Airliners.net

So just hearing from a Delta mechanic that a Delta A350 suffered wing delamination during a tire burst that sent rubber up to the wing during a landing at HSV. The mechanic described the event as similar to the Concorde except the phase was during landing instead of takeoff (also no causing debris and certainly no fire resulting). While tires do burst from time to time, the problem here is that the mechanic is saying that for the composite material that the repair going forward isn't that clear for the wing which may cause issues for future events.

I couldn't find any specific mentioning of this problem in the "in service thread" or other mention of this incident. I can't site a source but imagined that maybe some spotters had some pics of the aircraft in question (was not able to find out tail number though). Other than this event, what insight has there been given into handling FOD for composite aircraft structures? I imagine this would also include the likes of the 787 also but I'm not familiar with the differences in 787/A350 structure/repair insight for composites.

Concordski wrote:

So just hearing from a Delta mechanic that a Delta A350 suffered wing delamination during a tire burst that sent rubber up to the wing during a landing at HSV. The mechanic described the event as similar to the Concorde except the phase was during landing instead of takeoff (also no causing debris and certainly no fire resulting). While tires do burst from time to time, the problem here is that the mechanic is saying that for the composite material that the repair going forward isn't that clear for the wing which may cause issues for future events.

I couldn't find any specific mentioning of this problem in the "in service thread" or other mention of this incident. I can't site a source but imagined that maybe some spotters had some pics of the aircraft in question (was not able to find out tail number though). Other than this event, what insight has there been given into handling FOD for composite aircraft structures? I imagine this would also include the likes of the 787 also but I'm not familiar with the differences in 787/A350 structure/repair insight for composites.

This event occurred during a touch and go in CVG, but nonetheless it's a pretty big deal, I noticed some folks from Airbus were having a look at it at the TOC pad. This frame was supposed to be doing a couple non rev domestic runs on west coast in a few weeks and then doing an air to air photo shoot, and I believe all of that is in jeopardy.

Hopefully 3501 will pick up the slack.

Hopefully this will lead DL into canceling A350s finally and ordering the 747-8i to properly serve DTW and stop the hub closure.


Seriously though, is this the first delamination of a 787/A350 wing? I think I read in other threads that composites were going to be easier to and cheaper to repair than the old materials...

A jetstar 787 had a flap issue recently caused by tire debris... Interesting times for the new composite birds but hopefully the aircraft will be back in the air soon.

There are many things still to learn about these largely composite frames. Boeing learnt sheds loads when they repaired the ET bird on the ground at Heathrow.

Each case of ramp rash can throw up unexpected issues.

Larger incidents such as this one again new issues to solve and become part of the standard armoury.

I am actually more concerned about two aspects.

One recycling a plane at end of life and also what shards, particles etc will be released in a crash and how will that alter survivability.

Tire damage to composite structure can cause different damage than to alumnimum structure. The A350 and 787 both have intensive inspections required for thrown tire treads.

Airbus should have this repaired quickly as their experience with composites goes right back to the A300. They introduced them as part of major structures like the tailplane quite early on.

If anything it'll be a good learning experience for the DL maintenance crews.

Linking the incident to the Concorde crash is really a stretch, would you do that for the probably thousands of incidents where a tire burst and slightly damaged a wing ?

In the case of Concorde the damage was massive, with a shockwave in the wing causing even more damage, something probably not possible in the A350 wing under any circumstance.

Very alarmist post opening post.

Let me guess the delamination was the gel coat ?

Aesma wrote:

Linking the incident to the Concorde crash is really a stretch, would you do that for the probably thousands of incidents where a tire burst and slightly damaged a wing ?

In the case of Concorde the damage was massive, with a shockwave in the wing causing even more damage, something probably not possible in the A350 wing under any circumstance.

This is a funny statement. "probably not possible in the A350 wing under any circumstance., That is a stretch.

