"A380 is a zero-crash aircraft" say Airbus

[WHBM]

http://www.menafn.com/qn_news_story_s.asp?StoryId=115501

Seems a bit of the sort of comment that comes back to haunt you.

[markflyer6580]

Did airbus not bang on about how safe all of their automation would make things?
And then watch one fly itself in to the trees:confused:

[clicker]

Umm. It hasnt got a name yet has it.

Can I suggest Titanic?

[Atreyu]

judging by the invasion of windows into the A380's flightdeck, it's a matter of time surely before some computer geek ruins the day for everyone and hacks the flight controls

Airbus doesn't even trust pilots anymore, what a strange world we are evolving into

AT ;)

[Carnage Matey!]

I think you'll find it was an Air France Captain that flew the aircraft into the trees, not the automation.

[sikeano]

doom and gloom already what are we journos

come on let us give scarebus a chance :yuk:

[Atreyu]

Titantic is very apt. Both distastefully large, and both their companies made such crass statements. Just gotta wait for the A380 disaster.

I'm not anti airbus/pro boeing by any strech of the imagination. But to make a claim an aircraft is a 'zero-crash aircraft' is a bit Radio Rental when so many factors can contribute to a crash

AT :)

[manintheback]

An excellent piece of mis-quoting and incorrect translation.

What was actually said was no single failure tech or human will cause it to crash.

Interesting to see each aircraft has a service life of 50 years.

[Greek God]

"It is as safe as it can be. We have tested the aircraft fully by conducting various failure scenarios and checking the systems extensively to avoid any single failure from happening which would cause a plane to crash,"

The operative words here are single failure - Something for which all commercial aircraft are designed. Its normally a combination of more than one which causes problems.

[N380UA]

I think you'll find that the "Zero-Crash-Aircraft" was in regards to its systems. That excludes the human factor from the flight of one of those things.

[DA50driver]

"No one item will make the aircraft crash". Great.
No go read an accident report and in 99% of all accidents there are 3 factors involved. Good luck Airbus.

[Atreyu]

And when has one failure ever brought down an airliner, every disaster I can think of is usally a chain of events and errors, both human and mechanical.

50 years is quite a long service life though, must be a fairly advanced beast under the skin.

AT ;)



{EDIT} I think about 4 people replied to manintheback's post at the same time there

[Farrell]

Fully computerised, the A380 is equipped with 100 black boxes, also known as flight data recorder (FDR) and cockpit voice recorder (CVR).

I thought those things were used to analyse CRASH data? Muahahah!!

[Atreyu]

Basically Airbus have stated no one failure will lead to a crash, just like every other airliner out there then? :E

I think they are trying to make Joe Public feel safer on such a huge aircraft by making this 'no one failure will lead to a crash' seem like a new development to the A380.

My opinion anyway

AT ;)

Farrell's observation was excellent :ok:

[Octopussy2]

"and we made sure that it carries passengers safely to and from their destinations,"

I would like to think that is a guiding principle when designing ALL Airbuses, but maybe not...???

Scary - I didn't fancy it before, but, history teaches us that statements like this are just asking for trouble!

Superstitious, moi?

[fmgc]

And then watch one fly itself in to the trees

Typical uninformed anti-airbus rubbish.

OK so it did fly itself into the trees, but only because the Captain sat there and let it happen, only taking action when it was too late.

I believe that he went to prison for it?

[Brian Abraham]

Titantic is very apt. Both distastefully large, and both their companies made such crass statements

Think the story is it was the jurnos of the day that came up with the unsinkable line because of the for then new technology - water proof doors, except if the compartment flooded completely the water went over the top into the next compartment. Also attempting to break the crossing record the speed gave no time to to take avoiding action ie no ship could survive. Stand to be corrected as its from a very fallible memory.

Blue Skies,
Brian

[Dr Dave]

Ummmm...surely the following events, on aircraft manufactured by a certain non-European company, can be put down to single component failures. Strange how rarely these are mentioned (compared with the A320 that the pilot flew into trees):
1. Aircraft crashed because of in-flight thrust reverser operation;
2. Aircraft crashed because it broke up over the South China Sea;
3. Aircraft crashed because of an uncommanded rudder movement (more than one occurrence...)
4. Aircraft crashed because the main fuel tank exploded
Etc., etc.

[Atreyu]

Dr Dave, valid points, but surely there has to be a chain of events in order for your points to occur. I would hope these things don't just happen spontaneously. Events have to line up. Example you state an uncommanded rudder movement. This would trace back to maybe incorrect parts fitted or lack of/poor maintenance or even a design flaw within the aircraft. I would say any incident or accident has several events in conjuction or in series that caused it, not one totally singular event. (unless of a bizarre or unforeseen event like a terrorist bomb, but thats nothing to do with the aircraft or its systems anyway)

Brian, very true with your statement, I was merely poking a bit of fun there with that statement :) But its true, the A380 isn't pretty!
Bulbous would be my choice of words, but i was never a fan of even the B747's look so its not an anti airbus statement! :)

Still, if i was offered the RHS seat of either in the future I wouldn't say no... lol

AT ;)

[African Tech Rep]

OK so it did fly itself into the trees, but only because the Captain sat there and let it happen, only taking action when it was too late.

Wasn’t he one of AI’s own test guys ?
Wasn’t there one that went down with CVR showing the crew constantly trying to rest CB’s / re-programme computers rather than try and fly it?
Didn’t only today an A319 guy (or two) earn his money when his cockpit went dark? – fortunately it seems he didn’t fall into the trap of “the technology will save us”.

Automation is fine – but a couple of the problems are :-
People become compliant and rely too heavily on it.
I’ll eventually do away with pilots as we know them.
(I used to be asked how difficult it was to become a pilot – recently I’ve been being asked why pilots are needed – this by members of the public)

The article is sure right about one thing – they can’t AFFORD one to crash.
Sad thing is one day one will – if it’s during early service we may be saying au reviour to Airbus – they need a few years safe service under their belts.

[DozyWannabe]

Think the story is it was the jurnos of the day that came up with the unsinkable line
True

because of the for then new technology - water proof doors, except if the compartment flooded completely the water went over the top into the next compartment.
Not entirely accurate. Brunel's "Great Britain" and "Great Eastern" had watertight compartments all the way up to the main deck. Engineering standards had already started to slip due to complacency (and, ironically, a desire on the part of the shipping companies to make their customers feel that they were in floating hotels rather than oceangoing vessels) by the late 19th/early 20th century.

Also attempting to break the crossing record the speed gave no time to to take avoiding action ie no ship could survive. Stand to be corrected as its from a very fallible memory.
The "record crossing attempt" of the Titanic is a myth - she was never built for speed, having only three turbines and screws to the Mauretania and Lusitania's four.

That being said, it's true that it was tradition for westbound mail steamers to not slow down in that region of the Atlantic - which was a very bad tradition.

Back on-topic, I do wonder how many of Airbus's more infamous comments have been attributable to mistranslation when I see threads like this.

