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asuflyer
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Updated: QR finds surface coating cracks in early build A350

Sun Jan 03, 2021 9:55 pm

A QR A350, A7-ALL MSN 036, a 4 year A350, was being prepped for paint removal from the standard QR livery and repaint into the Qatari World Cup 2022 livery at SNN when IAC engineering discovered that the airframe had premature cracks in the composite fuselage. The aircraft will be ferried to TLS for repairs by Airbus. Although it is unknown the extent of the cracks, this event is somewhat significant as it is the first A350 to be entirely stripped for repainting and arises the question if other A350 aircraft will have similar issues when they are stripped for repaint. The aircraft apparently was also involved in a ground collision at MLE in 2018 and repaired however stabilizer damage was also found as a result of the inspection.

The aircraft post paint removal prior ferry from SNN to TLS

Image

https://aviation-safety.net/wikibase/212990

https://twitter.com/TierneyOisin/status ... 7130655745
 
TC957
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Re: QR finds composite cracks in early build A350

Sun Jan 03, 2021 10:11 pm

Not good, I forsee another public hissy fit coming from AAB....
 
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LAX772LR
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Re: QR finds composite cracks in early build A350

Sun Jan 03, 2021 10:19 pm

Well, not news anyone would want, but hardly some kind of anomaly.... as cracking throughout fuselage, empennage, wings, internal engine parts, etc etc etc is nothing new for newly launched (or even some seasoned) models.

The important thing is that a maintenance regimen did its duty, and preemptively found these (whether scheduled or due to special livery event), and now preventative action can be taken fleet-wide as a result.
 
StTim
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Re: QR finds composite cracks in early build A350

Sun Jan 03, 2021 10:27 pm

LAX772LR wrote:
Well, not news anyone would want, but hardly some kind of anomaly.... as cracking throughout fuselage, empennage, wings, internal engine parts, etc etc etc is nothing new for newly launched (or even some seasoned) models.

The important thing is that a maintenance regimen did its duty, and preemptively found these (whether scheduled or due to special livery event), and now preventative action can be taken fleet-wide as a result.


As you say this is normal and happens on all types of planes.
 
Boof02671
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Re: QR finds composite cracks in early build A350

Sun Jan 03, 2021 10:39 pm

Cracks are certainly not normal
 
wjcandee
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Re: QR finds composite cracks in early build A350

Sun Jan 03, 2021 10:48 pm

Boof02671 wrote:
Cracks are certainly not normal


It's always so interesting to me when perusing threads on a.net how the non-engineering people say things like "It's just cracks in the fuselage after 4 years. Perfectly normal. Perfectly safe."

And then the one guy in the thread who actually has decades of experience in Big Airline aircraft maintenance states the truth as clear as a bell.
 
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EMBSPBR
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Re: QR finds composite cracks in early build A350

Sun Jan 03, 2021 10:50 pm

StTim wrote:
LAX772LR wrote:
Well, not news anyone would want, but hardly some kind of anomaly.... as cracking throughout fuselage, empennage, wings, internal engine parts, etc etc etc is nothing new for newly launched (or even some seasoned) models.

The important thing is that a maintenance regimen did its duty, and preemptively found these (whether scheduled or due to special livery event), and now preventative action can be taken fleet-wide as a result.


As you say this is normal and happens on all types of planes.


Cracks on composites ?
Definitely not normal and no good thing !
 
Waterbomber2
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Re: QR finds composite cracks in early build A350

Sun Jan 03, 2021 10:51 pm

Definitely not normal, shear luck and coincidence that this was caught early.
Good job of the guys in SNN, nominees for the Airbus medal?

Long-term, we'll see if these all-CFRP fuselages really last as long as the aluminium ones.
The other day I was on a B789 and it had black repair spots all over its extrados. It looked pretty messy.
 
bigb
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Re: QR finds composite cracks in early build A350

Sun Jan 03, 2021 11:14 pm

wjcandee wrote:
Boof02671 wrote:
Cracks are certainly not normal


It's always so interesting to me when perusing threads on a.net how the non-engineering people say things like "It's just cracks in the fuselage after 4 years. Perfectly normal. Perfectly safe."

And then the one guy in the thread who actually has decades of experience in Big Airline aircraft maintenance states the truth as clear as a bell.


What else do you expect lol
 
MIflyer12
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Re: QR finds composite cracks in early build A350

Sun Jan 03, 2021 11:19 pm

LAX772LR wrote:
Well, not news anyone would want, but hardly some kind of anomaly.... as cracking throughout fuselage, empennage, wings, internal engine parts, etc etc etc is nothing new for newly launched (or even some seasoned) models.

