A380 Wing Comes Off
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Congratulations to Airbus and British Aerospace for getting it so close.
The wing is supposed to break at ultimate if all of the design is right. That is what ultimate means.
If you build a wing stronger than ultimate then it is too heavy so then you might consider some weight improvement. Trouble with that is - you then may need to repeat all of the fatigue and load testing again.
In this case the fatigue testing may have initiated a small undetected crack which slightly weakened the piece of structure which broke. Simply polishing the surface of that structure at the break point may be enough to guarantee the strength to be above ultimate.
All of you potential A380 pilots should be elated.
A good question begging for an answer is
"What load exceedence spectrum was used for the fatigue testing and for how many equivalent hours of flight time?"
The wing is supposed to break at ultimate if all of the design is right. That is what ultimate means.
If you build a wing stronger than ultimate then it is too heavy so then you might consider some weight improvement. Trouble with that is - you then may need to repeat all of the fatigue and load testing again.
In this case the fatigue testing may have initiated a small undetected crack which slightly weakened the piece of structure which broke. Simply polishing the surface of that structure at the break point may be enough to guarantee the strength to be above ultimate.
All of you potential A380 pilots should be elated.
A good question begging for an answer is
"What load exceedence spectrum was used for the fatigue testing and for how many equivalent hours of flight time?"
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Grunf,
I have worked as a contractor in the US and am able to comment on skills of "assembly personnel". I was not directing the superior skills comment at design engineering personnel.
Basically a traditional UK assembly worker/fitter/mechanic will have an apprenticeship of 4 to 5 years. The first year is spent in a training school, no where near an aircraft, before being released on the shop floor with at least 12 different experienced fitters in 12 different sections over the three to four year period. Most of the US fitters are what we refer to as "semi skilled" having training measured in months rather than years. For evidence go and have a close look at 2 new 737 leading edges. You will see they are not the same with steps and gaps clearly visable to the naked eye. Then check out an airbus leading edge..all are identical with steps and gap tolerances checked with fine feeler gauges.
I have worked as a contractor in the US and am able to comment on skills of "assembly personnel". I was not directing the superior skills comment at design engineering personnel.
Basically a traditional UK assembly worker/fitter/mechanic will have an apprenticeship of 4 to 5 years. The first year is spent in a training school, no where near an aircraft, before being released on the shop floor with at least 12 different experienced fitters in 12 different sections over the three to four year period. Most of the US fitters are what we refer to as "semi skilled" having training measured in months rather than years. For evidence go and have a close look at 2 new 737 leading edges. You will see they are not the same with steps and gaps clearly visable to the naked eye. Then check out an airbus leading edge..all are identical with steps and gap tolerances checked with fine feeler gauges.
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Originally Posted by RMC
Grunf,
I have worked as a contractor in the US and am able to comment on skills of "assembly personnel". I was not directing the superior skills comment at design engineering personnel.
Basically a traditional UK assembly worker/fitter/mechanic will have an apprenticeship of 4 to 5 years. The first year is spent in a training school, no where near an aircraft, before being released on the shop floor with at least 12 different experienced fitters in 12 different sections over the three to four year period. Most of the US fitters are what we refer to as "semi skilled" having training measured in months rather than years. For evidence go and have a close look at 2 new 737 leading edges. You will see they are not the same with steps and gaps clearly visable to the naked eye. Then check out an airbus leading edge..all are identical with steps and gap tolerances checked with fine feeler gauges.
I have worked as a contractor in the US and am able to comment on skills of "assembly personnel". I was not directing the superior skills comment at design engineering personnel.
Basically a traditional UK assembly worker/fitter/mechanic will have an apprenticeship of 4 to 5 years. The first year is spent in a training school, no where near an aircraft, before being released on the shop floor with at least 12 different experienced fitters in 12 different sections over the three to four year period. Most of the US fitters are what we refer to as "semi skilled" having training measured in months rather than years. For evidence go and have a close look at 2 new 737 leading edges. You will see they are not the same with steps and gaps clearly visable to the naked eye. Then check out an airbus leading edge..all are identical with steps and gap tolerances checked with fine feeler gauges.
After many cycles any airplane will get that middle age spread. During heavy checks, aircraft are torn apart and put back together so they are re-rigged to zero time tolerances. Aircraft flown over here are maintained inspected in Europe too. With these so-called gaps or other blemishes visible after a heavy check has been completed, is it because, as you say, are the engineers here semi-skilled?
Pretty arrogant of you don't you think... athough no... since you made the comment regarding semi-silled labour.
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CAPTJNS- Sorry you dont like the facts. Read my reply I specifically said check out the leading edges of two NEW 737s....ie just delivered. I spent a year in France Delivering new Airbus aircraft to customers and know about the differences between Airbus and Boeing specifications.
