Thank you for your comment. Of course my statements must be questioened, that’s why I took the unusual step to publish the draft text on the web for comment.

More specific to your comments. I am not sure whether it is important at all whether you believe or not believe AA certification. As I state in my book ‘Certification – although recognized to be of utmost importance – is in this respect a relative idea since every commercial aircraft that crashed in the past was certified and flaws in design and unknowns including wrong choice of construction materials or different then expected material behaviour were often found afterwards to be the cause of accidents including a number of fatal accidents – some described in detail in appendices of this book’. It is also not relevant that four different nations are involved and that applies also for the application of composites with an aircraft that is just in the air.

My request is therefore to more specific. For example how do you know that the 150% safety margin applied with testing of aluminium aircraft does also apply with all composite structures – engineers that designed the Comet deemed 200% enough, four planes crashed and hundreds died because of ignorance. What do we know about crashworthiness of the 787 other than some verbal ‘assurances’ from Boeing and that applies also – even more so – to lightning strike protection. Do you really belive that a couple of hundred of pounds of copper wire mesh in the composite provides a Faraday cage – prove it. And what about electromagnetic shielding with hardly any metal left. My book discusses many of such issues and again – come with specifics.

Having said that I believe that the A380 is a great plane that paves the way for composed aircraft. However, safety has to be awaited. Personally I don’t feel comfortable with the wing test that broke some 3% short. The rules of the game – as I understand them – are that when you strengthen the part, the test has to be repeated. Be very careful with CATIA when composites are involved.

I would very much appreciate to receive more specific comments – hope that you do.

Regards,

Hans

Airbus started from scratch (albeit with significant experience in the founding UK, French and German companies) and so had a freshness to its design that Boeing didn’t have. Now both companies have significant expertise in metallic aircraft design, but they are at a ‘rule change’ that makes the F1 rule change pale into insignificance. This rule change from metallic to composite primary structure in the aerospace industry calls for brilliant engineering solutions, not iterations of a structural design philosophy that has hardly changed since the Boeing 707. It seems to me that both Boeing and Airbus are producing ‘black metal’ versions of metallic aircraft, because they have spent so long iterating the metallic designs that they have forgotten the first principles, and evolved their current design rather than taking a fresh look at things. Certainly if you were to look at a digital mock up of an A350 wingbox and an A330 wingbox you would be hard pressed to see any significant differences. So, money is being poured down the drain because both the industrial behemoths are relying on their previous experience to build a metallic aircraft made out of composites, rather than recruiting Burt Rutan style engineering brilliance to design a truly composite aircraft. Like the big F1 teams they will get there eventually, but they probably won’t get produce a truly successful composite aircraft until the next generation of single aisle aircraft, which from what I have seen appear much more innovative. That is if they don’t have their fingers burnt too badly on their 787/A350 programs….

Finally, you mention the engineering expertise in Germany and France behind Airbus’ intiial success. You should note that the wings are designed and built in the UK and are extremely aerodynamically efficient and weight efficient compared to the Boeing wings. The wings are the most technically challenging structure on the aircraft, and therefore I would argue that, in terms of the structure, the UK has produced the most innovative and successful structural items for Airbus.

I’ll get on and read the rest now. Having worked on Airbus A400M and now A350 since 2002 it initially looks like you are talking a lot of sense, but I’ll reserve final judgment until I have finished!

No comment or so, but only some language problems. Do with them what you like.

chapter 3
Other special conditions
Recent research by the FAA shows that aluminium fuel tanks behave indeed very differently from aluminium fuel tanks 245).
I think first word aluminium has to be composite:

What’s left is improved flying experience
is applied – horizontal gust horizontal gust suppression is already applied with the 777 and the 787 is also
I think horizontal gust is double

Take Care
Moreover, the 787 is a fist ‘more electrical plane’ and that might play havoc
fist???

With kind regards,

I have been a structural engineer for over 30 years and have been exposed to many different types of composite structures.

Stated simply, I cannot understand the almost religious obsession with the aircraft industry and composite materials. I have witnessed numerous failed structures as well as programs due to this obsession.

I will not bore you with details now. I just wanted to touch base with you since I just learned of your website Lonely Scientist. I am looking forward to studying you work and would like to follow you in your journey.

I too would someday like to write a book on this topic… who knows, maybe I will.

Should you ever send out information to followers via email, please include me on your list.

Sincerely,

Martin

All this can be resolved, but it requires very much time and it
signifies a steep learning curve on the development as well as
on the production side.

The impending failure of Boeing’s Dreamliner has the following reasons: Boeing wanted to catch up with Airbus in one single giant leap forward. But Boeing underestimated the difficulties involved. Boeing had nearly no foreknowledge about distributed production, about composites, composite-metall constructions and their bonds and also about self diagnosing
engines.
This is, why Airbus will succeed with the A350 XWB. Because
Airbus already has all the foreknowledge required. Airbus
already uses all the logistics and technologies involved to a
lesser degree in its existing products, especially in the A380.
Airbus has a solid fundament of knowledge and experience in
these fields, on top of which it can build up.
There is much more time available for the difficult finesses,
for ingenuity based on time consuming experiments.
To get the required results during development of a new
product, a certain serenity and sobriety is needed.
All this is not possible, if you must start everything from
scratch, if you are in a constant hurry, always teetering
on the brink of overchallenge.

A review of your book has been posted on Plane Talking.

http://blogs.crikey.com.au/planetalking/2009/06/28/dreamliner-an-impossible-dream/

I think it has made an important contribution to public discussion about future issues that may arise with high composite airliners.

However I think you should disclose any involvement with any of the interested parties in this issue, should this be the case, in the interests of full transparency.

We need to know more about you.

I recently ran across your prerelease on composite aircraft and believe you have gone out there a bit to the extreme. Composites can be superior, it just takes far more finesse, competence, and design skill to make them work. And hence the biggest reason for the failure of composite designs to be competitive is the lack of talent doing the designs. In case you are not aware, most of the aircraft industry has gone to an integrated project team type organization where engineers are just a widget in a plug and play system, with any one of them being basically considered of the same caliber as the next. Likewise with subcontractor input and parts. What this leads to is management having no clue as to how good the performance is and where or who has any expertise to excel and get the best results. The answer of one engineer is just as good as another. One subcontractor is just as good as the next. Under this type of organization the design gets mired in mediocre output just when the use of composites demands excellence.

I am a very experience structure analyst that has worked on many composite aircraft, everything from the B2 to the most recent being the Global Hawk. The use of all composites for the Global Hawk wing for instance gives results that one could never achieve with metals. It uses high modulus fibers that provide the stiffness the wing needs to make the wing very long in span to maximize its lift potential at a much lower weight than can be achieved with metals. And most of the wing is just glued together to minimize the costs of its assembly. This is just one example of many.

My point is that from what I have read, you are making statements in your book that are a little too pointed or extreme and you may want to consider toning them down or better define them instead of generalizing to the degree you seem to be doing. The key to success with composites as with all things is judicious use of them by skilled engineers — not widgets doing the work.

Admittedly, I have not read all of your book, but will if I get time. From what I have skimmed however, this is my response.

Good Luck, I know how much work doing something like this is.

…Bryan

Here is what I wrote on the 787 in July 2006:
http://www.boeing787skeptic.blogspot.com/

And 5 or 6 years before that, Aluminum vs. Composites:
http://www.aerotalk.com/index.cfm?action=view&ForumID=8

Keep up the good work.

Stan