The important thing is that a maintenance regimen did its duty, and preemptively found these (whether scheduled or due to special livery event), and now preventative action can be taken fleet-wide as a result.


If it took paint removal to find these, one has to wonder if the prescribed inspections are both effective and frequent enough. It will be interesting to see if:

1. this is a one-off

2. it's part of a bad batch of fuselages (size TBD)

3. it comes to be seen as regular aging of A350s
 
Weatherwatcher1
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Re: QR finds composite cracks in early build A350

Sun Jan 03, 2021 11:31 pm

LAX772LR wrote:
Well, not news anyone would want, but hardly some kind of anomaly.... as cracking throughout fuselage, empennage, wings, internal engine parts, etc etc etc is nothing new for newly launched (or even some seasoned) models.

The important thing is that a maintenance regimen did its duty, and preemptively found these (whether scheduled or due to special livery event), and now preventative action can be taken fleet-wide as a result.


Cracks are normal. It’s a good thing they were found. The structural inspection program always evolves as an airplane ages

What isn’t normal is an airline sending a plane back to Toulouse for repairs. Repairs are done by the airline or it’s MRO and reimbursed for warranty claims. AAB must be pretty upset to send the plane to France for repairs (and investigation?) by Airbus. Occasionally brand new airplanes go back to the Airbus/Boeing for repairs, but I can’t think of examples where a 4 year old A350 was sent back since Airbus can fly people out to the plane. Does anyone have examples of similar events?

Let’s hope that these cracks aren’t an early sign of the A350 facing similar cracks as the A380 does.
Last edited by Weatherwatcher1 on Sun Jan 03, 2021 11:58 pm, edited 4 times in total.
 
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JannEejit
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Re: QR finds composite cracks in early build A350

Sun Jan 03, 2021 11:32 pm

Was it's ground collision in 2018 likely to have played any part in this ?
 
Weatherwatcher1
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Re: QR finds composite cracks in early build A350

Sun Jan 03, 2021 11:53 pm

Waterbomber2 wrote:
Definitely not normal, shear luck and coincidence that this was caught early.
Good job of the guys in SNN, nominees for the Airbus medal?

Long-term, we'll see if these all-CFRP fuselages really last as long as the aluminium ones.
The other day I was on a B789 and it had black repair spots all over its extrados. It looked pretty messy.


What is an extrados? My first question would be if we are talking about structural cracks or lightning strike repairs.
 
Weatherwatcher1
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Re: QR finds composite cracks in early build A350

Sun Jan 03, 2021 11:55 pm

JannEejit wrote:
Was it's ground collision in 2018 likely to have played any part in this ?


It would be a bit odd in my opinion. The prior collision was on the stabilizer. While it is certainly possible that the collision could have stressed the fuselage and caused damage, I think it would be unusual for a ground collision to accelerate fatigue cracking on fuselage skin. It’s possible that the damage wasn’t found in 2018. If that is true, appropriate investigations would be appropriate regarding the procedures used to inspect the plane back then
Last edited by Weatherwatcher1 on Sun Jan 03, 2021 11:57 pm, edited 1 time in total.
 
Boof02671
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Re: QR finds composite cracks in early build A350

Sun Jan 03, 2021 11:55 pm

wjcandee wrote:
Boof02671 wrote:
Cracks are certainly not normal


It's always so interesting to me when perusing threads on a.net how the non-engineering people say things like "It's just cracks in the fuselage after 4 years. Perfectly normal. Perfectly safe."

And then the one guy in the thread who actually has decades of experience in Big Airline aircraft maintenance states the truth as clear as a bell.

I worked 20 years in aircraft maintenance for US Airways. Ask any mechanic, engineer, FAA or the NTSB cracks are certainly not normal and can cause a major catastrophe.

If a crack is found in a fuselage it has to measured, drill stopped an EO written to allow it to fly or not or be taken out of service for repair.

If allowed to fly it has to be inspected at every time interval in the EO
Guess you forgot about the Aloha accident?
 
wjcandee
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Re: QR finds composite cracks in early build A350

Mon Jan 04, 2021 12:00 am

Boof02671 wrote:
wjcandee wrote:
Boof02671 wrote:
Cracks are certainly not normal


It's always so interesting to me when perusing threads on a.net how the non-engineering people say things like "It's just cracks in the fuselage after 4 years. Perfectly normal. Perfectly safe."

