Ethiopean 787 fire at Heathrow
Your surprise at the comments about "sanding the damaged part away" show your lack of understanding of composite repair techniques.
And to think that I turned down the chance to buy shares in that sandpaper manufacturer.
But I suspect that whatever repair technique and materials are being used, cutting out the damaged structure doesn't just involve a bloke with a Black & Decker and a few sheets of abrasive, wouldn't you say ?
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Boeing to patch Ethiopian 787
Boeing readies patch for fire-damaged 787 | Business & Technology | The Seattle Times
Originally published October 21, 2013 at 8:56 PM | Page modified October 22, 2013 at 6:27 AM
Boeing readies patch for fire-damaged 787
Boeing will repair the 787 Dreamliner jet damaged in a fire at Heathrow by making a duplicate fuselage section and cutting out a piece of it to create a giant patch, in a process one expert says is “pushing the limits of what’s been done in the past.”
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Originally published October 21, 2013 at 8:56 PM | Page modified October 22, 2013 at 6:27 AM
Boeing readies patch for fire-damaged 787
Boeing will repair the 787 Dreamliner jet damaged in a fire at Heathrow by making a duplicate fuselage section and cutting out a piece of it to create a giant patch, in a process one expert says is “pushing the limits of what’s been done in the past.”
Goes on ...
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DaveReidUK
You are quite correct that it would involve a bit more than a bloke with a black & decker orbital sander but the discription although a bit rough and ready is a lot closer to the truth than a lot of the stuff written above.
The repair is not pushing the limits of what has been done in terms of technology............ It's just a bit bigger than other repairs and the whole world is watching and looking forward to Boeing getting it wrong............ My money is on the peanut gallery being disappointed!
The repair is not pushing the limits of what has been done in terms of technology............ It's just a bit bigger than other repairs and the whole world is watching and looking forward to Boeing getting it wrong............ My money is on the peanut gallery being disappointed!
Last edited by A and C; 22nd Oct 2013 at 15:02.
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Care to elaborate, and by the way, how do you know this is correct?
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A side note re composites - cutting repair
Cured composites as in the 787 can be lightly sanded- BUT for any serious work as in drilling or cutting, either carbide and or diamond abrasive tools are needed.
For example regular HSS drills wear very rapidly in just a few holes- although some specialized surface treatments reduce the wear factor.
One of the problems in the normal cutting and trimming of composites was the abrasive dust involved in trimming large panels at a reasonable rate wtih high speed cutters.
In the 1980's- I designed a brazed diamond cutter " grinder " which was used to cut major composite sections of the B2
Several years earlier- another BA employee designed a carbide drill for similar material looking like a sharp pointed fluted reamer.
I mention this cuz most seem to think that carbon composite is easily cut. yes pure carbon threads can be cut- But when combined with epoxy like material and cured, its a whole different story.
Yes one can take a normal HSS drill used on aluminum and steel and drill a hole or two or three - but then the diameter of the drill will be somewhat less than when started. In a production environment - this is unacceptable.
And yes - industrial diamonds can be brazed on steel tools ..
For example regular HSS drills wear very rapidly in just a few holes- although some specialized surface treatments reduce the wear factor.
One of the problems in the normal cutting and trimming of composites was the abrasive dust involved in trimming large panels at a reasonable rate wtih high speed cutters.
In the 1980's- I designed a brazed diamond cutter " grinder " which was used to cut major composite sections of the B2
Several years earlier- another BA employee designed a carbide drill for similar material looking like a sharp pointed fluted reamer.
I mention this cuz most seem to think that carbon composite is easily cut. yes pure carbon threads can be cut- But when combined with epoxy like material and cured, its a whole different story.
Yes one can take a normal HSS drill used on aluminum and steel and drill a hole or two or three - but then the diameter of the drill will be somewhat less than when started. In a production environment - this is unacceptable.
And yes - industrial diamonds can be brazed on steel tools ..
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Thanks for that interesting post DWS.
I worked a fair bit with fibre-glass in the past and found sanding to be very unpleasant and there are now various health concerns about it too!
I would be very interested to know what Health and Safety precautions the repair team in this job (complete with their "sanding discs!") will have to take...will it cause the itching that Fibre-Glass does, is the dust hazardous, that sort of thing?
I worked a fair bit with fibre-glass in the past and found sanding to be very unpleasant and there are now various health concerns about it too!