Take the case of the F-16 bird strike proof canopy. I flew the plane for years and we lost a few to the unknown until a interesting accident. The canopy absorbed a turkey vulture and the canopy did not shatter however the "shockwave" flexed the canopy enough it shattered the HUD and caused severe injury to the pilot. Less than a year later 16 based at homestead with the Makos went down due to a bird strike because it broke the pilots neck after hitting a turkey vulture. The plane was at 500ft and 480kts in southern Florida in the mid 90s. His wingman saw the impact and the canopy stayed intact but the plane nosed over slightly and it took about 10sec to hit the ground . Wing man was trying to radio lead but no response. The investigation showed thru the HUD tape the bird impact until ground contact. The audio confirmed his wingmans radio calls with no response. No attempted ejection.

Piper had build a great series of aircraft in the 60s and the Pa-23-250 Aztec is the subject of the next "shockwave" issue.

In 1972 the Piper lock haven plant flooded. The airframes damaged by flooding of the factory were donated to NASA. The planes were put on a "swing" device to test the integrity of the plane at impact. The planes were swung to impact the ground at many angles. As the impact angle increased the films showed a unique situtations. As the plane hit at roughly 30 degrees nose low, the impact would literally flex the plane to the point it would crush all the ouccupents where the plane flexed , then popped back to normal. All the crash test dummies had simulated injuries to a broken neck.all the windows would pop out of the airframes that had Windows. Many airframes were tested and proved the issue. The PA-23 fuselage is very unique too as it was a steel tube airframe with a aluminum covering. . The Navajo had similar issues but that airframe has no steel tube structure. NTSB noted in a few light plane crashes with deaths were unusual as the plane after impact looked intact , normal and complete except the Windows were popped out and the passengers were all dead. These accidents prompted the investigation when the Piper planes became available. Many YouTube videos d aviation week magazine articles on this.

So to sum it up, " probably not possible in the A350 wing under any circumstance." Is incorrect. Flex "shockwave" is possible under every circumstance.

It's not a B vs A thing, it's something tested and proven it can't happen with proof, or it is possible.

I agree the title of the thread has the drama but your statement without proof is incorrect . Very interesting research. Do some investigation to better understand the issue.

Cheers

NDI & scarf-repair I would assume, if it did infact delaminate an area. Typically, remove additional layers to get beyond the damaged surface, reapply the carbon fiber and resin, vacuum-bag it and cook it - overly simplified. Ive seen it done several times throughout the years and it's a skill in its own, pretty amazing too because you would never know there was even damage there.

What's a gel coat?

AirlineCritic wrote:

What's a gel coat?

It's what my girlfriend gets on her nails to protect and enhance the color. Actually, on a composite aircraft or marine structure, it's used for basically the same purpose.

AirlineCritic wrote:

What's a gel coat?

That is the colored heavily filled non tack resin you apply to a (polished surface ) female mold before
you start to lay the structural fiber and (polyester-)resin stuff.

For the final product it is the visible "nice" cosmetic outside, no further coatings.

IMU structural (epoxy resin) CFRP pieces are done without gel coat.
You later add various primer coats and the final varnish layer(s).

Sancho99504 wrote:

Hopefully this will lead DL into canceling A350s finally and ordering the 747-8i to properly serve DTW and stop the hub closure.


Seriously though, is this the first delamination of a 787/A350 wing? I think I read in other threads that composites were going to be easier to and cheaper to repair than the old materials...

Cancel a 350 order due to one incident, and in favour of the 748?!? Probably not...

Starlionblue wrote:

Sancho99504 wrote:

Hopefully this will lead DL into canceling A350s finally and ordering the 747-8i to properly serve DTW and stop the hub closure.

Seriously though, is this the first delamination of a 787/A350 wing? I think I read in other threads that composites were going to be easier to and cheaper to repair than the old materials...

Cancel a 350 order due to one incident, and in favour of the 748?!? Probably not...

You do realize he was being sarcastic?

Back to the topic, will the repair add any weight to the area? Will it need additional inspection during routine maintenance?

Do we have any photos? In the many tire bursts that I've witnessed on aircraft, it was mainly the t/e flaps that got damaged. If the honey comb structure wasn't too severely damaged, the plastics guys would simply pot the dents till the next hangar visit. I think there was one incident where a tank access panel got damaged.

akelley728 wrote:

Starlionblue wrote:

Sancho99504 wrote:

Hopefully this will lead DL into canceling A350s finally and ordering the 747-8i to properly serve DTW and stop the hub closure.

