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Airbus Admits Problem on 320!

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heywatchthis

Well-known member
Joined
Feb 28, 2005
Posts
199
Airbus admits undercarriage problems on A320 series
09.25.2005, 07:08 AM



PARIS (AFX) - Airbus acknowledged previous jammed nose wheel incidents similar to the one which caused a spectacular emergency landing in the US earlier this week.

'These incidents all ended without a problem and we must await the end of the inquiry to know what really caused this one and if the causes are the same,' an Airbus spokeswoman said.

She was responding to a report from the US Federal Aviation Administration following the emergency landing of an Airbus A320 at Los Angeles airport with the nose wheels jammed at right angles to the fuselage.

Incidents involving nose wheels had occurred with an American West A320 in February 1999, a JetBlue A320 on Nov 1, 2002 and a United Airlines A319 -- a smaller version of the Airbus model -- on Nov 21, 2002, the FAA said Friday.

No one was injured in any of the incidents.

The New York Times reported Friday, citing FAA officials, that Wednesday's incident, again involving a JetBlue A320, marked at least the seventh time the Airbus has had problems with its nose wheels.

The French Airline Pilots' Association for its part said there had been six such incidents before 2000.

On Wednesday, the nose landing gear on JetBlue flight 292 became jammed at a 90 degree angle and failed to retract following takeoff from Burbank airport in the Los Angeles area.

With the plight of the plane carried live on national television -- and watched by the 140 passengers on seatback screens -- the crew dumped fuel and landed spectacularly but safely.
 
On one of those blog-things one of the pilots was saying that this particular gear had 'just been signed off' after a previous problem?
 
No surprises here. Airbus also hid the A300 rudder problems for 2+ years until AA 587 crashed and they are still denying any culpability.
 
yaks said:
No surprises here. Airbus also hid the A300 rudder problems for 2+ years until AA 587 crashed and they are still denying any culpability.

Whaa? AA 587's FO applied immediate full rudder in one direction and then full rudder in the other direction. Something which in certification the airplane's tail wasn't required to withstand. WWII B-17 manual warned against full rudder deflection one way and then suddenly full deflection in the other for this very reason (risk to the vertical stabilizer). If he hadn't applied rudder in that way they wouldn't have crashed.

The problem was with the vertical stabilizer structure, not the rudder. Surely you mean the composite structure holding the vertical stabilizer to the fuselage, which has been shown to develop microscopic cracks after excursions outside of normal manuevering, cracks which maintenance had found difficult to detect in inspections. Also, the rudder deflection vs. pedal deflection and pressure is speed dependent and becomes more sensitive with higher pressure forces as you speed up, it is different than Boeing rudders. I'm not shifting my blame totally away from Airbus (composite has no bend before it breaks like metal does) but as I recall the NTSB laid the blame for this one at the feet of the pilot. No pun intended.
 
I would lay the majority of the blame at the feet of the engineer in charge of developing the vertical stabilizer. I'd say that they underestimated the loads which that component would have to endure.
Also surprised the flight control computers allowed rudder deflection sufficient to cause failure in this regime.
 
A little history here, during the birth of the Dornier 328 it was discovered that full rudder input over a certain speed, (I forget the speed) would result in possible loss of aircraft. So at speeds above (I forget the speed) the rudder was not able to make a full travel ( a rudder limiter) but the amount it was able to move was more than enough for control of flight.


.
 
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To continue with the thread hijacking...

I would imagine that just about any aircraft with hydraulic-powered flight controls would have some means of reducing surface travel as airspeed increases.

However, I did read somewhere (Flying magazine maybe?) an article discussing the rudder on the A-300 and the American accident in New York. I didn't really understand what I read because it sounded so backwards to me, but that article seemed to imply that the hydraulic systems powering the rudder actually get MORE sensitive as airspeed increases. A lighter feel at the pedal and less pedal travel to achieve a given surface deflection. Sounds completely backwards, so I could have read it wrong. Anybody with more knowledge care to comment?
 
The feds should ground every A320 and get to the bottom of all of the nose gear and flap problems before innocent people are killed.
 
yaks said:
No surprises here. Airbus also hid the A300 rudder problems for 2+ years until AA 587 crashed and they are still denying any culpability.

