Jump to content
Sign in to follow this  
CF104

What made an Airbus rudder snap in mid-air?

Recommended Posts

>All modern aircraft are safe. It's the people that repair>them or the people that fly them that can make them unsafe.As one who maintains modern aircraft I find your statement uneducated, uninformed, narrowminded and furthermore rude. By your own admission, you would consider(assume) the designers infalable? You would also consider(assume) the structures and materials 100% safe? It is remarks like yours that paint the industry in a bad light. Lets give these stupid people (maintainers and pilots) a "perfect aircraft" and see if they can handle it. If they can't then we'll blame it all on them... ha ha! You might want to think twice before labelling certain groups as the main cause of aircraft accidents. Regards,JohnBoeing 727/737 & Lockheed C-130/L-100 Mechanichttp://www.precisionmanuals.com/images/forum/ng_driver.jpg

Share this post


Link to post

>>All modern aircraft are safe. It's the people that repair>>them or the people that fly them that can make them unsafe.>>As one who maintains modern aircraft I find your statement>uneducated, uninformed, narrowminded and furthermore rude. By>your own admission, you would consider(assume) the designers>infalable? You would also consider(assume) the structures and>materials 100% safe? It is remarks like yours that paint the>industry in a bad light. Lets give these stupid people>(maintainers and pilots) a "perfect aircraft" and see if they>can handle it. If they can't then we'll blame it all on>them... ha ha! You might want to think twice before labelling>certain groups as the main cause of aircraft accidents. >Get out of bed the wrong side did we, John?Tell me, what percentage of modern aircraft accidents were caused by errors in maintenance. I understand that Boeing themselves have mentioned that the figure is around 15%. Someone correct me if this figure is way out. Then tell me what percentage of modern accidents were caused by pilot error? I believe the figure is around 85% of all aviation accidents but others may have have better information. Finally, tell me what percentage of accidents are caused solely by aircraft design. I would hazard to guess that the third cause is very small compared to the other two.

Share this post


Link to post

Victor,And exactly what experience and training do you have in the industry? Have you had human factors training? Do you know that most accidents are caused by a chain events in which one may be a shortcoming in design or materials.I will admit that the majority of accidents are human error but what got me is your comment that "ALL" modern aircraft are safe, implying that every single accident is caused by maintenance or flight crew.JohnBoeing 727/737 & Lockheed C-130/L-100 Mechanichttp://www.precisionmanuals.com/images/forum/ng_driver.jpg

Share this post


Link to post

Hi Victor...there are absolutely no absolutes in aviation. bt

Share this post


Link to post
Guest VApilot2004

Yup saw that just an hour ago - About time Airbus gets on the ball with this. This may help clarify the muddied findings by the NTSB on the AA587 tragedy. There is clearly a problem with the rudder design and pilot interaction - something internal memos at Airbus Industrie have said before - but kept secret.Interestingly, FedEx's maintenance engineers, on investigating a recent Un-Commanded rudder incident on an A300, discovered the actuators tore holes in the composite rudder in exactly the same places as both the ATA Airbus and the AA587 Airbus, of course the AA587's entire composite fin snapped off mid-flight.One of the problems (in addition to the single-spar Vertical Fin design mentioned here before) with the Airbus tail/rudder system is the forces required by the pilot to initiate and continue a simple rudder movement. According to American Airlines' own maintenance engineer in the NTSB report of the AA587 tragedy, the pilot used only 10 POUNDS of force with a one and one quarter inch (1.25") depression of the rudder pedals to cause a FULL Rudder deflection by the system. In addition to that startling fact is that the Aircraft was traveling well below VA - manuevering speed - which according to every pilot's teachings - if you are below that speed the aircraft is safe to withstand full control inputs with no damage. There's a gap between sound flight training and Airbus design principles - not Airbus' fault per se - just something that was not considered before the loss of Flight 587.Anyway,Airbus is showing some wisdom here - let's see where it leads.

Share this post


Link to post

>There is clearly a problem with the rudder design and pilot>interaction - something internal memos at Airbus Industrie>have said before - but kept secret.>Secret memos? And what evidence do you have of this?>Interestingly, FedEx's maintenance engineers, on investigating>a recent Un-Commanded rudder incident on an A300, discovered>the actuators tore holes in the composite rudder in exactly>the same places as both the ATA Airbus and the AA587 Airbus,>of course the AA587's entire composite fin snapped off>mid-flight.>That would be pretty difficult since "holes" were not torn in the same places in the ATA and AA587 airplanes. AA587 lost its fin due to structural overoad, not just the rudder coming off at the attachment points like the ATA airplane.>In addition to that startling fact is that the Aircraft was>traveling well below VA - manuevering speed - which according>to every pilot's teachings - if you are below that speed the>aircraft is safe to withstand full control inputs with no>damage. There's a gap between sound flight training and Airbus>design principles - not Airbus' fault per se - just something>that was not considered before the loss of Flight 587.>Well, that shows a problem with "every pilot's teachings." Below VA, the airplane is protected structurally from one full flight control iinput followed by a return to neutral, not from rapid, full range oscillatory inputs. The industry and regulatory authorities as well as the NTSB are trying to get this word out as it is apparent that what you say about pilot knowledge and training is true.Don S.>>

Share this post


Link to post
Guest upsvac

I just thought I'd jump in and give Canadian pilots a thumbs up! We've gotten ourselves into some pretty compromising situations in the last 20 years or so, (Gimli Glider, A330 Glider, then this...) and yet not one fatality in any of these instances!!

