It may have nothing to do with safety of flight - but it has everything to do with public perception, not to mention Boeing's stock price.

To acknowledge that at this early stage in the 787's career the first one has been written off would be a PR disaster (though arguably Boeing are getting used to those).

On the other hand, the thermal conduvtivity of molten aluminum is still about the same as for solid one, while the thermal conductivity of charred CFRP is far less, than the one of intact one. Therefore thick CFRP will protect itself from a localized heat source, while Aluminium will burn through locally. However, this means structural damage and requires a repair. It also means toxic fumes. But especially for thicker material, CFRP stands a local fire better than aluminum from a load carrying standpoint. For thin material both will fail anyway. A hot spot like a shorted wire or an arcing one may do more and more localized damage to CFRP than to aluminum, due to the localized heat which is better dissipated for metals. But when charred on the surface, this effect will quickly compensate the localized heating.
Also remember that for items mainly loaded in plane tension (e.g. a fuselage skin), burning of the resin does not keep the carbon fibres (good for > 2000 °C) from carrying tension loads. Molten Aluminum does not carry anything.
You simply can not compare apples and oranges. And I do not say CFRP is better!

It could just be, given that it seems the Honeywell ELT was a key player in all this, that there are some 'full and frank' discussions going on behind the scenes as to exactly who's insurance company is going to be paying anyway?

Boeing stock is trading within a percent or so of it's all time high (and that all time high occurred after the Ethiopian 787 fire) . I'm guessing the public perception can't be all that bad.

tdracer, you don't understand. The sky is falling, or at least for those that wish to remain clueless about this business. ;)

Lots of aluminum airplanes have been lost or badly damaged due to fires. I'd guess almost all of those fires started small, then found fuel somewhere besides the aircraft skin.

Perhaps there will be a whole new class of fires caused by heat sources in proximity only to composite skins. I personally doubt that will happen, but time will tell.

FAA studied fire hazard of composite skin
 

Sorry I can't find the reference again - I mentioned it a couple of times in the original battery thread - but the FAA commissioned a study at a university on composite material that iirc was specifically that which was intended for the B787. I have no expertise in the area but glanced through the report and at least did not see anything obviously bogus about the tests or conclusions (that the skin would survive fire well.) Of course, they thought the Li-Ion battery system was perfectly safe, too, so some of the points mentioned up-thread here might have been overlooked.

If anyone is interested in the report and can't find it, ask and I'll dig out a link to it.

If you have the link handy, I'd certainly appreciate it, thanks.

There is one here http://www.fire.tc.faa.gov/pdf/07-57.pdf

From Boeing's 787 Aircraft Rescue & Firefighting Composite Structure


http://i337.photobucket.com/albums/n...ps86f4de32.jpg


http://i337.photobucket.com/albums/n...psb4c3e184.jpg

Machaca
Boeing total PR codswallop And if not a problem, why epoxies banned for interiors since 1970's?

Why are you conflating interior fitment and structural epoxies?

Seems disingenuous, particularly when you don't address the specific burn properties of the modern epoxy developed for the 787.

Please enlighten us all by addressing the seven bullet points above.

My read between the lines of the Boeing PR is the major source of toxicity is the interior panels of the aircraft.

Neither the aluminum nor the 787 outer structure contribute significantly except for the time to be defeated by an external fire.

My memory of such external fires is almost solely comprised of ground fuel-pooled fires.

An internal cabin fire is clearly another problem.

I am curious what a Asiana fuselage might look like along the fuselage top after the fire breaks through to inside the cabin, but that's just a structural damage question and not germain to toxicity.

lomapaseo

My concern is that the vast majority of survivable crashes, (in fact the norm) for commercial aircraft result in compromised, fractured, open doors , open slides,etc, thus allowing ingress into the cabin of toxix gases and smoke from the external CFRP fire. I have cited over 150 such commercial airline survivable crashes to both Boeing and FAA since 1970, all involving compromised and fractured fuselages to no avail.
To my knowledge this critical safety condition was never tested for during development and certification of the 787. Specifically, Boeing did burn-through tests via cone calorimeters only on intact and non-compromised panels and the FAA and Boeing both refused to replicate the Air France A340 Malton overrun crash a few years back, which would serve as an ideal and totally reproducible example of such survivable fuel fed fire crashes. This could easily be performed on on of the four now non-flying 787 prototypes and such a test, replicating a survivable fuel fed fire crash with 100% passenger and crew survival in the case in the A340 with a fuel fed ground fire would end the debate on either side of the FST issue.

To quote the old aviation aphorism "One test is worth 1000 expert opinions".

Then I guess, amicus, passengers flying on the CFRP A350 and the significantly CFRP and composite (GLARE) A380 are also pretty much whistling past the graveyard every time they board one of those planes, as well.

In fact, having flown the 787 and A380 a number of times (and with my airlines of choice also choosing the A350), I guess I better make sure my life insurance is up to date. :mad:

And god save us when the CFRP A320 and B737 replacements start entering service in the 2030s... Ralph Nader is no doubt working on a new book to lambast Airbus and Boeing on their decision to move to CFRP. I suggest he go with the title Unsafe At Any Altitude. :D

amicus:
Refused who? Why reproduce an accident from which everyone successfully evacuated?

I assume refused HIM. HE suggested and they refused, how nasty and inconsiderate of them.
Assuming there is a debate. This forum is hardly a place to find out if there is a debate (among real 'experts') or not.

Well if Boeing should destroy one of the 787s in such a test, Airbus should also be required to sacrifice MSN001 of the A380 and A350, as well. :rolleyes:

Now that the -9 is flying and gaining orders, what odds on Boeing slipping out the bad news regarding the Ethiopian 787 being "beyond economical repair".

Wouldnt put the A380 'Glare' in the same league as carbon fibre . Anyone remember the hazards with the harrier composite materials in an accident . Boeing wouldnt be aware of that having responsibility for the AV8B now......!