J.

[MarkD]

Sadly Airbus types from Leahy down seem to be overexcited when placed in front of a microphone.

[Algy]

The A319 story here www.flightinternational.com will no doubt add to this debate.

[fiftyfour]

I hope its better than the A320. I've had more 'scares', 'surprises'and 'frustrations' on this aircraft in my 4 years on the aircraft than any other type I've flown over the previous 30 years.

[HEATHROW DIRECTOR]

Had an Airbus go-around at Heathrow once, for no reason I could see and having cleared it to land... Asked the crew the reason.. "We don't know; the aircraft did it, not us"!!!

[Groundloop]

"Wasn’t he one of AI’s own test guys ?"

It was one of Air France's senior A320 training captains, I believe.


"The "record crossing attempt" of the Titanic is a myth - she was never built for speed, having only three turbines and screws to the Mauretania and Lusitania's four."

On the Olympic, Titanic, etc only the centre screw was powered by a steam turbine. The two outer screws were reciprocating engines - hence views of giant pistons slamming up and down in Cameron's film. No way was the Titanic anything like the speed of the Mauretania and Lusitania.

After the early accidents with the A320 didn't Airbus learn their lesson and greatly modify their pilot training programme?

[DozyWannabe]

Mode confusion is a major ouch le derriere, but it's by no means restricted to Airbus. They made a few less-than-stellar design decisions in the early days of the aircraft, and the attitude during the Air Inter investigation was all wrong, but I don't think you can blame the aircraft for that.

Remember it was mode confusion that brought down the first TriStar, and that is still considered one of the best-engineered airliners in history.

J.

[Mr_Grubby]

I had a similar thing happen to me as the Heathrow Director did.
Few years back sitting on TMA SE DEPS (DVR) an Airbus took off from 26 at Gatwick on a DVR SID and called me in the left turn. Not right.
I asked the crew what was going on and had a similar reply to HD.
'Don't know, the aircraft is doing it's own thing'


Clint.

[FlapsOne]

FDRs and CVRs are not simply there for post crash analysis. That's what journalists think!

They are constantly referenced to provide data for monitoring and subsequent improving of systems.

Hardly an excellent observation!

[fmgc]

These stories of "the airbus is just turning left even though I want to go right" and "it went around even though we didn't want it to" are utter rubbish.

If you are flying an aeroplane with the autopilot enaged and it doesn't do what you want it to do no decent piot will sit there and do nothing, he will take the autopilot out and fly the aeroplane, be it an Airbus or Boeing, that is what pilots are paid to do.

[HEATHROW DIRECTOR]

<<These stories of "the airbus is just turning left even though I want to go right" and "it went around even though we didn't want it to" are utter rubbish.>>

fmgc.. I take great exception to your statement as far as my story is concerned. I'm not in the habit of lying. I just stated a fact - it happened. So, DON'T say I'm talking rubbish. OK??

[Carnage Matey!]

Had an Airbus go-around at Heathrow once, for no reason I could see and having cleared it to land... Asked the crew the reason.. "We don't know; the aircraft did it, not us"!!!

I don't think he meant your story was rubbish HD, just the crews explanation of it! There are no TOGA switches on the A320/330/340 series so no means to inadvertantly initiate a go-around. The aircraft can't go into TOGA mode itself as it can't command the engines to TOGA power unless the alpha floor engages. The above scenario sounds rather like somebody fouled up the approach and either went around themselves or activated the alpha floor though poor handling.


Airbus took off from 26 at Gatwick on a DVR SID and called me in the left turn. Not right........'Don't know, the aircraft is doing it's own thing'


Anyone with any sense will check the SID in the box against the chart and the map display to ensure the aircraft is going to do the right thing. Every now and then one of these incidents appears on the notice board at work. Invariably the investigation reveals the crew had the wrong SID in the FMC.

The left/right confusion is a human error, not an Airbus one. We had a spate of 767s going the wrong way round the LAM hold recently, and if memory serves me correctly those aircraft are built by Boeing.

[Mr_Grubby]

fmgc.

I stand by my story.

After 32 years as an Area Radar Air Traffic Controller I do not make up stories like that.


Clint.

[Farrell]

FlapsOne.....

I am now cowering in the corner, waiting for my punishment.

"Humour will not be tolerated in this régime!!"

[EAL747]

It sure would be nice to get one trip around the pattern in the left seat, and I don't mean the simulator. Unfortunately, some non aviator bureaucrat has decreed that I am too old.
Speaking of old, our EAL Capt Johnny Miller turns 100 December 15. he plans to fly his Bonanza around....solo. And no, Johnny doesn't particularly care what the FAA thinks.
1. Titanic is not a appropriate nickname. The Tri-tanic was named over 30 years ago. The L1011 was a fine flying machine...once you got it away from the gate. That was the problem...getting it away from the gate. It was well nicknamed.
2. Next time you watch the video of the A320 going into the woods, watch the angle of attack change throughout the entire flight, right into the woods. I think the pilot indeed tried to go around; the computer was disagreeing saying, "no-no.... gotta get best L/D first." I think those guys were along for the ride.
3. Seems to me that more than several wrecks have occurred from one glitch. I can think of the Comet, Electra, ATR72, A300, DC10, 747 as being examples. Yes I understand more than one if design defect or shoddy maintenance or bad wx is included.

[d2k73]

think you'll find it was an Air France Captain that flew the aircraft into the trees, not the automation.

From what i recall the systems on board the aircraft interpreted the pilots actions as a landing, and when the pilot tried to pull up the systems would not allow him full power and when they did it was too late, she was already in the trees!

[Bus429]

EAL 747 - could you break down your analysis of the "one glitch" accidents? (For example, to which DC-10 accident do you allude, American 191 in 1979 or Sioux City in 1989? Both crashed because of maintenance and design error).

[Carnage Matey!]

From what i recall the systems on board the aircraft interpreted the pilots actions as a landing, and when the pilot tried to pull up the systems would not allow him full power and when they did it was too late, she was already in the trees!

The systems do not second guess the pilots actions or 'interpret' manouevres as a landing. The system disengages the angle of attack protection at 100R to prevent it activating during landing. The AF captain thought he's be a smart @rse and do a 50ft fly by when even the Airbus test pilots only did it above 100R. Unfortunately he did not appreciate the widely publicised fact that the alpha protection he was relying on to complete the manouevre wouldn't activate, and when he finally cottoned on to the fact it was too late to do anything. If you watch the video the engines were still spooling up as he went into the forest. No amount of back stick was going to get him out of that situation without stalling the plane, he had neither the speed nor the thrust to recover. You couldn't recover from that in a Boeing either.
I think the pilot indeed tried to go around; the computer was disagreeing saying, "no-no.... gotta get best L/D first." I think those guys were along for the ride.

Yes he did try to go around, but look how late he did it, in a low speed, low thrust, high drag configuration with about 400 feet to fly to the tree line. The computers don't go for best L/D, they'll give you as much angle of attack as is aerodynamically possible without stalling the plane then no more. Those guys weren't along for the ride, they could have gone around any time if they chose to do so. Instead they chose to fly like morons and do a display without adequate planning and preparation resulting in a crash.