And then the one guy in the thread who actually has decades of experience in Big Airline aircraft maintenance states the truth as clear as a bell.

I worked 20 years in aircraft maintenance for US Airways. Ask any mechanic, engineer, FAA or the NTSB cracks are certainly not normal and can cause a major catastrophe.

If a crack is found in a fuselage it has to measured, drill stopped an EO written to allow it to fly or not or be taken out of service for repair.

If allowed to fly it has to be inspected at every time interval in the EO
Guess you forgot about the Aloha accident?


I was actually saying that you were the person who was correct, that you had the decades of experience, and that you stated the truth clearly and efficiently.

You said cracks were not normal. I agree. They're bad. Potentially very very bad. And these were only found because the paint was taken off the airframe to apply a special livery, much earlier than normal.

I was agreeing with you, but I didn't say what I said as clearly as you said what you said. :smile: :smile:
Last edited by wjcandee on Mon Jan 04, 2021 12:01 am, edited 1 time in total.
 
Weatherwatcher1
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Re: QR finds composite cracks in early build A350

Mon Jan 04, 2021 12:02 am

Boof02671 wrote:
wjcandee wrote:
Boof02671 wrote:
Cracks are certainly not normal


It's always so interesting to me when perusing threads on a.net how the non-engineering people say things like "It's just cracks in the fuselage after 4 years. Perfectly normal. Perfectly safe."

And then the one guy in the thread who actually has decades of experience in Big Airline aircraft maintenance states the truth as clear as a bell.

I worked 20 years in aircraft maintenance for US Airways. Ask any mechanic, engineer, FAA or the NTSB cracks are certainly not normal and can cause a major catastrophe.

If a crack is found in a fuselage it has to measured, drill stopped an EO written to allow it to fly or not or be taken out of service for repair.

If allowed to fly it has to be inspected at every time interval in the EO
Guess you forgot about the Aloha accident?


It all depends on the size of the crack. There is plenty of secondary structure on an airplane that doesn’t see sophisticated non destructive tests in the maintenance program where cracks may go undetected. Primary structure has an extensive inspection program and any findings need to be addressed exactly as you said.

I have no doubt that Airbus and EASA will study and assess the cracks to determine if they are occurring based on the crack growth models that were originally created. If these cracks are beyond what was anticipated, we could see AD mandated repairs/modifications combined with an enhanced inspection program.
Last edited by Weatherwatcher1 on Mon Jan 04, 2021 12:09 am, edited 1 time in total.
 
wjcandee
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Re: QR finds composite cracks in early build A350

Mon Jan 04, 2021 12:06 am

And to further agree with what Boof02671 pointed out about all the documentation required when cracks are found and how they can lead to catastrophic issues, note this:

The painting contractor's people saw the cracks, knew they were not normal, and notified the manufacturer (and whomever else they had to notify).

The manufacturer sent its people to have a look, and they then decided to ferry the thing to Toulouse so a bunch of its people can look at it. (And, presumably, so the manufacturer can figure out all the ways that this is not its fault. :smile: )
 
Boof02671
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Re: QR finds composite cracks in early build A350

Mon Jan 04, 2021 12:09 am

wjcandee wrote:
And to further agree with what Boof02671 pointed out about all the documentation required when cracks are found and how they can lead to catastrophic issues, note this:

The painting contractor's people saw the cracks, knew they were not normal, and notified the manufacturer (and whomever else they had to notify).

The manufacturer sent its people to have a look, and they then decided to ferry the thing to Toulouse so a bunch of its people can look at it. (And, presumably, so the manufacturer can figure out all the ways that this is not its fault. :smile: )

And if it wasn’t for the plane going in for a repaint who knows when it if they would have been found before a catastrophe
 
Weatherwatcher1
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Re: QR finds composite cracks in early build A350

Mon Jan 04, 2021 12:11 am

Boof02671 wrote:
The Aloha fuselage ruptured caused the NTSB and the FAA enact the aging aircraft program


The aging aircraft program as key. As A350s are just starting to go through heavy maintenance visits, there will be many cracks found that will be analyzed as the aging aircraft program is built for the future. Aviation is a learning industry and I’d assume that flying the plane back to Toulouse will help asses the models and assumptions used when the airplane was designed
 
Antarius
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Re: QR finds composite cracks in early build A350

Mon Jan 04, 2021 12:16 am

Weatherwatcher1 wrote:
Boof02671 wrote:
The Aloha fuselage ruptured caused the NTSB and the FAA enact the aging aircraft program


The aging aircraft program as key. As A350s are just starting to go through heavy maintenance visits, there will be many cracks found that will be analyzed as the aging aircraft program is built for the future. Aviation is a learning industry and I’d assume that flying the plane back to Toulouse will help asses the models and assumptions used when the airplane was designed


No disagreement. But we should recognize that this was involving some luck to find. Had the aircraft not been stripped for a special livery, the problem may not have been found.