Share this post


Link to post

"The aircraft made incorrect deductions based on its flightpath and performed a controlled flight into what it thought must be a runway."Not true. The plane was under fully manual control at the time of the crash. The pilots flew too low, too slow, and then when they tried to climb out by giving a sudden TOGO power command, they left it too late, and the few seconds that it tok the engines to develop full thrust - which is a characteristic of the engines not of the avionics - they were over the airfield and into the trees. The story about the autoflight trying to land because of the low speed / low altitude is pure urban legend.Richard

Share this post


Link to post
Guest Airbuzz

From what I read the pilot typed in wrong (engine-related) data into the MCDU to override some hardcoded limits for the show.Still the A320 family can be cheated.To 100% disable FBW you have to turn off two switches in the upper-panel. The result is a flight-behavior like a good old Boeing.But thats not teached in school :)

Share this post


Link to post
Guest

yes, those switches were added after the accidents...

Share this post


Link to post

I'm no aviation professional, but this rudder issue does seem to be limited mainly the A300 and A310 - see IASA's website at http://www.iasa.com.au/folders/menu/index.htm and go to the March 13, 2005 article under LATEST ADDITIONS link on left side.Does anyone know if Boeing aircraft have had major rudder issues like the Airbus? John

Share this post


Link to post
Guest Shalomar

Donny AKA ShalomarFly 2 ROCKS!!!Someone asked 'bout Boeing rudder problems. A 737 in Pittsburgh had the rudder fully deflect and jam on final, a combination (apparently) of dirty hydraulic oil and Boeing's trying to make a fail-safe system with two pumps instead of three. That and other incidents pointed up the overall lack of pilot's experience with unusual attitudes, many airline pilots today have never rolled an airplane. A crew menber could be heard urging "pull, pull" while inverted. They pulled so much they impacted tail first after rolling numerous times. NO manufacturer has been spared design mistakes, the 747 that hit a mountain in Japan had been repaired by Boeing under a "new" procedure using one line of rivets on the rear pressure bulkhead instead of two. Pressurised air explosively entered the tail as the cabin decompressed, severing the tail and hydraulic lines.Mcdonnel Douglas had trouble with the cargo doors on the DC10 and did not provide enough venting to prevent passenger floor deformation and damage to control elements should a cargo door fail. Lockheed's Tristar had doors that opened inward and so were sealed by cabin pressure, but this made it incompatible with "igloo" cargo technology. The DC10 far outsold the L10-11, years after the cargo door/venting solutions a crew and passengers regretted the fact all three "fully independent" hydraulic systems shared the same accumulator.In addition to its current troubles, Airbus is the only manufacturer to have an engine on one of its aircraft experience a transition into reverse thrust during cruise. Due to the complex nature of modern aircraft, a lot of "debugging" occurs during service life AFTER testing as well as before. Warnings of defects are not always heeded. A year and a half before a Turkish DC10 was lost due to cargo door failure, an american one landed safely after a cargo door opened at lower altitude. Two years before the fatal incident, a Concorde blew a tire on takeoff from Washington and landed trailing a 150 foot long spray of fuel from its wing which by some fluke had not been ignited by the afterburners- that time.

Share this post


Link to post

Hi Donny,Just correcting some inacurate information in your post ;)>Someone asked 'bout Boeing rudder problems. A 737 in>Pittsburgh had the rudder fully deflect and jam on final, a>combination (apparently) of dirty hydraulic oil and Boeing's>trying to make a fail-safe system with two pumps instead of>three. That and other incidents pointed up the overall lack of>pilot's experience with unusual attitudes, many airline pilots>today have never rolled an airplane. A crew menber could be>heard urging "pull, pull" while inverted. They pulled so much>they impacted tail first after rolling numerous times. Actually the 737 rudder PCU's are supplied by two independent hydrualic system with a third backup 'Standby' system. This makes a total of five hydraulic pumps available to the rudder. The problem in the design is using a single common actautor for the 'A' and 'B' systems to control the rudder. It is understood that it was a jaming of the servo valve that could have caused the accident in PA as well as one in Colorado. BTW, the aircraft in PA impacted nose first.http://www.ntsb.gov/ntsb/brief2.asp?ev_id=...A94MA076&akey=1>>NO manufacturer has been spared design mistakes, the 747 that>hit a mountain in Japan had been repaired by Boeing under a>"new" procedure using one line of rivets on the rear pressure>bulkhead instead of two. Pressurised air explosively entered>the tail as the cabin decompressed, severing the tail and>hydraulic lines.This was not a 'NEW' procedure. It was an improperly followed repair design that caused the accident. The repair design was and still is acceptable. It was the fact that the repair team used a single row of rivets where there should have been 2 rows, as per the repair, was the root cause of this accident.[url="http://www.airdisaster.com/cgi-bin/view_details.cgi?date=08121985

Share this post


Link to post

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  
  • Tom Allensworth,
    Founder of AVSIM Online


  • Flight Simulation's Premier Resource!

    AVSIM is a free service to the flight simulation community. AVSIM is staffed completely by volunteers and all funds donated to AVSIM go directly back to supporting the community. Your donation here helps to pay our bandwidth costs, emergency funding, and other general costs that crop up from time to time. Thank you for your support!

    Click here for more information and to see all donations year to date.
×
×
  • Create New...