[barit1]

(For example, to which DC-10 accident do you allude, American 191 in 1979 or Sioux City in 1989? Both crashed because of maintenance and design error).
AA191 lost its pylon because of maintenance management error. The shop was using an unapproved technique to remove/replace the pylon & engine as an assembly, and overstressed the wing attachments beyond their design loads.

(Remember NTSB Chief Elwood Driver holding up a broken bolt before TV cameras less than 24 hrs. after the accident, claiming he had found the culprit? :yuk: :yuk: )

UA232 burst a fan disk also because of maintenance management error. The disk was classified "prime reliable", but that was contingent on an adequate inspection program which the shop failed to implement. The subsequent total hydraulic failure cannot be considered a design problem in the context of aircraft certification.

[sweeper]

if this topic is a boeingVairbus contest, would airbus not have to have two 380,s in teneriffe on a foggy day to catch up?
and that tragedy had nothing to do with the a/c type!
a thought......:*

[Saxon]

Agree with sweeper 100%

The only aircraft that is will NEVER be involved in an accident is the concorde in the middle of the rounderbout on the way in to LHR.

[Max Tow]

Unless it is established that Airbus did say what is alleged in the thread title, can I suggest removing the quotation marks as otherwise this reeks of the journalistic distortion of which this forum is so frequently and correctly critical.

If the actual statement was as per Greek God's quotation above, the provocative title (which, so far as I can see, is a subjective interpretation and not a quotation) would be a travesty of a more reasonable Airbus statement of design philosophy, presumably made by someone with a point of view to promote for whatever reason. Judging by some of the responses, many of the contributors to this debate seem to have swallowed the bait in classic Sun reader fashion.

[WHBM]

MT :

As the one who originated this thread with a link to a Dubai news article I can only point out it reads to start with :


'Passengers' safety on board A380 assured

Khaleej Times - 24/11/2005

DUBAI— The Airbus A380, which is considered as the world's largest long-haul airplane featuring two decks, four aisles and the capability to carry 600 to more than 800 passengers on board, is also a "zero-crash aircraft".


"Technology is what we master at Airbus. We just cannot afford to crash. The A380 has been designed to be a zero-crash aircraft and we made sure that it carries passengers safely to and from their destinations," said Jacky Joye, flight test engineer of Airbus......'

which looks to me like a quote, not a journalistic interpretation. Actually the article title "Passengers safety on board assured", which is indeed journalism, reads a lot better than the attributed quote.

Anyone know M. Joye well enough to ask ?

[Atreyu]

Who says debate is dead? lol

FlapsOne, It was an excellent observation in that it made me laugh. ;) :D

To everyone debating about the 319 that went hedge cutting, it was total pilot error, not even reheat could have got him outta that pickle. Just as they we're spooling up too... Trees really arn't good for Turbofans after all... :}

Hope eveyone takes things with a pinch of salt

AT :ok:

[Max Tow]

WHBM

Without wishing to split hairs, if the correct quote is "DESIGNED TO BE a zero-crash aircraft", what's so controversial about that as an aim?
Wouldn't Boeing have the same philosophy?

[blueloo]

Max Tow, I am glad Airbus finally decided to design an aircraft thats not meant to crash. Its taken a few years. I think all boeings since day 1 were designed to be zero crash aircraft (of course this hasnt been the case, but at least they had the right intentions)

[PAXboy]

This sounds like a technician who has been waylaid by a journo and has no idea how his well intentioned remarks will sound!!! The one that is really silly is:We have tested the aircraft fully ... I had not realised that the 380 had completed testing and is now certified ... :rolleyes:

[barit1]

I am glad Airbus finally decided to design an aircraft thats not meant to crash

In fact the A300 was in production a remarkably long time (ten years) before its first write-off in 1982. But it broke little new ground in technology, with a complete propulsion system borrowed from the DC-10-30, and none of the black magic that first appeared on the A320.

[Phil Hudson]

Wouldn't Boeing have the same philosophy?

Boeing philosophy is that the pilot is in control of the aircraft all the time, not computers, the automatics is there to help.

[Junkflyer]

They haven't met their efficiency targets, weight target, or wake turbulence claims. Airbus likes to make promises, delivering on these may be a different story.

[MetAl]

Crashproof?

Hasn't ever been anything made "idiot proof" that somewhere there isn't a better, newer improved idiot.

[Wingswinger]

As a fully paid-up member of English Pedantry I must protest at the ungrammatical nature of the expression "zero-crash". It should be "no-crash", "crash-proof" or "crashless". "Zero" is a cardinal number meaning nothing so it cannot be used in an adjectival sense.

What else can you expect when you let foreigners take over your language?!

Zero-crash ? Banzai!

edited for spelling (oops!)

[Bus429]

Barit 1,
Sioux City comments noted.
However, AA 191 was lost as the result of a combination of maintenance error, maintenance management error and design certification error.

[snaga]

Boeing philosophy is that the pilot is in control of the aircraft all the time, not computers, the automatics is there to help. That's just a well absorbed version of the propaganda ("marketing" if you prefer) story. What, in practice, is the difference between the two manufacturers when it comes to the role of automation? Very little, especially when you look to the latest aircraft offerings.

Is this entire thread not a testimony to the fact that too many pilots are not working hard enough and have too much time on their hands to pontificate about the minutaie of very little?

[MOR]

There seems to be an enormous amount of b#ll#cks being written here about the Habsheim A320 accident, from people who should know better.

Some salient points, then:

The crew though they were at 100', but were actually at around 30', due to a failure of the altimeter system - hence their inability to clear the trees.

The captain had disconnected the autothrottles, and therefore had no alpha floor protection (maybe an Airbus pilot could comment on that, I don't know the type).

The reports of an independent air accident investigator, Ray Davies, cast doubt on whether the DFDR information that was included in the report was in fact from the DFDR that was on the accident aircraft. He also found disturbing evidence of a disagreement between the Captains pitch commands and the resultant elevator angle... I remember at the time of the two C4 programmes on the subject, it was suggested that some of the protections had been disabled to allow the display at all, and that the unusual configuration resulted in an incorrect pitch command by the computers. If you want to read more, a basic account can be found at http://www.cs.york.ac.uk/hise/safety-critical-archive/2002/0466.html

I remember at the time, the somewhat pompous Bernard Zeigler (AAI boss at the time), demonstrating an A320 (at altitude) in landing and GA modes, and saying that "it cannot be the aircraft, therefore it was the pilots fault".

I also seem to recall that the pilot concerned ended up in Australia, not prison (although many would say it is the same thing ;) ) having had his French licence revoked on psychological grounds (presumably for questioning the reliability of the Airbus).

In any case, the whole affair stunk of corruption in high places, and a massive cover-up. I still have both C4 programmes on video, they make chilling viewing.