Seriously though, is this the first delamination of a 787/A350 wing? I think I read in other threads that composites were going to be easier to and cheaper to repair than the old materials...

Cancel a 350 order due to one incident, and in favour of the 748?!? Probably not...

You do realize he was being sarcastic?

Back to the topic, will the repair add any weight to the area? Will it need additional inspection during routine maintenance?

I actually did not realise he was being sarcastic.

Starlionblue wrote:

akelley728 wrote:

Starlionblue wrote:

Cancel a 350 order due to one incident, and in favour of the 748?!? Probably not...

You do realize he was being sarcastic?

Back to the topic, will the repair add any weight to the area? Will it need additional inspection during routine maintenance?

I actually did not realise he was being sarcastic.

I was making a jab at a forum member that believes the A350 replacing the 744 is Delta's way of screwing over the DTW hub.....followed by a question that started with "In all seriousness though,"

Sancho99504 wrote:

Starlionblue wrote:

akelley728 wrote:

You do realize he was being sarcastic?

Back to the topic, will the repair add any weight to the area? Will it need additional inspection during routine maintenance?

I actually did not realise he was being sarcastic.

I was making a jab at a forum member that believes the A350 replacing the 744 is Delta's way of screwing over the DTW hub.....followed by a question that started with "In all seriousness though,"

Sorry!

Starlionblue wrote:

Sancho99504 wrote:

Starlionblue wrote:

I actually did not realise he was being sarcastic.

I was making a jab at a forum member that believes the A350 replacing the 744 is Delta's way of screwing over the DTW hub.....followed by a question that started with "In all seriousness though,"

Sorry!

No biggie



I'm still curious as to what the process is and how long this airplane will be out of commission.

Without sounding completely clueless, what exactly is a delamination? Is it exactly as it sounds? Something similar to a stock car windshield, where you just peal a layer off to essentially give a clean view?

Sancho99504 wrote:

Without sounding completely clueless, what exactly is a delamination? Is it exactly as it sounds? Something similar to a stock car windshield, where you just peal a layer off to essentially give a clean view?

In essence, almost.

Composite materials (carbon fiber (CF) in this case) are made up of layers of substrate bonded together with an adhesive. The CF strips are the substrate here, and they are bonded with a heat-cured resin. When they delaminate, the resin bonds break, allowing the layers to separate. This has the potential to weaken the whole structure.

Google turns up this pretty good picture of delaminated CF.

When did this happen? I saw it in ATL on Saturday 9th Sept in the afternoon.

I don't get it, N501DN is in DTW and has been there since flying back from NRT on the 08/28/17 and N502DN has been in ATL since the 09/06/17 after flying from DTW via CVG. If this incident happened at HSV then it couldn't of been to bad considering they flew it up to DTW then a few hour later flew I back to ATL resuming the touch and go's at CVG on the way back.

reltney wrote:

Aesma wrote:

Linking the incident to the Concorde crash is really a stretch, would you do that for the probably thousands of incidents where a tire burst and slightly damaged a wing ?

In the case of Concorde the damage was massive, with a shockwave in the wing causing even more damage, something probably not possible in the A350 wing under any circumstance.

This is a funny statement. "probably not possible in the A350 wing under any circumstance., That is a stretch.

Take the case of the F-16 bird strike proof canopy. I flew the plane for years and we lost a few to the unknown until a interesting accident. The canopy absorbed a turkey vulture and the canopy did not shatter however the "shockwave" flexed the canopy enough it shattered the HUD and caused severe injury to the pilot. Less than a year later 16 based at homestead with the Makos went down due to a bird strike because it broke the pilots neck after hitting a turkey vulture. The plane was at 500ft and 480kts in southern Florida in the mid 90s. His wingman saw the impact and the canopy stayed intact but the plane nosed over slightly and it took about 10sec to hit the ground . Wing man was trying to radio lead but no response. The investigation showed thru the HUD tape the bird impact until ground contact. The audio confirmed his wingmans radio calls with no response. No attempted ejection.

Piper had build a great series of aircraft in the 60s and the Pa-23-250 Aztec is the subject of the next "shockwave" issue.

