and it is a little different from the updates that were provided during the investigation.
Based on my reading over the past few years on the 587 crash, I believe that the rudder sensitivity issue in conjunction with the training given by AA are to blame for the crash. To me, the NTSB report seems to place a lot of blame on the pilot and very little on AA and Airbus. Remember, both AA and Airbus will use the NTSB document in court, to reduce how much they will have to pay out, and so it makes sense for them to put most of the blame on a dead pilot.