Anyway, my point is, check your facts before spouting such rubbish on PPRuNe.

[fdr]

atreyu- Which event are you referring to regarding the CBs???

Dr Dave...
TBC's rudder reversals were related to thermal shock on the dual acting servo causing jamming of the secondary servo and incorrect fluid porting according to the internal investigation done by TBC as a result of the continued investigation into UAL585, March 3. 1991, US427, September 8, 1994, and the serious incident of Eastwind 517. Both deals had correct parts/serviceable tolerances, as did Eastwind.

"National Transportation Safety Board
Washington, D.C. 20594
Safety Recommendation

Date: November 10, 1992

In reply refer to: A-92-118 through-121

Honorable Thomas C. Richards
Administrator
Federal Aviation Administration
Washington, D.C. 20591

On July 16, 1992, during a check of the flight controls in a United Airlines (UAL) Boeing 737-300, while taxiing to takeoff from Chicago-O'Hare International Airport, the captain discovered that the airplane's rudder pedal stopped at around 25-percent left pedal travel. The airplane returned to the gate and the main rudder power control unit (PCU) was removed.

The PCU was tested at UAL's maintenance facilities in San Francisco, California, on July 20, 1992. During that testing, the PCU operated in an anomalous manner. Under certain conditions, the actuator piston would move in a direction opposite to the commanded and intended input. However, during other demonstrations, the PCU operated normally.

As a result of the initial observations, the unit was taken to the facilities of Parker Hannifin, the valve manufacturer, at Irvine, California, for further testing by Boeing, Parker Hannifin, and UAL. Test results showed that the dual concentric servo valve installed on the main rudder PCU could, under some circumstances, result in motion opposite to that commanded by the rudder pedals. Boeing and Parker Hannifin then initiated a design review to better understand the nature of the reversal, to develop a design change to preclude the reversal, as well as a plan to implement the design change.

On July 30, 1992, the Safety Board became aware of the taxi incident at Chicago and the subsequent investigation of the PCU. Testing and design change efforts are continuing, and Safety Board specialists have participated in these efforts.

During subsequent testing of the rudder PCU, anomalous actions, ranging from sluggish movement of the actuator piston to full reversal in the commanded direction of piston travel, were observed when the input crank was held against the PCU body stops and the yaw damper piston was in the extend position. High internal fluid leakage was also noted. The capability of the PCU to produce force to move the rudder against aerodynamic loads was not measured. The interaction of the yaw damper and the PCU operation as observed is not fully understood. In addition, it is unknown whether the yaw damper was commanding rudder movement at the time that the UAL captain performed the rudder control check. During the tests, it was noted that lower hydraulic operating pressures aided in achieving anomalous actions. Tapping on the dual servo valve body or actuator summing levers prompted the PCU to return to normal operation. Releasing the force on the input crank also returned the PCU to normal operation.

In normal operation, the pilot applies force to the input crank through the rudder pedals. If the pilot releases pressure on the pedal when a direction reversal occurs, the tests show that the PCU should return to normal operation. However, it is highly unlikely that pilots would respond to a rudder reversal by releasing pedal pressure. If, as is for more likely, rudder pressure is held until the rudder has reversed position, the centering unit may supply sufficient force to the input crank to sustain the anomalous condition even though pedal pressure is released.

Analysis by Boeing and Parker Hannifin shows that the potential for rudder reversal could exist in all B-737 main rudder PCUs. The internal stops of the dual concentric servo valve can allow the secondary slide of some valves to overtravel under some conditions. Normally, the primary slide moves about 0.045 inch before the secondary slide moves. If the primary slide is pinned or jammed to the secondary slide, control inputs resulting in the normal movement of the primary slide can lead to the overtravel of the secondary slide. If the overtravel of the secondary slide is sufficient, hydraulic fluid could be routed through a flow passage located outside the normal valve travel range that could result in piston (and rudder) motion in the direction opposite to the input command.

According to Boeing and Parker Hannifin, the effects of an overtravel condition of the secondary slide would not be apparent during approved acceptance tests. Accordingly, one part of the acceptance test was modified to facilitate the investigation. During this rest, the primary and secondary slides were pinned together to prevent relative motion and were moved through an extended range of motion, as allowed by the internal secondary stops. This range of motion is greater than the normal range of motion of the secondary slide. As the overtravel progressed, the valve porting moved out of normal range, and the pressure and return porting to the respective slides of the actuator piston were interconnected and eventually reversed. The initial effect was excessive internal leakage. Full movement of the slide produced a 3,000 pounds per square inch (psi) reversed pressure drop across the actuator piston with the leakage slowed.

Boeing and UAL have developed a field test procedure to verify the proper operation of the dual servo valve. A total of 212 UAL B-737 airplanes were checked. One main rudder PCU was removed as a result of "hissing" sounds during part of the test. The source of these sounds was attributed to minor leakage in the PCU that was not associated with the dual servo valve. The unit passed acceptance tests and could have been returned to service. There were no other indications of abnormally operating PCUs during the fleet-wide checks. Tests and design analysis indicate that the anomalous operation will occur only when a unique condition prevents independent movement of the primary and secondary slides of the servo valve (a condition that could develop suddenly or occur intermittently). Thus, a onetime check may not ensure that reversal will not occur.

The dual servo valves removed from the B-737s that crashed in Colorado Springs, Colorado on March 3. 1991, and in the Darien Province of Panama on June 6, 1992, were also tested. The results show that a 50 percent pressure drop could have developed on the Colorado Springs unit if a failure mechanism produced an overtravel of the secondary valve slide. As understood thus far, if such a pressure drop occurred, the main rudder PCU could only develop 50 percent of the rudder hinge moment capability, working in the proper direction. The pressure drop would be similar to losing either A- or B redundant hydraulic systems. Moreover, the results show that a complete pressure drop, without reversal, could have developed on the Panama unit only if a failure mechanism produced an overtravel of the secondary slide valve. The unit would lose hinge moment capability, but movement of the rudder in the opposite direction beyond neutral would not occur.

Boeing aerodynamic data for the B-737-200 airplane shows that full rudder deflection (approximately 26 degrees) may be uncontrollable with full control wheel deflection (approximately 107 degrees) under certain conditions. Flap position and airspeed are important when determining controllability during full rudder deflection.

Historical maintenance data shows that there have been five other incidents related to the main rudder PCU. It is believed that two of them were detected in flight.

On July 24, 1974, the flightcrew of a: B-737 reported that the rudder moved "full right" on touchdown. The investigation revealed that the primary and secondary control valves were stuck together by a shot peen ball lodged in the valve.

On October 30, 1975, the flightcrew of a B-737 reported that the rudder pedals moved to the right "half-way" and then jammed. This action was repeated three times and then corrected by cycling the rudder with the standby rudder system. Further examination indicated that the system was contaminated by metal particles.

Another report on October 20, 1975, indicated that during a PCU inspection a jammed control valve was found. 'The data associated with this report is insufficient to determine the cause of the PCU removal.