That said, we don't know if this is a one off or larger issue so no need to panic. It's clearly serious enough that the aircraft is headed back to TLS and that way it can be diagnosed.
 
zuckie13
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Re: QR finds composite cracks in early build A350

Mon Jan 04, 2021 12:18 am

My question is how much sooner did this get caught vs if the plane was not getting a special paint job?
 
Boof02671
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Re: QR finds composite cracks in early build A350

Mon Jan 04, 2021 12:18 am

Weatherwatcher1 wrote:
Boof02671 wrote:
The Aloha fuselage ruptured caused the NTSB and the FAA enact the aging aircraft program


The aging aircraft program as key. As A350s are just starting to go through heavy maintenance visits, there will be many cracks found that will be analyzed as the aging aircraft program is built for the future. Aviation is a learning industry and I’d assume that flying the plane back to Toulouse will help asses the models and assumptions used when the airplane was designed

All widebodies go in for an annual C-Check and HMV visit.
 
wjcandee
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Re: QR finds composite cracks in early build A350

Mon Jan 04, 2021 12:21 am

zuckie13 wrote:
My question is how much sooner did this get caught vs if the plane was not getting a special paint job?


The way to answer the question is to find out information that I don't have, specifically how often Qatar does a full-strip and repaint of its aircraft for cosmetic reasons. And then to figure out when the first maintenance check that would require a strip and inspection would be under the existing maintenance program. The sooner of those is when it would have been found.
 
mxaxai
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Re: QR finds composite cracks in early build A350

Mon Jan 04, 2021 12:21 am

Boof02671 wrote:
wjcandee wrote:
Boof02671 wrote:
Cracks are certainly not normal


It's always so interesting to me when perusing threads on a.net how the non-engineering people say things like "It's just cracks in the fuselage after 4 years. Perfectly normal. Perfectly safe."

And then the one guy in the thread who actually has decades of experience in Big Airline aircraft maintenance states the truth as clear as a bell.

I worked 20 years in aircraft maintenance for US Airways. Ask any mechanic, engineer, FAA or the NTSB cracks are certainly not normal and can cause a major catastrophe.

If a crack is found in a fuselage it has to measured, drill stopped an EO written to allow it to fly or not or be taken out of service for repair.

If allowed to fly it has to be inspected at every time interval in the EO
Guess you forgot about the Aloha accident?

Tiny cracks are "normal" in the sense that they occur inevitably and that the structure needs to tolerate them until they're detected in the next check. The smallest cracks are undetectable with common methods.

Once they're detected, cracks need to be assessed by maintenance and, if neccessary, repaired.

If cracks slip by undetected or grow faster than expected, they can cause a catastrophic failure. So it can be a major headache to find cracks prematurely, in unexpected places, or growing quickly.

But fundamentally, every single aircraft has a crack somewhere. Some are acceptable, some are not.

(A bit like the difference between benign tumors and cancer. You don't want either but one is tolerable - and common - while the other will kill you.)
 
wjcandee
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Re: QR finds composite cracks in early build A350

Mon Jan 04, 2021 12:22 am

Boof02671 wrote:
All widebodies go in for an annual C-Check and HMV visit.


That's a good point, which likely means that this aircraft had had several previous significant inspections without a full paint strip. And that those inspections didn't find these cracks.
 
xwb565
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Re: QR finds composite cracks in early build A350

Mon Jan 04, 2021 12:25 am

The oldest a350 A7-ALA has its C2 done at Doha and my understanding is nothing significant was found. There does appear to be a ground collision issue here as the original poster noted. Any immediate findings would have been communicated to operators by now and nothing has been heard of yet.
 
Antarius
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Re: QR finds composite cracks in early build A350

Mon Jan 04, 2021 12:32 am

xwb565 wrote:
The oldest a350 A7-ALA has its C2 done at Doha and my understanding is nothing significant was found. There does appear to be a ground collision issue here as the original poster noted. Any immediate findings would have been communicated to operators by now and nothing has been heard of yet.


A7-ALL would have had a C2 done as well by now? It's 4 years old.

