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Production of Boeing 787 Dreamliner Delayed Again
Hugh Pickens writes "Boeing has discovered microscopic wrinkles in the skin of the 787's fuselage and has ordered Italian supplier Alenia Aeronautica to halt production of fuselage sections at a factory in Italy. 'In two areas on the fuselage, the structure doesn't have the long-term strength that we want,' says Boeing spokeswoman Lori Gunter. To repair the wrinkles, additional layers of carbon composite material are being added to a 787 at the South Carolina factory and twenty-two other planes must also be patched. Production of the 787 has been fraught with problems with ill-fitting parts, casting doubt on Boeing's strategy of relying on overseas suppliers to build big sections of the aircraft before assembling them at its facilities near Seattle. The 787, built for fuel efficiency from lightweight carbon composite parts, is a priority for Boeing as it struggles with dwindling orders amid the global recession. Customers had been expecting the first of the new jets in the first quarter of 2010 — nearly two years earlier than they will be delivered. The delays have cost Boeing credibility and billions of dollars in anticipated expenses and penalties. Orders for 72 planes have been canceled already this year, although Boeing still has confirmed orders for over 800 aircraft."
Not all of the outsourcing is done to save pennies (although many of them undoubtedly are).
For example, many of the composite parts are produced in Japan for two reasons: 1) Japan has some of the best composite material manufacturers in the world, and 2) lucrative subcontracting business from Boeing distracts the Japanese from trying to produce a 787 competitor of their own. The latter is especially important, not just because the last thing Boeing needs is another credible competitor in the mid-to-large airliner market; it is also because a stronger Japanese aviation industry may also be tempted to design jet fighters on its own, which would destroy the single biggest export market for US military aircraft in the world.
I worked for Northrop many decades ago when the Boeing 747 was first being built. Northrop made these body sections for Boeing. These were in the days of actual blueprints on paper, although they had advanced to microfilm aperture cards to print from by that point ;)
The skins had little angled stringers attached to the inside surface, painted with some horrible green mixture. The draftsman who drew them used the wrong width pen, and these stringers turned out to be 1/2mm shorter than they needed to be. Not a real problem you'd think, but there were thousand of them running lengthwise across the skin.
By the time the stringer had reached the cargo door (65BO1859 - god how some things stick in your head) they were about half a meter short. This had a major structural impact on the airframe, so they had to go (literally) back to the drawing board to solve the problem.
Subtle business, building your average jumbo jetliner.
Do not mock my vision of impractical footwear
Since we're trading war stories...
Once I was hired at a sub to do the structural analysis on an empennage. The finite element model was supplied by the OEM and just by chance I did a sanity check by importing the catia geometry into patran and overlaid it on the mesh. Turns out the mesh for the whole horizontal stabilizer was 2" too high.
I have a good one from testing too. The same OEM had this jet going through cert testing and one of the tests is a particularly nasty scenario where an entire fuselage is pressurized then this big dagger thing punches a big slit in it about 40" long. The hope is that the big gash doesn't propagate and cause the fuselage to, you know, explode. This is supposed to simulate an engine explosion. Sadly the fuse went boom. That cost a bit to fix.
Speaking of things that are the wrong length, that happened to the A380 wiring. Things like that aren't supposed to happen with catia and all that. I heard that various people blamed it on different contractors using different versions of catia which doesn't make much sense. Probably just a basic mistake some designer made that never got caught.
Equine Mammals Are Considerably Smaller
No, you can bet that the competitors will win because repairing a graphite defect/delamination/crack/ requires a $100,000 hot bonder + materials as opposed to $0.10 worth of aluminum, $0.01 worth of rivets, and $80.00 worth of rivet gun.
Composites are really neat, and I love working on them, but mfg.+maint. of composite > mfg.+maint. of aluminum aircraft.
Just speaking from the air force side of things- going from Al to Carbon requires a manning increase in the structures shop of at least 3X. Graphite is a totally new game that most structures guys are simply not prepared to cope with. You need to take that into account when you're comparing budgets.
-b
No offense, but I've stopped responding to AC's.