They still blame their "HAL 9000" flight control issues on the pilots instead of the programmers as well.
 
Buckaroo said:
The feds should ground every A320 and get to the bottom of all of the nose gear and flap problems before innocent people are killed.

So now there is a FLAP problem? Which news media do you work for???
 
"The feds should ground every A320 and get to the bottom of all of the nose gear and flap problems before innocent people are killed."

Just like they grounded the 737s after the rudder problems.
 
Park the A320s!!!


Sure..

The A320 has killed a LOT of people due to pure mechanical failure!

Lets see...

Hmmm..

Oh...
The only accidents have been due to human factors....

bummer!!!
 
Some of these deaths would have been avoided in the "human error" region had Airbus utilized soft limits in there fly-by-wire system. I'm amazed Airbus hasn't changed that design. It seems to have caused more problems than it's worth. Has anyone heard of anything positive happening because of this system?
 
How many accidents have been caused by HAVING soft limits?
Being able to stall? Over G? Overspeed?


Every system has its limitations...

Believe me... I'm not trying to blow smoke in anyone's a@@.

If you understand the flight control laws... and understand the interface between the human and the automation.... its proven itself very well.

There's the high profile crashing in to the trees...
And several automation accidents (human factors)..

But there are real benefits of being able to pull FULL back stick at anytime and know the airplane will not over g and will give you eventually a max alpha climb out. (EPGWS escape maneuver)

FWIW.....

Boeing chose soft limits and a yoke...
Airbus went joystick and hard limits...

Both work with there own limits and benefits.
 
Is it me or were the majority of the recent string of crashes 737's? There are a lot of 320's flying around every day too.
 
Seems like most of the harpooning of the 320 comes from folks who have NOT actually flown it. Let's hear from a few guys with substantial AB time.
 
"Some of these deaths would have been avoided in the "human error" region had Airbus utilized soft limits in there fly-by-wire system".

I am curious, which accidents are you referring to?
 
Dizel8 said:
I am curious, which accidents are you referring to?

For your reading pleasure:

http://www.iasa.com.au/folders/Safety_Issues/others/Bilbao.html
http://aviation-safety.net/database/record.php?id=20010207-0
http://dnausers.d-n-a.net/dnetGOjg/260494.htm
http://catless.ncl.ac.uk/Risks/16.96.html#subj7
http://aviation-safety.net/database/record.php?id=20010320-0
http://aviation-safety.net/database/record.php?id=19940630-0

How many other software flaws are there? Can an engineer sitting at a desk really anticipate every single possible scenario that might occour in flight? Could even the world's best pilot do that? I think not. SOFT limits are necessary for FBW so that glitches may be over ridden.
That's why Airbus switched to soft limits in the 380.
 
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I read those reports you posted, and I fail to see how the Airbus control laws contributed to any of those accidents.

Are you implying that if the airplane had let them stall, that somehow the accident would have had a different outcome?

Maybe you could quote a few small bites from those articles that point to the probable cause being "the design of the aircraft's computer control system".
-------
 
From the very first one:

"However, according to first released findings of the Bilbao accident investigation, the ‘activity’ of this safety feature was a contributing factor in the event: the alpha-protection contradicted the desired pilots action"


"In the light of the accident occurring only four months ago, and the sometimes lengthy ‘normal’ timeframe for implementation of safety revisions after an accident, it appears to be of “amazing speed” how Airbus Industrie, - even in the absence of a final report, has already decided and performed a modification on the alpha- protection control laws. This was done in an approach “to increase the flight crew’s authority”, - as Cpt. Brandt was quoted saying by media. - A step applauded even by staunch Airbus critics among the international pilot community. A revised software version is expected to be validated this month and has already received certification by the French Civil Aviation Authority (DGAC) and the European Joint Aviation Authority (JAA). Airbus plans to implement a “rapid retrofit program” for its entire A319/320 fleet."


Either you didn't really read them or your love for the scarebus blinded you, either way I ask the same question: How many more undiscovered software problems are there? Odds are there are many more. The computer is only as good as the human engineer that does the programming and nobody can think of everything.
 
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