On August 31, 1992, a B-737 reported that the rudder "locked up" on approach and that the flightcrew initiated a go-around and activated the standby rudder system. The landing was uneventful. The examination of the PCU revealed internal contamination and worn seals. It was suspected that high leakage from the worn seals resulted in the PCU having a limited capability to generate enough force to move the rudder.

On November 8. 1990, during an overhaul, a PCU was found to have internal corrosion. The primary slide was stuck at neutral to the secondary as a result of corrosion. There were no reports of malfunction prior to the disassembly.

Boeing and Parker Hannifin are currently developing design changes to the dual servo valve that would limit the travel of the secondary slide to eliminate the potential for pressure and return porting reversal. The Safety Board understands that the rudder PCUs would most likely be returned to Parker Hannifin for modification. Newly defined tolerances would require that parts from the dual servo valve be selectively fit and/or modified to produce acceptable test results. Boeing is planning a retrofit program.
...

NTSB recommends

Require that Boeing develop a repetitive maintenance test procedure to be used by B-737 operators to verify the proper operation of the main rudder power control unit servo valve until a design change is implemented that would preclude the possibility of anomalies attributed to the overtravel of the secondary slide. (Class 11, Priority Action) (A92-118)

Require that Boeing develop an approved preflight check of the rudder system to be used by operators to verify, to the extent possible, the proper operation of the main rudder power control unit servo valve until a design change is implemented that would preclude the possibility of rudder reversals attributed to the overtravel of the secondary slide. (Class II, Priority Action) (A-92-119)

Require operators, by airworthiness directive, to incorporate design changes for the B-737 main rudder power control unit servo valve when these changes are made available by Boeing. These changes should preclude the possibility of rudder reversals attributed to the overtravel of the secondary slide. (Class 11, Priority Action) (A-92-120)

Conduct a design review of servo valves manufactured by Parker Hannifin having a design similar to the B-737 rudder power control unit servo valve that control essential flight control hydraulic power control units on transport- category airplanes certified by the Federal Aviation Administration to determine that the design is not susceptible to inducing flight control malfunctions or reversals due to overtravel of the servo slides. (Class II, Priority Action) (A.92-121)

Chairman VOGT, Vice Chairman COUGHLIN, and Members LAUBER, HART, and HAMMERSCHMIDT concurred in these recommendations."


By: Carl W. Vogt
Chairman


no wrong parts.....
:confused:

http://www.ntsb.gov/events/usair427/images.htm
http://ntsb.gov/Events/usair427/items.htm
http://www.ntsb.gov/events/usair427/docket/d206.pdf
http://www.ntsb.gov/Recs/letters/1999/A99_20_29.pdf
Simulation as an Atmospheric Motion Analysis Tool for Accident Investigation
http://www.ntsb.gov/publictn/2001/AAR0101.pdf


D. Crider, National Transportation Safety Board, Washington, DC
AIAA-2004-5034
AIAA Modeling and Simulation Technologies Conference and Exhibit, Providence, Rhode Island, Aug. 16-19, 2004
[numerical modelling of vortex entry by B737-200, using matlab simlink, sobering stuff]

at least the b737-800/900 servo depowering is better.

cheers

[ATC Watcher]

Interesting how 100 computers became 100 " Black boxes " then 100 FDR-CVR. and how a test flight engineer became the spokesman for Airbus .

Goog journalistic work I would say.

As to the bashing of Airbus , of course the 787 will have no automation whatsoever, and the 777 is cable driven :ok:

[Carnage Matey!]

The crew though they were at 100', but were actually at around 30', due to a failure of the altimeter system - hence their inability to clear the trees

If you can't visually judge the difference between 100' and 30' your landings must be shocking!

The captain had disconnected the autothrottles, and therefore had no alpha floor protection

Thats not entirely correct. The alpha floor is available with the autothrust disconnected, but it is not available below 100R as it disables itself for landing, which is why it did not activate at Habsheim.

I still have both C4 programmes on video, they make chilling viewing.

Having watched the ludicrous excuse for journalism that was the Dispatches program I'd be loathe to trust anything Channel 4 told me. They don't have the best reputation in matters aviation.

[Captain104]

@Carnage Matey

It seems to me you are one of the few competent posters in this thread. What a collection of mis/half/uninformed comments here.

Regards

[lomapaseo]

Anyone know M. Joye well enough to ask ?

I know him fairly well. Top flight engineer and a decision maker regarding safety of flight.

I've followed this thread from the start and have seen some keen observations about just what contributes to a zero crash airplane. Most everything else in this thread is a debate about semantics.

Safety proffessionals don't care much about debating semantics and we certainly don't write news articles for the public. We do care about meaning however, and I'm happy to see that many on this forum have got that about right.

Now it's up to Airbus PR to clarify the meaning at least in the sense of fair marketing value.

[fmgc]

Anyway, my point is, check your facts before spouting such rubbish on PPRuNe.

MOR, I would suggest that you do the same, you are totally inaccurate in your comments.

You might find this interesting. (http://www.cs.york.ac.uk/hise/safety-critical-archive/2002/0466.html)

[BOAC]

Just to endorse the post by Carnage - I'm sure anyone who knows anything about an event or issue will probably not recognise the same when they see/hear the media description of it, and yes Channel 4 is well known for getting things wrong and were actually found guilty of this in a trial.

It is possible that the quote 'statement' from AB was either NOT what the man said, but a 'journalist's licence' 'titilation' of the statement OR it was a poor translation from the French. It is also possible he did say it, of course, but I would be - no - must be kind!

I think very few of us involved in aviation believe in the possibilty of a machine with NO pending failures or design faults which could cause a disaster (even more so when software has a huge hand in things). History is, (as someone said vis-a-vis the Titanic) littered with 'unsinkable'/'unbreakable' proven wrong, so I suspect it is a misquote - at best. It would also, I suspect, leave AB wide open to massive legal claims for damages if they were 'wrong'?

[barit1]

Bus429
OK, I'll accept the "design certification error" on the DC-10 re consequences of pylon departure; BUT the B747 fleet has lost (I believe) two freighters when an inboard pylon departed and carried the outboard away as well. It's pure luck this hasn't happened on a pax 747.

Don't know if the Airbus types are similarly vulnerable.

[DozyWannabe]

I suppose one thing that events like these over the years show is that while competition between privately-held entities can be good in terms of bringing products to market, and providing customers with what they want, there are occasions when safety is compromised as a result.

Examples include the case of the Stella, when the unofficial practice of two companies 'racing' to the Isle Of Wight resulted in severe loss of life, the aforementioned Titanic, when an extended arrangement of watertight doors may have caused added inconvinience for passengers, but may well have saved the ship (the Lusitania and Britannic being unfair comparisons due to the probable involvement of ammunition), then later the DC-10, where a desire to reach the market ahead of Lockheed led to corners being cut in the design stage - cases in point being AA191, where a redesign of the hydraulic slat actuator system would have prevented the stall which claimed the aircraft despite the loss of the engine and pylon, and of course the infamous cargo door locking issues which later caused similar problems in the 747 Classic as well.

