Boeing 787 dreamliner : troubles

Post by **ElcoB** » 18 Jun 2006, 21:18

BusinessWeek has learned that Boeing's engineers are wrestling with several significant technical and production problems that could threaten the scheduled 2008 delivery of the jetliner.

Full Article.

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bits44 · Post by **bits44** » 18 Jun 2006, 22:50

Old news! problems already been solved, it was an experimental mandrel, since been replaced with original metal one.

KT

smacDC-10 · Post by **smacDC-10** » 18 Jun 2006, 23:03

Very negative, it's too early in the program to judge. Has anybody here ever studied the Apollo program during the 1960's? It had nothing but problems but it worked. It looks like an attempt to make Airbus look better.

tolipanebas · Post by **tolipanebas** » 19 Jun 2006, 00:32

What I'd like to see answered is why Boeing wants to experiment with a new lighter mandrel during the production proces of a 'revolutionalory new plane' in the first plance, when the 'more conventional method' of production they have now returned to has not even proven itself in operation nor is certified by FAA?

Is the more conventional method not good enough to make the required fuselage sections withing time, weight and cost requirements for the 787 to deliver as promissed?

Stepha380 · Post by **Stepha380** » 19 Jun 2006, 01:40

I think (It's only my point of view and I don't have any proof of what I say) that Boeing has been too ambitious with the 787, I mean too much lightweight materials at one time, and the delivery program is unbelievable.
I just hope that time will prove me I thought wrong.

nwa757 · Post by **nwa757** » 19 Jun 2006, 05:05

Stepha380 wrote:I think (It's only my point of view and I don't have any proof of what I say) that Boeing has been too ambitious with the 787, I mean too much lightweight materials at one time, and the delivery program is unbelievable.
I just hope that time will prove me I thought wrong.

Why is it unbelieveable? Boeing already has much experience with composites in military aircraft.

Sure, the 787 will have some problems in the beginning, but every new aircraft does. The DC-10 had major problems in the beginning, but went on to be one of the most successful aircraft programs in history.

Advisor · Post by **Advisor** » 19 Jun 2006, 10:11

Anybody has a list of what all light weight materials are being used in the 787

teddybAIR · Post by **teddybAIR** » 19 Jun 2006, 11:52

nwa757 wrote:The DC-10 had major problems in the beginning, but went on to be one of the most successful aircraft programs in history.

That's a bit of an overstatement don't you think?

Stepha380 · Post by **Stepha380** » 19 Jun 2006, 13:13

Why is it unbelieveable? Boeing already has much experience with composites in military aircraft.

Unbelievable is the delivery schedule:
112 planes delivered in the first 18 months.
Boeing has asked its suppliers if they could increase their production in order to deliver 192 planes in addition of the 304 already scheduled between 2008 and 2011. That means 16 planes assembled per month on two assembly lines.
The decision concerning the second assembly line will be taken within the end of the month; the biggest challenge faced by Boeing is their own success: the delivery schedule is filled until 2011 in a single assembly line configuration.

Concerning the use of composites, maybe they should have begun with the wings on the 787 and the complete plane on the 737 replacement plane. Once again that'a only my point of view, maybe I'm not ambitious enough.

Wait and see.

(I'm a new member of the forum, and I really appreciate the wisdom of the fellow members)

nwa757 · Post by **nwa757** » 19 Jun 2006, 14:31

teddybAIR wrote:
nwa757 wrote:The DC-10 had major problems in the beginning, but went on to be one of the most successful aircraft programs in history.
That's a bit of an overstatement don't you think?

Which part? The DC-10 had problems with the cargo doors in the beginning

From Wikipedia:

This problem was first identified in 1972, when American Airlines Flight 96 lost its aft cargo door after takeoff from Detroit, but fortunately the crew were able to perform an emergency landing with no further incident. Before Flight 96 took off, an airport employee had violently forced the door shut, weakening the locking pin and causing the door to subsequently blow-out as the plane reached altitude.

446 DC-10s were built. Today the DC-10 is a very reliable aircraft.

From Wikipedia:

Despite its troubled beginnings, the DC-10 ultimately proved — and continues to be — a reliable aircraft, much loved by engineers and pilots. The original DC-10-10's notorious safety record continually improved as design flaws were ironed out and fleet hours increased. In fact, the DC-10's lifetime safety record as of 2003 is comparable to similar second generation passenger jets. [2] Increased inspections and modifications have made the DC-10 one of the safest aircraft to travel on.

Advisor · Post by **Advisor** » 19 Jun 2006, 15:11

Today a leading daily in India reports that the 787 will be able to take care of passenger comfort in many ways....and even make the inside air pressure as 6000feet above sea level as compared to the normal 8000 feet.

earthman · Post by **earthman** » 19 Jun 2006, 15:27

Too bad the teething problems of the DC-10 cost the lives of over 1000 people.

Stepha380 · Post by **Stepha380** » 19 Jun 2006, 15:39

the inside air pressure as 6000feet above sea level as compared to the normal 8000 feet

Are you forgetting the pressure resulting from the 9-seats rows ???

Did anybody already become sick due to pressure or humidity problem ???

I'm always so excited when I "fly" that I've never paid attention to it.

JoeCanuck · Post by **JoeCanuck** » 19 Jun 2006, 15:44

tolipanebas wrote:What I'd like to see answered is why Boeing wants to experiment with a new lighter mandrel during the production proces of a 'revolutionalory new plane' in the first plance, when the 'more conventional method' of production they have now returned to has not even proven itself in operation nor is certified by FAA?

Is the more conventional method not good enough to make the required fuselage sections withing time, weight and cost requirements for the 787 to deliver as promissed?