The key question is whether this is specific to A7-ALL or was it only detected on A7-ALL due to the paint strip and therefore may be on A7-ALA and others, undetected thus far. Airbus will hopefully have the answer soon.
 
xwb565
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Re: QR finds composite cracks in early build A350

Mon Jan 04, 2021 12:36 am

Nothing can be ruled out but cracks showing up only on the primer and not the main paint would be strange ? Perhaps a composite expert here can answer?. ALA had the c2 done very recently so I doubt if ALL has undergone the same.
 
Cubsrule
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Re: QR finds composite cracks in early build A350

Mon Jan 04, 2021 12:51 am

Antarius wrote:
Weatherwatcher1 wrote:
Boof02671 wrote:
The Aloha fuselage ruptured caused the NTSB and the FAA enact the aging aircraft program


The aging aircraft program as key. As A350s are just starting to go through heavy maintenance visits, there will be many cracks found that will be analyzed as the aging aircraft program is built for the future. Aviation is a learning industry and I’d assume that flying the plane back to Toulouse will help asses the models and assumptions used when the airplane was designed


No disagreement. But we should recognize that this was involving some luck to find. Had the aircraft not been stripped for a special livery, the problem may not have been found.

That said, we don't know if this is a one off or larger issue so no need to panic. It's clearly serious enough that the aircraft is headed back to TLS and that way it can be diagnosed.


This is correct but remember that here “serious” may mean nothing more than “Airbus needs to understand better what’s going on.” It’s not like there are scads of 350s with known cracking issues (which is obviously a good thing).
 
CWL757
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Re: QR finds composite cracks in early build A350

Mon Jan 04, 2021 2:31 am

This is actually the 2nd A350 to be repainted, An A35K, F-WXXL (a test frame) went to VS as G-VDOT. No cracks found AFAIK.
 
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ElroyJetson
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Re: QR finds composite cracks in early build A350

Mon Jan 04, 2021 2:50 am

xwb565 wrote:
The oldest a350 A7-ALA has its C2 done at Doha and my understanding is nothing significant was found. There does appear to be a ground collision issue here as the original poster noted. Any immediate findings would have been communicated to operators by now and nothing has been heard of yet.



You make a lot of assumptions with no facts to back it up. Cracks developing in a four year old aircraft fuselage is never good. If the cracks were the result of a prior ground collision (pure speculation at this point), then the initial inspection after the collision was obviously poorly done. Maybe wait for some actual facts before saying there is nothing to see here. To me it sounds significant that this plane was sent to Toulouse. But until further information is released I will not speculate.
Last edited by ElroyJetson on Mon Jan 04, 2021 2:54 am, edited 1 time in total.
 
Ziyulu
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Re: QR finds composite cracks in early build A350

Mon Jan 04, 2021 2:54 am

Is it cracks in the paint?
 
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ElroyJetson
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Re: QR finds composite cracks in early build A350

Mon Jan 04, 2021 2:55 am

Ziyulu wrote:
Is it cracks in the paint?



The OP provided links. Per the links they were fuselage cracks. The aircraft will be ferried to TLS for repair. Beyond that who knows....
 
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Antaras
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Re: QR finds composite cracks in early build A350

Mon Jan 04, 2021 3:12 am

Any information from other early operators such as Vietnam Airlines and Finnair?
 
Antarius
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Re: QR finds composite cracks in early build A350

Mon Jan 04, 2021 3:19 am

Antaras wrote:
Any information from other early operators such as Vietnam Airlines and Finnair?


None. This is the first aircraft that has had this issue. We don't know if it's isolated to this frame, a broader issue with the type or an issue that's a result of something else.

Aircraft is going to be examined by Airbus in TLS. Until then, have to wait and see.

Personally not concerned yet. Not enough information.
 
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lightsaber
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Re: QR finds composite cracks in early build A350

Mon Jan 04, 2021 3:22 am

Antarius wrote:
Weatherwatcher1 wrote:
Boof02671 wrote:
The Aloha fuselage ruptured caused the NTSB and the FAA enact the aging aircraft program


The aging aircraft program as key. As A350s are just starting to go through heavy maintenance visits, there will be many cracks found that will be analyzed as the aging aircraft program is built for the future. Aviation is a learning industry and I’d assume that flying the plane back to Toulouse will help asses the models and assumptions used when the airplane was designed


No disagreement. But we should recognize that this was involving some luck to find. Had the aircraft not been stripped for a special livery, the problem may not have been found.