I must say that in context, the Airbus comments do read more like he's talking about a 'crash' as it applies to the onboard computers. Unfortunately it is in the nature of commercial entities to attempt to cover their arses in cases like these, and no-one is really blameless here. The controversy surrounding the Habsheim accident is well documented above, but lest we forget, Boeing did their best to argue that pilot error was the cause of the Colorado Springs accident - and here is where an overly litigious culture on both sides of the Atlantic should definitely take some blame.

[MOR]

If you can't visually judge the difference between 100' and 30' your landings must be shocking!

You completely miss the point. When you are landing, you are judging height visually (or with the help of an electronic voice). In this case, the pilot was basing his flight path on the barometric altimeter, which was reading incorrectly.

fmgc

What's your point? The article you link to is the same one I was quoting from...

BOAC

I might agree with you were it not for the relatively large amount of empirical evidence that the programme was based on. Perhaps you would care to comment on exactly what in those two programmes you found inaccurate.

I guess you three must be Airbus drivers, as you seem very keen to accept the AAI line on this accident... :}

[Carnage Matey!]

In this case, the pilot was basing his flight path on the barometric altimeter, which was reading incorrectly.

Just below and left of the barometric altimeter display is a radio altimeter display. The FO also has an indepent radio altimeter display on his PFD. Not reslving the 70' difference between the two readouts sounds a bit gash too me.


guess you three must be Airbus drivers, as you seem very keen to accept the AAI line on this accident...

I've flown Boeing and Airbus and I can tell when someone is attributing blame to a system which isn't responsible for it. The Habsheim pilots messed it up. End of story.

[DozyWannabe]

MOR
You completely miss the point. When you are landing, you are judging height visually (or with the help of an electronic voice). In this case, the pilot was basing his flight path on the barometric altimeter, which was reading incorrectly.

...The article you link to is the same one I was quoting from...

You're selectively quoting though.

What that article suggests is that mistakes were made on both sides - Airbus, for being over-confident in their computer technology (which was later remedied - though unfortunately not without further loss of life), and the pilots for not taking sensible precautions, like making sure the barometric altimeter was correctly calibrated before take-off.

What saddens me is that this culture of 'mine's better than yours' is actually hurting the cause of safety, because both manufacturers are too busy tearing chunks out of one another rather than concentrating, or dare I say it collaborating, on their designs to make air travel safer for everyone.

[BOAC]

Perhaps you would care to comment on exactly what in those two programmes you found inaccurate - MOR - read my post again?

[Atreyu]

Wow, i've never seen such mud slinging, between airbus and boeing 'camps' and individual's themselves! lighten up!

fdr, CB's? :confused:

AT ;)

[Flight Safety]

What troubles me about the quote from Mr. Joye (if indeed he said this), is that a flight test engineer could become very complacent during flight test, if he believes he's testing an already flawless design. I want test pilots and flight test engineers to have the absolute freedom to challenge a design if they find or think there's something wrong with it.

A test pilot or test engineer must be constantly looking at everything and having full dialog with the design engineers during flight test. Both groups (flight test and design engineering) must be working together to make sure a new aircraft is as safe as it can possibly be, making whatever changes they feel are necessary to achieve that goal. A test pilot or test engineer who's not doing this because he believes (or has been told) that he's testing an already perfected design, is nothing more than management's glorified rubber stamp.

Flight Safety

[Grunf]

DozyWannabe:

Too bad this doesn't materialize (cooperation). However some level exists on critical matters for example on problems with vapors in wing reservoirs or problems with the wiring.

This types of problems do get the experts in the field around the same table (all the major manufacturers + regulators) in order to extract some mutually beneficial solution (SFAR 88 etc).



Flight Safety:

From my experience Test Pilots and Flight Test Engineers do get involved from the beginning, starting at conceptual phase. As soon as you start putting down the "orange" parts you get them in the game, even earlier if test pilot is in mind.

I remember a specific egress door being designed to accommodate a slightly "balky" figure of a certain chief flight test pilot (including his parachute). Good thing it was never tested.

Of course you involve them in each and every phase of the project. Again, from experience, they were quite instrumental in the flight test phase.Also, knowing them helps a lot, in terms of trust, and consequently it helps in getting back to the board (not literally) and resolving "issues" arising from flight tests.

So, my guess the guy who said that is more then competent. However, what comes out and gets misinterpreted is another story.


I guess in everyone's interest is to produce the safest possible product in order to reduce the possibility of failure. I guess AI's PR team thought it would be a right thing to say. Little they know...

Cheers

[DingerX]

lomapaseo's right, more or less, "Zero-crash" and what it means are a matter of semantics. And, whatever it means, there are plenty of single failures that will lead to a crash: for example, anything that causes massive structural failure is "game over".


But I wouldn't fault Joye too much. On the marketing side, he's right: on a high-profile aircraft like this, you cannot have the thing crash, at least not before hundreds are built. The Swissair MD-11 didn't just kill Swissair, it killed the aircraft as well. The Concorde was killed by its first crash. The Comet -- well, I think the RAF is just now or has just recently retired those airframes, but its commercial service was slaughtered by a design defect.

They can't afford to pull an A320-into-the-trees stunt; or any of the more memorable Paris airshow stuff. So saying it's a "Zero-Crash Aircraft" really can't hurt them. If it does, it's over anyway.

[PAXboy]

Flight Safety ... a flight test engineer could become very complacent during flight test, if he believes he's testing an already flawless design. I want test pilots and flight test engineers to have the absolute freedom to challenge a design if they find or think there's something wrong with it. Makes sense to me, a Pax. The comparison I am going to draw will probably be rejected as nothing like the testing of IT systems on an a/c.

When testing computer systems that take human input and process it and produces results, they are (usually) tested in the following manner. The tester is shown how to use the system as if it was already finished. The tester then designs test that follow the correct pattern of usage and those that will not. In other words, they also test a system by acting as someone who had not been correctly taught how to use it and see what faults are generated (if any).

Now, flight crew are trained how to use the equipment but may make a mistake. Does this suggest that the system must be tested - at least in part - by those who are not part of the design team? Perhaps they already do.

In all walks of life we have seen people design systems ranging from a paper based form [fill in the blanks] to a computer system to run the trading floor of international banks and if you send in someone who has never seen the system before, show them what they ought to do and then wait ten minutes as they find the failure point for you!

[G-DANM]

I think airbus must remember that the A380 is not going to remain a spotless aircraft just rolled off the production line with brand new parts. Even with all their computers there is always a human element in the engineering side that is impossible to remove. If they made the plane pilot proof, all it needs is for an engineer to bodge a job on it (Alaskan MD83 rings to mind) and it can be enough to bring the plane down. Nothing to do with Airbus but as with all air crashes, in the eyes of the customer the aircraft is at fault.

[MOR]

DozyWannabe

pilots for not taking sensible precautions, like making sure the barometric altimeter was correctly calibrated before take-off.

