Tuesday, September 18, 2007

Barrels for the A350? Maybe, Maybe Not.

Aero-News informs us that the A350 PotemkinLiner has undergone another stunning iteration of the paper aircraft-the fuselage will now be constructed of CFRP barrel sections.

If this story holds up, it represents a stunning turnabout from all that has gone before.

Last week we were informed by the Wall Street Journal that the fuselage frames of the PotemkinLiner were to be made of CFRP and the Airbus cheerleading section lead by the Dutchman were falling all over themselves with this demonstration that yet again Da Festung got it right while the competition was hopelessly stuck in the past, might as well pack it in, panels are better than monolithic construction, change em out in a jiffy without even deplaning the passengers, we always said titanium was bad stuff, all frames are not created equal, and so on and so forth.

I guess that this is about the 10th iteration of the A350. It is not profitable to restate the obvious. The original idea was a quick and dirty, low cost upgrade of the A330, capture some sales that might otherwise go to Boeing's 787 then in development, and according to John Leahy, why they'd just write the operators a check for the fuel mileage penalty. Wrong.

The market was unimpressed, and Airbus, mired in the toils of the A380 debacle and not yet coming clean about it, reluctantly decided that Al-Li skin would get the j-o-b done while avoiding the unknown problems of composites, which of course the hated yanqui backwoodsmen were threatening the safety of the flying public with. Wrong again.

The market spoke again and it said "Wrong again." Meanwhile the trade was voting with its dollars and its orders.

Then we had the A380 meltdown go prime time. Airbus reinvented the A350 CFRP concept, only this was going to be panels on aluminum frames-black aluminum if you will, and if you recall we have stated on frequent occasions that this approach could not maximize the benefits of CFRP monolithic construction.

The advantage is one of integrity. What monolithic structure gets you is strength of the structure as a whole, and your formers and frames need only be stout enough to support the in cabin necessities for carrying folks around-ductwork, seats, flooring and the like. The barrel is the primary structure.

Think I'm wrong? Go to Office Despot and get a cardboard tube of the type used for rolling up and shipping girlie calendars. Try and bend it.

Now, after you've done that take the same tube, and cut a bunch of panels out of it. Tape them back together right where they came from with cardboard formers to back them up. Then go aheand and bend that sucker. But I'm getting away from my story.

Well, nevermind. The panel approach would be much more maintenance friendly, unzip the velcro, change a panel in a jiffy and Bob's your uncle-ignoring the fact that the kind of damage that would necessitate such a repair is so infrequent as to be statistically insignificant. Nevertheless it was a talking point that a lot of true believers bought.

Now we've come full circle. The A380 is still the answer to a question people stopped asking years ago, maybe one will get delivered in a few months or so, and if Aero News proves accurate on the point, the latest iteration of the PotemkinLiner has probably been set back a couple more years as Airbus tries to figure out how to build CFRP barrels while contracting around Boeing's intellectual property in the field.

Maybe they'll buy a license.


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