That said, we don't know if this is a one off or larger issue so no need to panic. It's clearly serious enough that the aircraft is headed back to TLS and that way it can be diagnosed.

It amazes me how many cracks are found by happenstance. e.g., QF engine failure found wing ceacks (IIRC bracket, but structural brackets), 738 pickle forks, how were the A320 wing cracks found? (I forgot) Now this.

An inspection regimen and a fix, as with the pickle forks, will be implemented. At first sign, I think a similar issue that is likely to cost about as much oer airframe as the pickle forks (I believe repairs are down to $50 k, but going from memory, so please correct me).

Interesting, not normal, but until EASA grounds more, I will wait for more information before a fire alarm. Note: I was too blase on the 787 battery fires, so my history at predicting the impact is.. poor.

Lightsaber
 
Wingtips56
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Re: QR finds composite cracks in early build A350

Mon Jan 04, 2021 3:39 am

How different is a crack in a composite hull versus a skin crack in a metal skin or more internal replaceable part? If a shallow crack, can it be dug out and filled? (I am not knowledgeable on these things, so be kind...) Or is it a bigger deal? I assume that such repairs are not a normal item for outstations or painting crews, hence the trip back to the factory. And, for due diligence, the OEM needs to know what's going on.
 
Antarius
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Re: QR finds composite cracks in early build A350

Mon Jan 04, 2021 3:45 am

lightsaber wrote:
Antarius wrote:
Weatherwatcher1 wrote:

The aging aircraft program as key. As A350s are just starting to go through heavy maintenance visits, there will be many cracks found that will be analyzed as the aging aircraft program is built for the future. Aviation is a learning industry and I’d assume that flying the plane back to Toulouse will help asses the models and assumptions used when the airplane was designed


No disagreement. But we should recognize that this was involving some luck to find. Had the aircraft not been stripped for a special livery, the problem may not have been found.

That said, we don't know if this is a one off or larger issue so no need to panic. It's clearly serious enough that the aircraft is headed back to TLS and that way it can be diagnosed.

It amazes me how many cracks are found by happenstance. e.g., QF engine failure found wing ceacks (IIRC bracket, but structural brackets), 738 pickle forks, how were the A320 wing cracks found? (I forgot) Now this.

An inspection regimen and a fix, as with the pickle forks, will be implemented. At first sign, I think a similar issue that is likely to cost about as much oer airframe as the pickle forks (I believe repairs are down to $50 k, but going from memory, so please correct me).

Interesting, not normal, but until EASA grounds more, I will wait for more information before a fire alarm. Note: I was too blase on the 787 battery fires, so my history at predicting the impact is.. poor.

Lightsaber


Hindsight is 20/20. However, it's risky to base any decision on a single data point. I was (in hindsight) blaze about the MAX issue too. One data point is too few to know if it's an anomaly or trend.

I expect we'll find out soon if there is a second aircraft like A7-ALL or none at all. That's still not enough to be sure, but at least 2 points allows a line.
 
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lightsaber
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Re: QR finds composite cracks in early build A350

Mon Jan 04, 2021 3:54 am

Antarius wrote:
lightsaber wrote:
Antarius wrote:

No disagreement. But we should recognize that this was involving some luck to find. Had the aircraft not been stripped for a special livery, the problem may not have been found.

That said, we don't know if this is a one off or larger issue so no need to panic. It's clearly serious enough that the aircraft is headed back to TLS and that way it can be diagnosed.

It amazes me how many cracks are found by happenstance. e.g., QF engine failure found wing ceacks (IIRC bracket, but structural brackets), 738 pickle forks, how were the A320 wing cracks found? (I forgot) Now this.

An inspection regimen and a fix, as with the pickle forks, will be implemented. At first sign, I think a similar issue that is likely to cost about as much oer airframe as the pickle forks (I believe repairs are down to $50 k, but going from memory, so please correct me).

Interesting, not normal, but until EASA grounds more, I will wait for more information before a fire alarm. Note: I was too blase on the 787 battery fires, so my history at predicting the impact is.. poor.

Lightsaber


Hindsight is 20/20. However, it's risky to base any decision on a single data point. I was (in hindsight) blaze about the MAX issue too. One data point is too few to know if it's an anomaly or trend.

I expect we'll find out soon if there is a second aircraft like A7-ALL or none at all. That's still not enough to be sure, but at least 2 points allows a line.

We are in agreement. Inspections will be ordered (ultrasound? maybe xray? Ok, I'm speculating) and off that data, a plan will be formulated.