In 1972 the Piper lock haven plant flooded. The airframes damaged by flooding of the factory were donated to NASA. The planes were put on a "swing" device to test the integrity of the plane at impact. The planes were swung to impact the ground at many angles. As the impact angle increased the films showed a unique situtations. As the plane hit at roughly 30 degrees nose low, the impact would literally flex the plane to the point it would crush all the ouccupents where the plane flexed , then popped back to normal. All the crash test dummies had simulated injuries to a broken neck.all the windows would pop out of the airframes that had Windows. Many airframes were tested and proved the issue. The PA-23 fuselage is very unique too as it was a steel tube airframe with a aluminum covering. . The Navajo had similar issues but that airframe has no steel tube structure. NTSB noted in a few light plane crashes with deaths were unusual as the plane after impact looked intact , normal and complete except the Windows were popped out and the passengers were all dead. These accidents prompted the investigation when the Piper planes became available. Many YouTube videos d aviation week magazine articles on this.

So to sum it up, " probably not possible in the A350 wing under any circumstance." Is incorrect. Flex "shockwave" is possible under every circumstance.

It's not a B vs A thing, it's something tested and proven it can't happen with proof, or it is possible.

I agree the title of the thread has the drama but your statement without proof is incorrect . Very interesting research. Do some investigation to better understand the issue.

Cheers

I think I am missing something here...do you mean a shock wave as in compression force from the gas...atmosphere...causing the damage/death? Your text seems to imply injuries that happen in water when a concussive wave strikes objects in said water...and for the pilot of the F-16...did the bird strike the side of the canopy? I would think the head rest/stop built into the seat would stop too much cranial travel....like that used in auto racing.

bhill wrote:

reltney wrote:

Aesma wrote:

Linking the incident to the Concorde crash is really a stretch, would you do that for the probably thousands of incidents where a tire burst and slightly damaged a wing ?

In the case of Concorde the damage was massive, with a shockwave in the wing causing even more damage, something probably not possible in the A350 wing under any circumstance.

This is a funny statement. "probably not possible in the A350 wing under any circumstance., That is a stretch.

Take the case of the F-16 bird strike proof canopy. I flew the plane for years and we lost a few to the unknown until a interesting accident. The canopy absorbed a turkey vulture and the canopy did not shatter however the "shockwave" flexed the canopy enough it shattered the HUD and caused severe injury to the pilot. Less than a year later 16 based at homestead with the Makos went down due to a bird strike because it broke the pilots neck after hitting a turkey vulture. The plane was at 500ft and 480kts in southern Florida in the mid 90s. His wingman saw the impact and the canopy stayed intact but the plane nosed over slightly and it took about 10sec to hit the ground . Wing man was trying to radio lead but no response. The investigation showed thru the HUD tape the bird impact until ground contact. The audio confirmed his wingmans radio calls with no response. No attempted ejection.

Piper had build a great series of aircraft in the 60s and the Pa-23-250 Aztec is the subject of the next "shockwave" issue.

In 1972 the Piper lock haven plant flooded. The airframes damaged by flooding of the factory were donated to NASA. The planes were put on a "swing" device to test the integrity of the plane at impact. The planes were swung to impact the ground at many angles. As the impact angle increased the films showed a unique situtations. As the plane hit at roughly 30 degrees nose low, the impact would literally flex the plane to the point it would crush all the ouccupents where the plane flexed , then popped back to normal. All the crash test dummies had simulated injuries to a broken neck.all the windows would pop out of the airframes that had Windows. Many airframes were tested and proved the issue. The PA-23 fuselage is very unique too as it was a steel tube airframe with a aluminum covering. . The Navajo had similar issues but that airframe has no steel tube structure. NTSB noted in a few light plane crashes with deaths were unusual as the plane after impact looked intact , normal and complete except the Windows were popped out and the passengers were all dead. These accidents prompted the investigation when the Piper planes became available. Many YouTube videos d aviation week magazine articles on this.

So to sum it up, " probably not possible in the A350 wing under any circumstance." Is incorrect. Flex "shockwave" is possible under every circumstance.

It's not a B vs A thing, it's something tested and proven it can't happen with proof, or it is possible.

