Michael Birbeck's comments
Read this guy's take on the respective A380 and 787 programmes. It is an uneven read and I certainly don't agree with all his stuff but it is interesting.
Lonely Scientist
I wish them the best. The 787 is brave step forward and I bet the programme will come to be seen to be ground breaking (not Boeing breaking) in years to come.
With respect to my comments Lonely Scientist PM'd me. I post his message to me (with his permission).
I don't endorse his thesis but am rereading it in the context of his book preparatory to responding to him personally.
@Lonely Scientist
I agree that it is still an uneven read - has yet to be edited - and of course I do not expect everyone to agree.
However I am not in total agreement with your further remarks on the 787 and I do not bet - actually I am convinced - that the 787 and the A350 and the (wings of) the A400M will prove to be failures, sooner than later. I challenge ANYBODY to come forward with one single argument that justifies the application of composites in aircraft: In the way they are applied here for externally exposed primary structures. On the other hand there are numerous reasons not to apply composites for these purposes - as have been detailed in my book. Plain composites do not save any weight and have very low damage tolerance - these materials are just not suitable and there is nothing that can be done about that.
My involvement with this is only to save lives - a late wake up call may be, although my first reports are from January 2008; that was, when the first delay with the 787 was just announced.
As you stated in your comment - ‘stress concentrations that were not compatible with their computer model’ - and this is at the root of problems. The computer simulation programs that are in place don’t work. Engineers at Boeing are completely in the dark – may be difficult to believe for you, but true. Mind also that aircraft are dynamically loaded in flight and static testing that has been performed so far provides only an approach. A 150% safety margin is applied, similar to aluminum aircraft, but based on what?
The first six 787 test aircraft - four to fly - are heavily overweight, some 20,000 to 25,000 lbs, and were already patched up. The problem that now surfaced are not the first one. The centre wing box - the foundation of the aircraft - failed at an earlier bending test, actually before the plane was rolled out the first time July 2007. It took some two years to design and test a new wing box but the old planes were left with provisionally strengthened wing boxes. History is repeating itself, when two years later just before second roll problems were detected with static testing with again the centre wing box involved and now also the connection of the wings to the centre wing box has to be provisionally strengthened - but how to do this without reliable models - and than static tests have to be repeated. In the meantime another most worrisome development were the thousands of wrongly placed fasteners that were discovered during the blow test September 2008. No provisional strengthening this time: Boeing decided to replace these fasteners after test flight - which is both stupid and irresponsible, to say at least, given the circumstances.
What is the point of testing a plane for certification that is heavily overweight and is held together by a provisionally strengthened wingbox, a provisionally strengthened connection of the wings to the centre wing box and thousands of wrongly placed fasteners - to mention only a few of the structural problems.
What you see here is a pattern of failures each time when the structure is loaded. And these are still the least of problems. The main concern with composites is their very low damage tolerance. On impact the windows perform far better than the composite skin. Composites provide no protection again lighting strike and you are not going to believe that a couple of hundred pounds of wire mesh inserted in the composite skin are going to provide a Faraday cage as is obtained by some 25,000 pounds of solid aluminum with traditional aircraft. With fire the resin adds fuel to the flames – at the same time the carbon fibres break up producing large amounts of respirable fibrels probably more dangerous that asbestos. To mention only a few of the problems.
As I tried to point out in my book, the future is not to all-composite but to composed aircraft where aluminum reinforced composites, that are already successfully applied with the A380, will play an important role next to plain composites that can be used for parts that are not externally exposed (centre wing box, keel beam and so on) together with monolithic aluminum (aluminum lithium has very poor impact performance) and of course titanium.