Since CFRP doesn't corrode, it is cycles or hours, ir just a manufacturing defect that did this (a la picklefork). So, how many cycles and hours?

Was this a long haul airframe? Or was this doing DOH to India 4x a day? (I doubt either) It is quite possible to crack CFRP when drilling, so it this rivit cracks (different mechanism, but analogous to the Titanic's construction) or a bizarre CFRP fatigue?

Ok, I've come up with sux other mechanisms, so as to not freak everyone from flying, I'll stop now. :spin:

Lightsaber
 
ABpositive
Posts: 244
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Re: QR finds composite cracks in early build A350

Mon Jan 04, 2021 4:00 am

Wingtips56 wrote:
How different is a crack in a composite hull versus a skin crack in a metal skin or more internal replaceable part? If a shallow crack, can it be dug out and filled? (I am not knowledgeable on these things, so be kind...) Or is it a bigger deal? I assume that such repairs are not a normal item for outstations or painting crews, hence the trip back to the factory. And, for due diligence, the OEM needs to know what's going on.


I think this is the best question in the thread! Treating composite cracks is very different from metal. For one, you don't drill - this makes things worse. You need to check if the carbon fibers are breaking (this is serious and direction of forces acting on fuselage may need to be revisited) or if the crack is only occurring in the filler materials (easy fix and much less critical).

PS. While my experience is from cycling, that industry has gone through very similar change.
 
alasizon
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Re: QR finds composite cracks in early build A350

Mon Jan 04, 2021 4:27 am

The initial source claims that the worst cracks are in the stab which makes sense when it comes to the ground collision theory however it mentions multiple cracks including some not on the stab area. By no means am I super knowledgeable when it comes to CFRP but is it possible for an improperly patched repair on CFRP to cause additional stress on other areas of the fuselage that could lead to premature cracking?
 
Weatherwatcher1
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Re: QR finds composite cracks in early build A350

Mon Jan 04, 2021 4:31 am

Boof02671 wrote:
Weatherwatcher1 wrote:
Boof02671 wrote:
The Aloha fuselage ruptured caused the NTSB and the FAA enact the aging aircraft program


The aging aircraft program as key. As A350s are just starting to go through heavy maintenance visits, there will be many cracks found that will be analyzed as the aging aircraft program is built for the future. Aviation is a learning industry and I’d assume that flying the plane back to Toulouse will help asses the models and assumptions used when the airplane was designed

All widebodies go in for an annual C-Check and HMV visit.


I’m not sure what airlines you are referring to. C-Checks range from 12 to 36 months depending on the MPD intervals and the individual airline’s maintenance program. Additionally structural inspections are typically cycle based. Certain areas are looked at more frequently. Some areas may not be inspected in the first 10-12 years of service with more intensive inspections.
 
dynamo12
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Re: QR finds composite cracks in early build A350

Mon Jan 04, 2021 5:17 am

ElroyJetson wrote:
xwb565 wrote:
The oldest a350 A7-ALA has its C2 done at Doha and my understanding is nothing significant was found. There does appear to be a ground collision issue here as the original poster noted. Any immediate findings would have been communicated to operators by now and nothing has been heard of yet.



You make a lot of assumptions with no facts to back it up. Cracks developing in a four year old aircraft fuselage is never good. If the cracks were the result of a prior ground collision (pure speculation at this point), then the initial inspection after the collision was obviously poorly done. Maybe wait for some actual facts before saying there is nothing to see here. To me it sounds significant that this plane was sent to Toulouse. But until further information is released I will not speculate.


The aircraft WILL age. That means there WILL be cracks. Airbus has an aging aircraft model. These cracks may update it or not. They could be terrible. Heads up - there WILL be cracks on even a 4 year old plane if it is new and no models have been validated. But a crack in a toilet paper holder on an interior bathroom that is not structural is MUCH less serious than fuselage cracks, which are in turn likely less severe then cracking elsewhere. May be be hard to generalize from a plane with a collision history.

Anyways, I think you are also jumping to total alarm to early without enough facts. There is a worry about composites and longevity - I do think story is still to come there. And this could be a bad sign.
 
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ElroyJetson
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Re: QR finds composite cracks in early build A350

Mon Jan 04, 2021 5:50 am

dynamo12 wrote:
ElroyJetson wrote:
xwb565 wrote:
The oldest a350 A7-ALA has its C2 done at Doha and my understanding is nothing significant was found. There does appear to be a ground collision issue here as the original poster noted. Any immediate findings would have been communicated to operators by now and nothing has been heard of yet.