From what I understand, they were working on the experimental mandrel in order to increase production and reduce costs. It's not like the old mandrels were bad, they were just looking for something better and more efficient.

I imagine they'll keep trying to improve the production process.....and they should. Not every experiment is going to work....but if you don't try, you'll never know.

misako · Post by **misako** » 20 Jun 2006, 23:34

It is a known fact that CF/epoxy structures are particularly poor performers regarding FST (Fire, Smoke and Toxicity). That is why glass/epoxy interiors were all replaced with glass/phenolics under NASA direction and efforts back in 1970's, in which I participated.
The B-787 all CF/epoxy fuselage and wings pose major potential safety issues in this area, a matter I have not seen addressed in this forum. A similar problem exists on A-380 with CF/epoxy wing box and usage of GLARE (aluminum/glass epoxy sandwich) in the fuselage. A recent report from RMIT University in Australia confirms this significant issue and it will be interesting to monitor the actions of cerificating agencies in this area. I am hoping that suitable FST tests are performed prior to final certification to adequately address this potentially severe safety issue.

bits44 · Post by **bits44** » 21 Jun 2006, 06:03

An interesting read, for those concerned:

http://www.fire.tc.faa.gov/pdf/TN05-44.pdf

achace · Post by **achace** » 21 Jun 2006, 08:44

I think Misako makes very sound criticism, and thankfully not at all partisan.

The main problem I perceive is not that Boeing or Airbus will produce anything below specifications.

The issue is monitoring ground damage.

No groundworker will want to risk his/her job by reporting inflicted damage, and one of the issues raised with the faulty fuselage section was the "wallpaper" bubbles, and the risk of water ingress.

Perhaps Misako is able to comment on surface damage problems not readily spotted if not reported relative to water contamination of the under surface.

Cheers
Achace

misako · Post by **misako** » 21 Jun 2006, 22:05

Thank you for posting the FAA report TN05-44, Bits44, and for those interested in this vital safety issue, as also mentioned by achace (thank you for saying I am unbiased, as I hope that I am), I would cite a couple of salient sentences from the Introduction section of the report kindly posted by Bits44.
These are: "HRR (Heat Release Rate) requirements for exterior composite structures did not exist at time of this writing" The report was published in November 2005!!!
And also "Currently no fire resistance requirements exist for exterior polymer structures on aircraft. However manufactures will be required to demonstrate that polymer structural composites provide equivalent safety to current aluminum structures". Given the low ignition temperatures, high FSTs and high HRR's involved, I believe that this is highly difficult if not impossible to prove. I worry, however, that both manufacturers are trying to slide by stating "equivalent to aluminum" rather than the extensive, witnessed and certified detailed fire testing which is clearly required. Safety demands that large scale tests be conducted prior to certification, in my opinion. The certification agencies should demand this, the travelling public and crews deserve no less.
Sorry, achace, I will answer your other question for B-787 mandrel issue later.

earthman · Post by **earthman** » 22 Jun 2006, 11:18

I'm sure Boeing and Airbus will lobby/bribe their new planes through any such certifications. Then the problems will only be addressed after many people die in fires.

Avro · Post by **Avro** » 22 Jun 2006, 11:38

misako wrote:The B-787 all CF/epoxy fuselage and wings pose major potential safety issues in this area, a matter I have not seen addressed in this forum. A similar problem exists on A-380 with CF/epoxy wing box and usage of GLARE (aluminum/glass epoxy sandwich) in the fuselage. A recent report from RMIT University in Australia confirms this significant issue and it will be interesting to monitor the actions of cerificating agencies in this area.

First of all welcome to this forum Misako.

I don't know the exact constituents of the 787 composites but concerning Glare I have to disagree with you. Glare performs much better than Aluminium regarding Fire resistance. Test have been made already !!

Glare is a material consisting of two materials with different burn-through characteristics. The aluminium layers show a behaviour identical to that of a monolithic aluminium sheet when exposed to fire. Aluminium of 1 to 2 mm thickness will burn through within a minute in post-crash fire conditions. The latter parameter is determined by the amount of soot eposited on the specimen.
In Glare, the aluminium layers are very thin and will burn through very quicklywhen exposed to fire. Within only seconds the aluminium layer with a maximum thickness of 0.5 mm burns through.

However now comes the great partof Glare:
After burn-through of the outer aluminium layer, the glass-fibre prepreg layer is now exposed to flames of around 1100 °C. The fibres in Glare are S2-glass fibres in an epoxy matrix. Since the melting temperature of the glass fibresare higher than the flame temperature, the glass fibres are able to keep the fire from passing the layer and thus create some sort of fire barrier.
The epoxy matrix however cannot withstand this heat and will carbonise throughout the whole thickness under those conditions. The carbonisation will cause complete delamination of the laminate, starting from the location of exposure. The delamination implies separation of the layers. This separation allows air to flow in between the layers, which consequently acts as an insulator.

The remaining aluminium layers in the laminate will then be protected by the insulating air barriers between the delaminated sheets and by the carbonised epoxy in the fibre layers and will remain intact.

Those excellent burn-through properties of Glare were already showed in many testss.

In 1994 fireproof tests were done by Boeing according to FAA standards on Glare 3 and Glare 4. The tests were performed according to Advisory Circular 20-135.

The results of these tests showed that Glare can be qualified as fireproof and can consequently be used for firewall applications.

I don't know why but many people are afraid of Fibre metal laminates even if they are far superior to the convential monolithic Aluminium in many areas. If they are designed well there should be no problems.

Chris

Aviation24.be

Boeing 787 dreamliner : troubles

Boeing 787 dreamliner : troubles

RMIT Report re CF FST hazard

Re: RMIT Report re CF FST hazard