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RMC:
As long as you've been exposed to both sides it is OK to comment. I did support both sides, namely in liaison stress, so I've seen same kinds of problems both ways.
In terms of QA prior to delivery I would assume both sides would work hard on that. Sadly I think money still talks stronger so some discounts, concessions etc. will bring that acceptance from the customer side, always.
As for the competence of designers - I shouldn’t comment, being a stress guy
As for skills in North America it is worth say that if you worked in few place, they are definitely different, depending on where they work.
To get back to A380 wing it is fine. Still no explanation into why this info got public. I do not think this is a valid info for general population, not even for educated amateurs. It is too complex to be discussed in FI.
As long as you've been exposed to both sides it is OK to comment. I did support both sides, namely in liaison stress, so I've seen same kinds of problems both ways.
In terms of QA prior to delivery I would assume both sides would work hard on that. Sadly I think money still talks stronger so some discounts, concessions etc. will bring that acceptance from the customer side, always.
As for the competence of designers - I shouldn’t comment, being a stress guy
As for skills in North America it is worth say that if you worked in few place, they are definitely different, depending on where they work.
To get back to A380 wing it is fine. Still no explanation into why this info got public. I do not think this is a valid info for general population, not even for educated amateurs. It is too complex to be discussed in FI.
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Grunf-Only spent 6 months in Seattle (too bloody cold) and I am specifically refering to assembly fitters on the line (not design guys or even the maintenance guys who have to meet far higher standards than the factory bods). A case in point was the 747 which had a tailstrike (JAL?). The designed repair was fine. The product support mechanic (drawn from the factory) fitted one line of rivets along each side of the repair (not two as drawn by the design engineer). You know better than I that one line of rivets on the critical rear pressure bulkhead would never be entertained as an adequate repair...even a European factory cat would not fit that but tragically that repair was completed and signed off.
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RMC:
I understand. I would like to say bad luck but this guy was really sloppy. No explanation for that except what you've said.
Cold-wise, try to work in Montreal
Anyway it is good for Airbus they got so close to 150%. Although it is always better to have a little more over 150 and then show some weight reduction that always looks nice with customers.
Cheers
I understand. I would like to say bad luck but this guy was really sloppy. No explanation for that except what you've said.
Cold-wise, try to work in Montreal
Anyway it is good for Airbus they got so close to 150%. Although it is always better to have a little more over 150 and then show some weight reduction that always looks nice with customers.
Cheers
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What Red Line? :
Wouldn't happen to a Boeing you know. No way! Just try to imagine a fin falling of a Boeing. Impossible! Although some clown once tried to tell me that a fin dropped off a 747 in Japan. What rubbish! Only happens to Airbus.
Wouldn't happen to a Boeing you know. No way! Just try to imagine a fin falling of a Boeing. Impossible! Although some clown once tried to tell me that a fin dropped off a 747 in Japan. What rubbish! Only happens to Airbus.
Just try to imagine a horizontal stabilizer falling of an Airbus. Impossible ! Just happened to a 707 (Dan Air, Lusaka).
Just try to imagine the upper portion of the fuselage falling of an Airbus. Impossible ! Just happened to a 737 (Aloha, Hawai).
Just try to imagine the bulk cargo door falling of an Airbus. Impossible ! Just happened to a DC10 (THY, Paris).
Just try to imagine the engine No. 1 falling of an Airbus. Impossible ! Just happened to a DC10 (Continental ? Chicago ?).
Just try to imagine several engines falling of an Airbus. Impossible ! Just happened to a 747 (ElAl, Amsterdam).
Just try to imagine a worn jackscrew causing a horizontal stabilizer falling of an Airbus. Impossible ! Just happened to a MD 8x (Air Alaska).
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2. Luoto - the final destructive test is only completed at the end of the life cycle tests. So the wing set in question would have completed as many cycles as any aircraft achieves in service...then failed at 147%
I thought that you had to destructively test a "virgin" as well as a full cycle piece. Didn't the Comet problem occur because a full cycle fuselage was used for the pressure tests and the subsequent "work hardened" fuselage passed the tests only for the relatively low cycle in service fuselages to fail? Or did I get the wrong end of the stick?
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AP
Airbus: Test Won't Delay A380 Delivery
Monday February 20, 7:06 am ET
Airbus Official Says A380's Failed Wing Test Will Not Delay Delivery
SINGAPORE (AP) -- Airbus's chief operating officer for customers said Monday the first delivery of the world's largest commercial jet, the A380, would not be affected by the failure of the jet's wing in a stress test last week.
"It's not a big problem at all in fact. We hope and expect it to be relatively minor," John Leahy said on the sidelines of an Airbus briefing ahead of the Asian Aerospace exhibition.
Before certifying an airliner for commercial service, aviation authorities set its "limit loads" -- the maximum strain each part is likely to be placed under during extreme turbulence or hard landings. New planes are required to resist loads of 1.5 times the limit.