If you read the article, you will discover that the crew did perform an altimeter crosscheck before departure, and that the error occured between then and wheels-up. It wasn't a calibration error.

Carnage Matey!

Just below and left of the barometric altimeter display is a radio altimeter display. The FO also has an indepent radio altimeter display on his PFD. Not reslving the 70' difference between the two readouts sounds a bit gash too me.

How could that be gash? The article states that the altimeter error occurred after the runway crosscheck. Once the aircraft is off the ground, there is no valid crosscheck between the two (barometric and radio that is).

Again, from the article, the captain had deliberately chosen to NOT use the radalt, his reason being that the altimeter and VSI readouts, being analogue, were easier to interpret correctly.

He was also right to do so so another reason, which is that radalts are prone to jumping around as you fly over ground obstacles. You should NEVER use a radalt as a height reference when flying at low level, unless you are flying in the protected area where it's uses is intended (ie on the final part of an ILS approach).

I'm not trying to excuse the crew, simply to point out that some of the comments regarding this accident are well wide of the mark.

Particularly laughable is the idea that, because C4 may have made a mistake in some of their stories, everything they do is automatically suspect. In these programmes, they used very reliable experts and the actual DFDR information from the accident aircraft (allegedly the accident aircraft, anyway). What Ray Davies found was that when the captain commanded a climb, the software over-rode him and commanded a pitch reduction. No matter what the captain did, he was never going to recover from that position. Of course if it had been a Boeing he might have got away with it, but that is neither here nor there. I don't rate either manufacturer over the other, they both make nice aircraft with, occasionally, fatal flaws.

Not like my favourite 146, not one of those has ever crashed through mechanical or avionic failure... but that is an argument for another day. ;)

[Carnage Matey!]

How could that be gash? The article states that the altimeter error occurred after the runway crosscheck. Once the aircraft is off the ground, there is no valid crosscheck between the two (barometric and radio that is).

Its simple airmanship. You've got one, possibly two baro altimeters saying 100 ft. The visual picture looks like less than 100ft. You have two independent radio altimeters indicating 30 ft. You have an aural auto callout as you descend below 100ft. You've got a third standby baro altimeter reading something else. Something in that picture doesn't add up and to press on with an unresolved conflict like that is rather poor decision making. Even if you don't want to use the rad alt because of ground obstructions (and IIRC the display line was along the runway, hence no large objects on the ground to affect the reading), there's still a 70 ft discrepancy between the radio and baro altimeters, which is 40ft too much even with maximum tolerance on the 320 baro.

Particularly laughable is the idea that, because C4 may have made a mistake in some of their stories, everything they do is automatically suspect

May have made A mistake!!!??? Many of their 'showpiece documentaries' have been shown to be little more than works of fiction from their creators with barely more than a glancing blow at the truth. It would be intersting to run a poll amongst the professional flying community to see who really gave any credence to a C4 program related to aviation.

What Ray Davies found was that when the captain commanded a climb, the software over-rode him and commanded a pitch reduction.

At precisely what stage did that occur, because you'd best have precise facts if you want to make allegations in a TV show. Did this override occur before or after the go-around was sequenced? Was any form of alpha protection triggered by this time? Was the pitch reduction in response to the decaying speed caused by bringing the thrust levers back to idle late in the flypast? None of these points seem to be addressed in your posts. Its easy to selectively quote events in a TV show. It doesn't mean thats the full story. A few seconds here or there makes all the difference but Joe Public will never know or understand.

No matter what the captain did, he was never going to recover from that position

Couldn't agree more. He'd flown himself up a metaphorical valley with no way out. Nor would he have been likely to have recovered in a Boeing. He'd probably have been flying in stick shaker for most of the flypast and an attempt to increase pitch at the end would more than likely have seen him stall out of the sky and go into the forest nose first rather than tail first.

[BOAC]

Severe thread creep here(!) but I must side with CM here, and having spent some of my flying career at 100' or below I say that IMO NO sensible pilot would attempt to fly at 100' AGL using a pressure altimeter. Also any non-sensible pilot who did that should have been a little concerned to see 30' of air beneath the a/c. The way I see this accident (NB personal opinion only) is that the attempt to complete a low, slow fly-by was ruined by doing it downwind (windsock clearly visible), causing the Captain to attempt to fly even slower to reduce g/s, leaving him too low,slow and with engines spooled down. Cause then, IMO 'Display-itis' - a well known cause. Forget IMO 'altimeter errors'

Regarding the Boeing/AB thing, it IS debatable whether Mr B would have give him the last few feet with the last remaing 'spare' knot or two - sufficient maybe to just brush the trees - but as CM says, it was probably the AB protections which stopped the aircraft stalling and dropping in wing down which would probably have killed most on board.

Maybe the mods can split this thread so we can continue discussions about display flying and second-rate TV stuff and return this thread to whether the 380 is completely SNAFU proof?

Edited to add (again) my favourite cartoon, seen on the AIS desk at Tegel just after the crash: two birds in a nest, one says "Qui a dit merde?" :D

[fmgc]

MOR

Don't forget that the article that you are quoting from are the pilot's comments in response to the official investigations so perhaps a little squewed from the truth.

Not matter how low the chap flew he should not have been relying on the protections to give him full power anyway. He should have just gone around and put the thrust levers into TOGA.

He did go to prison by the way:

We already know that the French authorities aren't shy about accusing airmen of criminal acts. Captain Michel Asseline was imprisoned after crashing an Airbus at an airshow at Mulhouse-Habsheim in Alsace, France in June 1988. While Asseline may have messed up in a big way (this is still a subject of vigorous debate), was this truly a criminal act?

Taken from:

Aviation Today Article (http://www.aviationtoday.com/cgi/am/show_mag.cgi?pub=am&mon=1000&file=10editor.htm)

[Joetom]

Much good information.

Must remember in the early years of 320 ops. 4 big accidents.

1. Air France/Trees
2. Indian Airlines/Landing Short
3. Air Inter/as above
4. Lufthansa/Landing Over Run

Many other 320's had the close shave.

Aircraft/Pilot interface training then increased, shame it took so long.

I belive the 380 will not have the same problems as the old 320, I do think she will have problems with lack of investment at the airports.

I belive the later 380's, say 2011/12 will be a Boeing Beater.

[Carnage Matey!]

1. Air France - discussed above.
2. Indian Airlines - inappropriate use of Open Descent mode causing high rate of descent close to the ground and recovery action taken to late. Could occur using FLCH on a Boeing as well.
3. Air Inter. Mis-selection of 3000fpm descent rate of instead of 3 degree flight path angle. If you can't tell the difference.......
4.Lufthansa - the only one of the four that did not contain an element of gross mishandling.

Many other 320s had the close shave? How many 737s have been lost due to rudder hardover?

Whenever somebody fouls up in an Airbus they immediately blame 'the technology'. Why didn't we seem the same damning of the 757 after 'the technology' flew a 757 into a mountain in Cali? If you tell the autopilot to do daft things it'll do them unerringly. It's not a substitute for airmanship and common sense.