I would be very interested to know what Health and Safety precautions the repair team in this job (complete with their "sanding discs!") will have to take...will it cause the itching that Fibre-Glass does, is the dust hazardous, that sort of thing?
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DWS: Aren't most of the holes in composite panels done by orbital drilling nowadays? Drilling CFRP panels with ordinary drills usually leaves irregular holes with chaffed edges.
Edit: at least it seems that 787 panels are drilled this way: Boeing Places Subsequent Order for Orbital Drilling Equipment for 787 Dreamliner Final Assembly
Edit: at least it seems that 787 panels are drilled this way: Boeing Places Subsequent Order for Orbital Drilling Equipment for 787 Dreamliner Final Assembly
Last edited by Grunff; 22nd Oct 2013 at 21:14.
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re composite cutting
My comments were intended to be specific to field repair. Orbital drilling if you note is a factory- machine tool- sub assembly drilling of large holes prior to or during final assembly and not likely to be used in the field.
In then field, hand drilling and reaming are the most common methods used, or in some cases, a bolted on drilling/assembly - alignment jig may be used.
I'm sure Boeing plans to learn a lot about relatively large scale composite repair in this case.
Side note for a long time, people were worried about composite ' dust' being able to short circut electrial- electronics - base on conductivity of carbon.
so a ' cigar box ' sized clear plastic box was made, and filled with composite grindings, slivers, etc. probes were placed in the box ( like your standard ohm-meter ) and as I rcall, the box was shaken rattled, turned, etc and measurements were made of any conductivity. Answer of course was zip- nada- nothing.
What most did not realize was that for conductivity to take place with coated carbon fibers - a few hundred pieces of ' dust'- slivers would have to line upm end to end and make contact with the carbon fiber. Sort of like gettting a bunch of hot-dogs to line up end to end while surrounded by a bun.
That being said- the dust is still something to be avoided in electronics..
In then field, hand drilling and reaming are the most common methods used, or in some cases, a bolted on drilling/assembly - alignment jig may be used.
I'm sure Boeing plans to learn a lot about relatively large scale composite repair in this case.
Side note for a long time, people were worried about composite ' dust' being able to short circut electrial- electronics - base on conductivity of carbon.
so a ' cigar box ' sized clear plastic box was made, and filled with composite grindings, slivers, etc. probes were placed in the box ( like your standard ohm-meter ) and as I rcall, the box was shaken rattled, turned, etc and measurements were made of any conductivity. Answer of course was zip- nada- nothing.
What most did not realize was that for conductivity to take place with coated carbon fibers - a few hundred pieces of ' dust'- slivers would have to line upm end to end and make contact with the carbon fiber. Sort of like gettting a bunch of hot-dogs to line up end to end while surrounded by a bun.
That being said- the dust is still something to be avoided in electronics..
Last edited by DWS; 22nd Oct 2013 at 23:23.
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the composite engineers have won the day and we are not going to see a metalcentric repair
To be exact the prefabrication of "spare parts" in the original production mold and splicing that into the damaged airframe by a bonded repair is more the style of wooden aircraft repair, than that of composite gliders where you often build the "spare part" in situ with a special tooling mold, so that producing and bonding is a single step.
Finally we do not only get transport aircraft made from composites, but we really get composite aircraft...
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Volume
You are the first person on this thread who has demonstrated a practical understanding of the composite repair subject.
Some above have a grasp of the theory, but not the practice.
Some above have a grasp of the theory, but not the practice.
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The latest photo shows the tent erected over the rear fuselage and the VS standing upright not too far away:
Boeing 787-860 Dreamliner (ET-AOP) Aircraft Pictures & Photos - AirTeamImages.com
Boeing 787-860 Dreamliner (ET-AOP) Aircraft Pictures & Photos - AirTeamImages.com
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Thanks for the picture Andy.
I looks like as pointed out up post that providing environment for the repairs of the CRFP may be of extreme importance.
The down side is we will not get to see much of what goes on.
I looks like as pointed out up post that providing environment for the repairs of the CRFP may be of extreme importance.
The down side is we will not get to see much of what goes on.
Permanent or temporary fix
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Anyone volunteering for the test flight?
I did already aerobatics on a composite glider where the wing was in 3 pieces before we repaired it. A scarf joint repair of unidirectional carbon fibre spar caps works fine. Why should a wound fibre fuselage be different ?
the VS standing upright not too far away