I agree the title of the thread has the drama but your statement without proof is incorrect . Very interesting research. Do some investigation to better understand the issue.

Cheers

I think I am missing something here...do you mean a shock wave as in compression force from the gas...atmosphere...causing the damage/death? Your text seems to imply injuries that happen in water when a concussive wave strikes objects in said water...and for the pilot of the F-16...did the bird strike the side of the canopy? I would think the head rest/stop built into the seat would stop too much cranial travel....like that used in auto racing.

I understood it that the canopy distorted, and passed it's distortion to the HUD, which then impacted the pilot - the pilot was how the force was dissipated...

Delta's statement on the matter:


https://twitter.com/FlyingHighRyan/stat ... 6035701760

When they say 'the aircraft is flying to...' does this mean the incident aircraft?

I think the tire incident was with the second aircraft which is still in ATL after a week now... However it's probably safe to assume its not a very serious repair if they are confident of starting service to NRT since that would require two aircraft... There was a rumor on a blog that the first aircraft also had a run in with ground equipment. All regular stuff but since it's DL's first a350s it is bound to attract attention. Perhaps 777mech will update us on the state of the tire burst repair?

Why is everyone talking about composite wings like it's something new? Hasn't Airbus had compositve wings since 1988 in A320? That's... almost 30 years ago. And why are we discussing the words of some anonymous mechanic like it's an official statement from a scientific lab?

wjcandee wrote:

AirlineCritic wrote:

What's a gel coat?

It's what my girlfriend gets on her nails to protect and enhance the color. Actually, on a composite aircraft or marine structure, it's used for basically the same purpose.

ROTFL.

Does your girlfriend mix epoxy and track the lot# and expiration date? But yeah.. same process and about as big a deal.

Very alarmist post. About as alarmist as early anti-stressed skin newspaper articles. I trust CFRP more as the knockdown factors are rediculously conservative.

Lightsaber

lightsaber wrote:

Does your girlfriend mix epoxy and track the lot# and expiration date?

Lightsaber

Hell yeah she does. They start scurrying inside YoYo Nails as soon as she appears in the doorway. But she tips well...

[quote="BREECH"]Why is everyone talking about composite wings like it's something new? Hasn't Airbus had compositve wings since 1988 in A320? [quote]

Parts of the wing are composite (spoilers, flaps, etc) but the main structure of the wing is not.

7BOEING7 wrote:

Parts of the wing are composite (spoilers, flaps, etc) but the main structure of the wing is not.

Is it now? Is it fully composite, including all those whatevers inside?

Was this N502DN? If so, does that have anything to do with why it's been at ATL since the 6th?

502dn has shown up on fr24 on the ground at ATL after more than two weeks... Hopefully any issue is now fixed and the bird is ready to head back into the air....

Here's a photo of N501DN, taken today. Aircraft sits on the ground with no activity around it.


https://www.reddit.com/r/aviation/comme ... o_see_how/

I think that is 501 at DTW

I heard somewhere that Delta's 2nd a350 was hit by a ground vehicle, is this true? Couldn't find any news reports on it.
Also I think Delta would much rather screw us over here at msp than those at detriot..

502 is back in the air...

lightningzap wrote:

Also I think Delta would much rather screw us over here at msp than those at detriot..

Serious question here just for my enlightenment: what would Delta have to do to have such an impact? Thanks

Moe

BREECH wrote:

Why is everyone talking about composite wings like it's something new? Hasn't Airbus had compositve wings since 1988 in A320? That's... almost 30 years ago.

No. The A320 has aluminum main wing structure. The A350 is the first Airbus airliner with CFRP wing main structure. Only the military A400 was earlier.

All reasonably modern airliners have various composites (glassfibre, carbon fibre, Kevlar) on the wings, (also on the wings), such as flaps, ailerons, and various non-structural panels. And certainly winglets. But that's something else.

Only the B787 and A350 are large airliners with what we normally will call "composite wings".

But it is nothing really new. The new thing, which made the B787 and A350 possible, was robotic layup of such large structures replacing hand work as done on many previous military planes. Robotic layup made such large structures economically viable to produce. Hand made as for instance the B-2 bomber was prohibitively expensive.

prebennorholm wrote:

Only the B787 and A350 are large airliners with what we normally will call "composite wings".