[DozyWannabe]

4. Lufthansa/Landing Over Run

At the risk of further divergence, didn't a similar issue almost claim a 146 at EGLC (had it been a wet runway it would have almost certainly run off the end)?

[Joetom]

Am only pointing out 380 will not suffer same as early 320's.

Had 320 Aircraft/Pilot interface training been up to scratch at the start of 320 ops, Airbus sales would be through the roof now.!!!

[PAXboy]

Am only pointing out 380 will not suffer same as early 320's. True, the law of experience says that it will suffer differently to the early 320s. Perhpas, in ten years time, folks will be saying, "These new ones are so much better than the early 380s."

That is not to invite such things but any new machine as complicated as the 380 (nothing to do with size) will have teething troubles. Nothing works straight out of the box - not even 100% of matches! So, we must just guard against the failures and be watching out for things going wrong. For, go wrong they will.

[Hangin' on]

So, using the last 50 years advances in technology as an example....in 50 years time the 'advanced technology' of the A380 will be the equivalent of.....a Comet? a DC3? (and that doesn't take into account the obvious acceleration in tech over the next 50 years):8

[PAXboy]

Hang. You naughtly leg-pulling little devil you!!! But I shall take the bait. :} My suggestion is not to do with the generation of technology but the newness of it.

When typewriters were invented they would have gone wrong quite a bit until people worked out how to make them and better and operate them better. Trains, planes and automobiles all followed the same process. The difficulty for new a/c is that they will have systems (or variations of) that are new and they cannot be right 100% first time. The Comet taught us some lessons and any series of related prangs will teach a lesson.

When developing a new motorcar, it is cheap and simple to test them to destruction and to drive them into walls to see how they behave. With a/c we have to (generally speaking) model on computer and then wait to see if any real prangs occur. Who knows what lessons the A380 will teach? Perhaps none. Perhaps only less critical systems will fail but empirical testing is the only one that we learn by.

Naturally, no one wants a prang but only a few admit that they will happen. The commercial world understands as well politicians that, customers/voters do not want to know the truth.
--------------------
"I tell you, we are here on Earth to fart around, and don't let anybody tell you any different." Kurt Vonnegut, Jr.

[Grunf]

Thinking of the advanced tech and A380 I assume you will see more of this debate with 787 and A350 then on A380.

What is really "new technology" on 380 is very questionable. Size is not the matter, apart from the operational side (passenger loading/unloading) - meaning that this size of a/c are flying for some time (see the issue of vortex generation).
Anyway new technologies will appear with 787 and 350 so let us see how good will be the application of stuff used on CFR 23 built models (GA, some of the business aviation models) in large commercial type a/c.

What I specifically mean is the new engine and the all-composite fuselage of that size.

To claim for that absolute safety (and reliability) will be a challenge.

For 380 it is quite a safe estimate.

Cheers,

[DingerX]

Many other 320s had the close shave? How many 737s have been lost due to rudder hardover?

Whenever somebody fouls up in an Airbus they immediately blame 'the technology'. Why didn't we seem the same damning of the 757 after 'the technology' flew a 757 into a mountain in Cali? If you tell the autopilot to do daft things it'll do them unerringly. It's not a substitute for airmanship and common sense.

In the same period from first flight, the 737 suffered three hull losses: one was CFIT on an attempted landing with visibility below minima; the other two (1. singe engine failure past V2, Captain throttled up, but noticed no engine response, aborted T/O at 50ft AGL resulting in an overrun; 2. on a non-precision approach, letting the airspeed and altitutde drop -- ordered to go around, they throttled up and raised flaps), are likewise incidents of operator error, but in which one might speculate that the pilots' experience on DC-6/7s did not help them with the response and acceleration characteristics of first-generation jets.

In the same time, there are 4 A320 hull losses. Once again, to any reasonable person, operator error is the cause -- dumb things that people do from time to time. But an unfamiliar interface philosophy can and does help people do dumb things, particularly if the years of training the operators have received in the past now becomes negative training.

What's amazing about the A320 is that, even with an airshow crash a few months after its certification, it managed to sell pretty well.

It took the 757 13 years to crash. That might be why people don't think immediately of automation-related crashes with it; or maybe it's just that it doesn't feature a full glass cockpit and fly-by-wire control system.

Technological advance has its pitfalls, above all when "experienced" humans are thrown in the mix. For the A380, I'm sure Airbus has many competent people working on trying to find the problems before fate does. But the stakes are high, especially since the pride of European Industry is riding on this. The closest parallels to such political stake being put in an airliner are the Concorde and the Tu-144.

[Algy]

Joetom,

Airbus narrowbody sales 3,700 and counting; Airbus total sales 5,700 and counting. What would count as "going through the roof" in your view?

[747FOCAL]

Are you sure they didn't mean no cash return for Airbus? :E

[African Tech Rep]

The closest parallels to such political stake being put in an airliner are the Concorde and the Tu-144.
And basically the French caused the demise of these :sad:

[er340790]

Just hope they don't have to rearrange the following before long ....
A BEFORE COMETH PRIDE FALL

[Boy]

This thread, which started as a result of a poor translation and / or a misunderstanding, continues unabated. (Long live free speech!). It has thus become less a matter relating to Airbus than to the continuing need for PPRuNe to service the needs of those who just need to express their notions, prejudices and hang ups.

I say this as the latest posters don't seem to have read the early part of the thread. They just seem to dip in to express their 2.5 pence worth regardless. An undoubted consequence of free speech ...

[barit1]

"This is your computerized crew speaking. Welcome aboard your Air Erroneous flight 678 this morning - the most advanced aircraft in the skies. Your captain and first officer have been superseded by computers.

"So fasten your seat belts, sit back and relax, and know that nothing can possibly go wrong (click) ... possibly go wrong (click) ... possibly go wrong (click) ..."

[Ignition Override]

As for design flaws or trouble spots etc, how about the DHL A-300 which was hit outside of the left engine on departure from Baghdad a couple of years ago? It still amazes me that those pilots were able to fly it back arouhd by using the throttles for all primary control, never mind airspeed. :ugh: What did they consume later to reduce the huge adrenaline surge? Does any other airline now fly into Iraq?

Maybe this was not a design flaw, because the aero. engineers never anticipated a heat-seeking missile impact, but if all hydraulic lines ran together (fusing?) in one small area, is this sort of hydraulic "junction" common in McD. Douglas, Boeing, Fokker, Dornier, Embraer and CRJ aircraft? Maybe it is far enough from the engines to minimize the chance of damage from turbine blade shrapnel :( ?

[DozyWannabe]

JAL123 (747SR) had it's 'hydraulic nexus' in the tail, which protected well from engine disintegration, but unfortunately left it very vulnerable to aft pressure bulkhead failure.

IIRC newer aircraft (certainly SLF-carrying ones) have valves in the hydraulic system to prevent leakage in case of a damaged hose.