Experiment is probably the incorrect term, they will have had many 'experiments' before going with the composites. It would be correct to call this a "demonstration of a major structural repair of composites." the prime objective will be to get it right.

From an industry point of view everyone will be interested - it is not a Boeing only problem, A-350's will be in the same boat. An effective repair and back to flight will quieten the noise from the peanut gallery about composites. Already, thanks to the prolonged flame throwing ELT strapped right against the composite hull, it is apparent that composites will not irretrievably combust.

This mishap although unwelcome could in the longer term become a positive.

Ian

Am not Boeing bashing but the A350 is manufactured using composite panels I would think a lot easier to repair than Boeings barrel construction.

Assuming that's what they are going to do this time ...

Reading the tea leaves
 

I interpret the Flickr picture as follows:
The VS is off the aircraft because it was in the way for some of the structural repair that will occur. The aft scaffolding defines the area that will be receiving significant structural repair along the crown of the fuselage.

Next, They will build a tent over the scaffolding that spans the aft fuselage.

Watch the forward scaffolding and the lower deck of the aft scaffolding for action. That will be the outflow of internal components as the strip out commences. Start your repair stop watch then. What you see now is facilitation.

The total operation is likely phased so that the expensive repair crew spends minimum time on site.

All you sidewalk superintendents pull up a seat.:}

I expect them to erect a tent over the whole thing so all the sidewalk superintendents will have to guess what's happening inside

Assuming of course the fire did not melt/burn the aluminium composite frame the panels attach to. How easy is that to replace?

In actual fact, the fire may have been propagated on the A350, as aluminium is a very good heat conductor. Who is to say the fire would not have taken out the whole crown and thus write the thing off?

But, like your suggestion the A350 would be easier to repair, that's idle speculation :ok:

Agreed.

Most of the grousing comes from those who are thinking of older types of composite, or those who are basing their reasoning on flawed, outdated or simply incorrect information. Admittedly when the concept was first floated I was thinking of the Comet days and that it would be a leap into the lesser-known material properties of a similar magnitude - but later reading somewhat calmed this opinion when it became clear that the level of modelling and physical testing as well as materials knowledge was much more thorough.

Biggest Airbus A350 XWB carbon fuselage panel manufactured | AVIATIONNEWS.EU

http://www.eads.com/dms/Press-DB/EAD...ag_490_318.jpg

http://www.aviationnews.eu/blog/wp-c...18-400x259.jpg

Very interesting indeed!

some more info: Sources: Damaged Ethiopian Airlines Boeing 787 to Undergo Major Repair in London » Airchive

"once the damaged areas are sanded away" - love it !!

Even better "The incident was sparked on July 12th......"

The workers are probably union and paid by the hour. :bored:

Unions
 

Ozlander:-

"The workers are probably union and paid by the hour"

If that was the case I would say good for them. Why would anyone do otherwise?

The tragedy is that in Britain today (and for the last 30 years) workers are getting poorer year by year and bosses (to make it simple) are getting commensurately richer.

The whole British economy is now run on a Pay To Fly basis.

If you do not think that you can get yourself into the top 10% (today about £160k) then I recommend that you leave Britain. The top 10% are presently in the process of rendering the rest of the population destitute.

Because they can.

£160k puts you well into the top 1% of UK tax payers, and this 1% contribute some 30% of tax revenue.

so yes, they are really ripping off the system :ugh:

That will be highly depending on the price tag that is attached to the repair.
Nobody said it would not be possible to repair composites. The remaining question is whether it is economic to do so.
And this event, linked to an incident and an investigation, is probably not representative for the time it requires to do such a repair.
So there will be more noise in the future

This has been settled long time ago.
Every repair is different but airlines are interested in repairs that happen most often - bends and nicks caused by service vehicles at airports. This is where they loose a lot of $$ every year. The repair techniques developed for such repairs in the composite world are multiple time faster than with the aluminium body and some small damages that require repairs on aluminium aircraft will require no repair at all on a 787.

olasek

As I'm sure your aware this "incident " hardly comes into said " bends and nicks" category.

So. Does anyone have some fresh pictures of what is going on?

Have they started stripping out the interior?

You don't have to see into the tent to make an educated guess as to what is going on inside. Just observe the flow of material in and out.

No, it doesn't but you clearly missed the thrust of my argument. I was talking about aircraft skin repair in general, those that produce largest losses for airlines. Also, there are many aluminium repairs that are no longer economical.

olasek

Care to elaborate, and by the way, how do you know this is correct?

Regardless of construction materials I see little similarity between a minor ding caused by a service vehicle and the damage caused by this fire. This has taken 3 months of planning and a fair build up of tents, equipment and materials.

The cost of all this, plus the cost of all the airport space, the repair team and the loss of revenue put this event into an entirely different category, one which will hurt the Insurers, Boeing, Honeywell and Ethiopean.

DavereidUK
 

Your surprise at the comments about " sanding the damaged part away" show your lack of understanding of composite repair techniques, to my surprise and delight it would seem that the composite engineers have won the day and we are not going to see a metalcentric repair if this report is true.

Full marks to Boeing for keeping faith in the composite technology.

Gosh, that's told me.

And to think that I turned down the chance to buy shares in that sandpaper manufacturer. :ugh:

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 ?

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.”

Goes on ...

Excellent post DWS :ok:

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!

There was a PDF article on the subject. They were talking about ADL (allowable damage limits) for both aluminium and carbon fibre fuselage aircraft in typical airport ground operations, carbon fibre is much stronger and will absorb significant hit by a ground vehicle before reaching the ADL while the same collision will necessitate pulling aluminium aircraft from service and repair. Such ground collisions are more frequent than people think, airlines lose a (~) billion $$ every year, anyway there was an exact figure and it was pretty staggering.

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 ..

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?

'Cirque du Seattle' latest - the fin (sorry, vertical stabiliser) is off !

- you mean they put it back on again? Posts #976/7:confused:

Sorree, hadn't seen those threads......been a long day !

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

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..

Which dates even further back than this repair design. Composite engineers have already won in the design phase and the fuselage is no longer built from riveted (black metal) panels but the wound fibre design of the pressurized fuselage really takes benefit of the superior properties of composites. However, in an anisotropic material strengthened in only one direction (where the hoop stress dominates the laoding) may simply no longer have the bearing strength to do a metalcentric riveted repair. A scarf joint bonded repair may be the only method to repair the wound fibre barrel. So now we get a "better" composite repair than in the past of transport aircraft (in fact we get exactly that type of repair which has alwys been done to wooden aircraft and has been done for composite gliders since the 60s) which may however take a little longer and cost a little more, but will ultimately give the much better results.
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...

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.:D

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

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.

2 months of tent time

Anyone volunteering for the test flight?