The A380 wing had ruptured sooner than expected during ground testing in Toulouse on Tuesday, reaching only 1.45 times its limit load before breaking -- 3.3 percent short of target. The wing had been bent upward by 24.3 feet at the tip.
Leahy said there should not be any major modifications to the design of the plane.
"We have enough data from that test to know what needs to be done," he said. "This should have no impact on the delivery of the aircraft."
Seven airlines in the Asia-Pacific region have ordered a total of 49 A380s, accounting for 31 percent of 159 firm orders so far for the world's largest passenger aircraft -- but deliveries have been pushed back six to eight months due to production delays.
The 555-seater is due to enter into service with Singapore Airlines Ltd. by the end of the year. The aircraft has a list price of US$292 million (euro243 million).
The A380 will overtake The Boeing Co.'s 747 as the world's largest commercial jet when it enters service. Boeing announced late last year that it is launching the 747-8, a more fuel-efficient version of the double-decker plane, to compete with the A380.
Separately, Singapore Airlines said Monday it was evaluating proposals from Boeing and Airbus to supply long range aircraft, but a decision is unlikely anytime soon.
"We are evaluating (the proposals). The early submissions didn't meet our requirements in terms of delivery schedule and operational economics," Chief Executive Chew Choon Seng said on the sidelines of an aviation conference.
Singapore Airlines asked Boeing and Airbus in August to submit proposals for ultra-long range aircraft, to meet its fleet renewal needs and future expansion plans.
Airbus: Test Won't Delay A380 Delivery
Monday February 20, 7:06 am ET
Airbus Official Says A380's Failed Wing Test Will Not Delay Delivery
SINGAPORE (AP) -- Airbus's chief operating officer for customers said Monday the first delivery of the world's largest commercial jet, the A380, would not be affected by the failure of the jet's wing in a stress test last week.
"It's not a big problem at all in fact. We hope and expect it to be relatively minor," John Leahy said on the sidelines of an Airbus briefing ahead of the Asian Aerospace exhibition.
Before certifying an airliner for commercial service, aviation authorities set its "limit loads" -- the maximum strain each part is likely to be placed under during extreme turbulence or hard landings. New planes are required to resist loads of 1.5 times the limit.
The A380 wing had ruptured sooner than expected during ground testing in Toulouse on Tuesday, reaching only 1.45 times its limit load before breaking -- 3.3 percent short of target. The wing had been bent upward by 24.3 feet at the tip.
Leahy said there should not be any major modifications to the design of the plane.
"We have enough data from that test to know what needs to be done," he said. "This should have no impact on the delivery of the aircraft."
Seven airlines in the Asia-Pacific region have ordered a total of 49 A380s, accounting for 31 percent of 159 firm orders so far for the world's largest passenger aircraft -- but deliveries have been pushed back six to eight months due to production delays.
The 555-seater is due to enter into service with Singapore Airlines Ltd. by the end of the year. The aircraft has a list price of US$292 million (euro243 million).
The A380 will overtake The Boeing Co.'s 747 as the world's largest commercial jet when it enters service. Boeing announced late last year that it is launching the 747-8, a more fuel-efficient version of the double-decker plane, to compete with the A380.
Separately, Singapore Airlines said Monday it was evaluating proposals from Boeing and Airbus to supply long range aircraft, but a decision is unlikely anytime soon.
"We are evaluating (the proposals). The early submissions didn't meet our requirements in terms of delivery schedule and operational economics," Chief Executive Chew Choon Seng said on the sidelines of an aviation conference.
Singapore Airlines asked Boeing and Airbus in August to submit proposals for ultra-long range aircraft, to meet its fleet renewal needs and future expansion plans.
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So the wing set in question would have completed as many cycles as any aircraft achieves in service...then failed at 147%
Are you sure about this??
The wings completing more than 2 simulated lives is still beeing tested in Dresden. The one in Toulouse was never tested in fatigue.
And for the Comet, it was the other way round. The test fuselage (section) used for fatigue testing was used for static tests before, "coldworking" all the high stressed areas. This led to a high fatigue life of the specimen, which was misjudged at that time to the best knowledge of engineers and authorities.
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Help me sort out the ....*ahem * .... truth please
So is failure at:
1.46
1.47
or is it 1.45 times the certified number ?
3.3 percent below is not good if the FAA requires 3 pct for an easy certification.
...... geez . . . so typical - - - conficting data/reports and secrecy
So is failure at:
1.46
1.47
or is it 1.45 times the certified number ?
3.3 percent below is not good if the FAA requires 3 pct for an easy certification.
...... geez . . . so typical - - - conficting data/reports and secrecy
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Mono:
Destructive test goes after completed static tests so the guy was right.
If everything goes well they will do that, I am sure.