You make a lot of assumptions with no facts to back it up. Cracks developing in a four year old aircraft fuselage is never good. If the cracks were the result of a prior ground collision (pure speculation at this point), then the initial inspection after the collision was obviously poorly done. Maybe wait for some actual facts before saying there is nothing to see here. To me it sounds significant that this plane was sent to Toulouse. But until further information is released I will not speculate.


The aircraft WILL age. That means there WILL be cracks. Airbus has an aging aircraft model. These cracks may update it or not. They could be terrible. Heads up - there WILL be cracks on even a 4 year old plane if it is new and no models have been validated. But a crack in a toilet paper holder on an interior bathroom that is not structural is MUCH less serious than fuselage cracks, which are in turn likely less severe then cracking elsewhere. May be be hard to generalize from a plane with a collision history.

Anyways, I think you are also jumping to total alarm to early without enough facts. There is a worry about composites and longevity - I do think story is still to come there. And this could be a bad sign.



I expressed no alarm at all. None. I will wait for the facts. I simply said cracks in the fuselage of a 4 year old aircraft is never good. But as for this particular aircraft I know no more than you. It may or may not be a serious issue. We will find out eventually. With the MAX issues and problems with other aircraft I think it's best to to neither say everything thing is fine, no problems, or alternately panic and say the sky is falling. Right now folks need to chill and wait for the facts imho. That is my only point.
 
Blerg
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Re: QR finds composite cracks in early build A350

Mon Jan 04, 2021 5:57 am

Was the plane safe to fly on? I mean what would have happened if they didn't plan to repaint it?
 
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Francoflier
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Re: QR finds composite cracks in early build A350

Mon Jan 04, 2021 5:59 am

It's really impossible to know how this will turn out at this stage.

I'm guessing anything from "a minor defect affecting early frames resolved with maintenance schedule modifications and an AD" to "serious and expensive consequences which will affect the airframe's lifespan" and anything in between.

The only thing I got from that is how good the 350 looks without the racoon mask on that picture... I just wish someone will stop painting it on already. Don't buy the marketing bullshit from Airbus (thermal stabilization blahblah) and just do it. :wink2:
 
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Pythagoras
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Re: QR finds composite cracks in early build A350

Mon Jan 04, 2021 6:37 am

So here are the possible types of cracks that one might see:
- crack due to an accidental impact damage event, typically 0.50" before visible on the surface, or an internal crack in a radius detail on a frame, typically 1.0" long before visible
- an internal interlaminar crack in a radius detail which is not detectable visually and very difficult to detect with Non Destructive Inspection.
- a fracture of a component, e.g. a stiffener, frame, or stringer element due to a major damage event
- a dis-bond between co-cured or co-bonded elements
- failure in the protective coating which might manifest itself as surface cracks, excessive paint application can lead to mud-cracking which over time can penetrate into the laminate. Alternatively, cracks might occur should there be a lightning protection system added and thermal cycling causes degradation to the surface.

Surface manufacturing flaws, e.g. wrinkles, gaps between plies, can appear to be cracks but would have no structural consequences.

The typical fatigue crack seen in metals emanating from a fastener or stress concentration can only happens if there is an isolated overload event.
 
wjcandee
Posts: 10810
Joined: Mon Jun 05, 2000 12:50 am

Re: QR finds composite cracks in early build A350

Mon Jan 04, 2021 7:22 am

FWIW, guys, this is a fascinating thread, with a lot of knowledge being brought to bear and a lot of clear explanations of stuff. (And everyone is basically being nice, which makes it much more readable.) Thanks from this reader!
 
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Antaras
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Re: QR finds composite cracks in early build A350

Mon Jan 04, 2021 8:10 am

Antarius wrote:
Antaras wrote:
Any information from other early operators such as Vietnam Airlines and Finnair?


None. This is the first aircraft that has had this issue. We don't know if it's isolated to this frame, a broader issue with the type or an issue that's a result of something else.

Aircraft is going to be examined by Airbus in TLS. Until then, have to wait and see.

Personally not concerned yet. Not enough information.

Blerg wrote:
Was the plane safe to fly on? I mean what would have happened if they didn't plan to repaint it?

If the problem can only be found by repainting then it could be a serious problem, especially with carriers using dark-scheme livery like VN making it hard to find cracks on maintenance.
No guarantee that the problem won't occur on any A350 airframes else, especially the early-built airframes.

Don't know if Airbus would suggest the early operator repaint the aircraft just to have a clear check on the fuselage?!
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