The A380 wing skins are multilayer laminated AL pieces. Another kind of composite

502 this morning at CVG

http://pbs.twimg.com/media/DKpurKYWsAE5Gre.jpg

Is that a reflection on the left wing underside or a composite repair?

aeromoe wrote:

lightningzap wrote:

Also I think Delta would much rather screw us over here at msp than those at detriot..

Serious question here just for my enlightenment: what would Delta have to do to have such an impact? Thanks

Moe

could be due to proximity of Detroit. They're downsizing a bit

prebennorholm wrote:

No. The A320 has aluminum main wing structure. The A350 is the first Airbus airliner with CFRP wing main structure. Only the military A400 was earlier.

All reasonably modern airliners have various composites (glassfibre, carbon fibre, Kevlar) on the wings, (also on the wings), such as flaps, ailerons, and various non-structural panels. And certainly winglets. But that's something else.

Only the B787 and A350 are large airliners with what we normally will call "composite wings".

But it is nothing really new. The new thing, which made the B787 and A350 possible, was robotic layup of such large structures replacing hand work as done on many previous military planes. Robotic layup made such large structures economically viable to produce. Hand made as for instance the B-2 bomber was prohibitively expensive.

Whoa, whoa, whoa! Wait a minute. You mean their wings are made ENTIRELY of plastic?! No metal structure AT ALL!? What about connections? Rivets? Fasteners? Or just glue? How do you attach movable parts, like flaps, slats and whatnot? Plastic to plastic seems a bit... flimsy, no?

BREECH wrote:

prebennorholm wrote:

No. The A320 has aluminum main wing structure. The A350 is the first Airbus airliner with CFRP wing main structure. Only the military A400 was earlier.

All reasonably modern airliners have various composites (glassfibre, carbon fibre, Kevlar) on the wings, (also on the wings), such as flaps, ailerons, and various non-structural panels. And certainly winglets. But that's something else.

Only the B787 and A350 are large airliners with what we normally will call "composite wings".

But it is nothing really new. The new thing, which made the B787 and A350 possible, was robotic layup of such large structures replacing hand work as done on many previous military planes. Robotic layup made such large structures economically viable to produce. Hand made as for instance the B-2 bomber was prohibitively expensive.

Whoa, whoa, whoa! Wait a minute. You mean their wings are made ENTIRELY of plastic?! No metal structure AT ALL!? What about connections? Rivets? Fasteners? Or just glue? How do you attach movable parts, like flaps, slats and whatnot? Plastic to plastic seems a bit... flimsy, no?

It's not really "plastic". The major structural bits like the spars and skins are composite. There's still plenty of metal in the wings. For example the leading edges are metal.



The inside of the engine inlets is also composite except for the leading edge. They have this very futuristic looking grooved black surface.

The unanswered, not alarmist, question: Say the tire delaminated a square of 12 inches or 18 inches. What is involved in testing and repair? Does hidden delamination spread beyond the visible? How big would the final repair area be compared to the visible area? What differentiates a trivial delamination from a more serious one?

lightningzap wrote:

aeromoe wrote:

lightningzap wrote:

Also I think Delta would much rather screw us over here at msp than those at detriot..

Serious question here just for my enlightenment: what would Delta have to do to have such an impact? Thanks

Moe

could be due to proximity of Detroit. They're downsizing a bit

I really miss the days of A.net being a paid site.

First it was the DTW people; now it's the MSP people claiming they're being "screwed." Please explain, how is Delta downsizing MSP?

You should realize that the two hubs have coexisted for decades and are 529 miles apart - nearly the same distance as ATL and DTW.

frmrCapCadet wrote:

The unanswered, not alarmist, question: Say the tire delaminated a square of 12 inches or 18 inches. What is involved in testing and repair? Does hidden delamination spread beyond the visible? How big would the final repair area be compared to the visible area? What differentiates a trivial delamination from a more serious one?

Delamination is "loss of resin matrix binding".

The design assumption of a "solid material" goes away.
Load cycling has a good chance of aggravating the damage.
Water ingress is another damage vector.