To add here an excerpt from Airbus VP Eng's statement fro FI:
"Garcia says the trial was an “extremely severe test during which a wing deflection of 7.4m [24.3ft] was recorded” and that the A380 wing was designed to have “no margin” at ultimate load. “We had a weight-saving programme and ‘played the game’ to achieve ultimate load,” he says."
So they did (expectedly) go to "zero margin". Whoever asked before since this was mentioned before. s I said they were saving weight.
In the end they will get out with slightly different cert reports.
"Jonathan Howes, technical director of UK-based certification consultants AeroDAC and, until recently, leading structures certification specialist for the A380 at the UK Civil Aviation Authority, says the rupture “was so close to the ultimate target that it is almost certain to allow approval to be given without the need for a re-test, but this will be subject to a negotiation between Airbus and EASA”.
Destructive test goes after completed static tests so the guy was right.
If everything goes well they will do that, I am sure.
To add here an excerpt from Airbus VP Eng's statement fro FI:
"Garcia says the trial was an “extremely severe test during which a wing deflection of 7.4m [24.3ft] was recorded” and that the A380 wing was designed to have “no margin” at ultimate load. “We had a weight-saving programme and ‘played the game’ to achieve ultimate load,” he says."
So they did (expectedly) go to "zero margin". Whoever asked before since this was mentioned before. s I said they were saving weight.
In the end they will get out with slightly different cert reports.
"Jonathan Howes, technical director of UK-based certification consultants AeroDAC and, until recently, leading structures certification specialist for the A380 at the UK Civil Aviation Authority, says the rupture “was so close to the ultimate target that it is almost certain to allow approval to be given without the need for a re-test, but this will be subject to a negotiation between Airbus and EASA”.
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RMC,
I didn´t say virgin wingset, I just said the static test article was never used for fatigue testing, so the statement "So the wing set in question would have completed as many cycles as any aircraft achieves in service...then failed at 147% " is wrong as well.
The wingset in question was not virgin, but not a slut either. Just been tested a few times before for several static load cases, flap system gap checks under deformation etc. sometimes exceeding limit load.
I didn´t say virgin wingset, I just said the static test article was never used for fatigue testing, so the statement "So the wing set in question would have completed as many cycles as any aircraft achieves in service...then failed at 147% " is wrong as well.
The wingset in question was not virgin, but not a slut either. Just been tested a few times before for several static load cases, flap system gap checks under deformation etc. sometimes exceeding limit load.
Certain comments here are somewhat misguided. Comparing leading edges gap quality or whatever on B737 and Airbus aircraft as an indication of build quality and indirectly safety, is misguided at best, and totally off the beam at worst.
Quality is not about beautiful smooth curves and so on, its about fitness for purpose. To put it another way, if the ragged edge makes no difference to performance and safety, then leave them exactly as they are - don't guild the lily, it adds to cost.
If the Boeing designers designed an aircraft in such a way that it can be constructed by semi skilled workers, then no one has a right whatsoever to draw meaningless comparisons with Airbus on the basis of the quality of its labor force.
Quality is not about beautiful smooth curves and so on, its about fitness for purpose. To put it another way, if the ragged edge makes no difference to performance and safety, then leave them exactly as they are - don't guild the lily, it adds to cost.
If the Boeing designers designed an aircraft in such a way that it can be constructed by semi skilled workers, then no one has a right whatsoever to draw meaningless comparisons with Airbus on the basis of the quality of its labor force.
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Sunfish,
You are corect about fitness for purpose.
I used leading edges as an example because a ragged leading edge does make a huge difference to aerodynamic performance. One of the reasons Airbus aircraft are so much more fuel efficient than Boings. Not exactly a meaningless issue with fuel costs as they are.
Yep Boeing over engineer their aircraft and this makes build quality less important. Checkout the Zero fuel weight of an A320 and a 737 designed to carry the same amount of people. Not meaningless either.
I do have to agree with you however there is some guilding of the lilly which is unnecessary and Airbus quality standards have historically been too high for their own good. The reality is just like cars....if you want an over egineered , badly put together thirsty beast buy American. If you want something else pay a bit more and go for something from Japan/Germany etc.
You are corect about fitness for purpose.
I used leading edges as an example because a ragged leading edge does make a huge difference to aerodynamic performance. One of the reasons Airbus aircraft are so much more fuel efficient than Boings. Not exactly a meaningless issue with fuel costs as they are.
Yep Boeing over engineer their aircraft and this makes build quality less important. Checkout the Zero fuel weight of an A320 and a 737 designed to carry the same amount of people. Not meaningless either.
I do have to agree with you however there is some guilding of the lilly which is unnecessary and Airbus quality standards have historically been too high for their own good. The reality is just like cars....if you want an over egineered , badly put together thirsty beast buy American. If you want something else pay a bit more and go for something from Japan/Germany etc.
