Posted on 06/23/2009 8:46:35 AM PDT by AngelesCrestHighway
Before the markets opened Tuesday morning, Boeing issued a shock announcement that the first flight of the 787 Dreamliner has been postponed again. The company cited a structural defect prompting "a need to reinforce an area within the side-of-body section of the aircraft." Though Boeing chief executive Scott Carson is quoted in the statement saying that "structural modifications like these are not uncommon in the development of new airplanes," the issue appears serious. Adding to the impact of the delay is uncertainty: Boeing said it will be "several weeks" before it will even come up with a new schedule.
(Excerpt) Read more at seattletimes.nwsource.com ...
“but i belive we will see numerous incidents caused by fatigue of composite material when the planes get older.”
We already know the lifespan of composite materials based on the fact there are pressure vessels that use them and have for several decades. So far, no issues. Those pressure vessels hold far greater pressures and cycle more than an airliner.
The pressure at 6,000 feet is a mere average of 8psi difference from the outside pressure. That may fatigue metals like aluminum but composite materials suffer no lifetime degradation.
As we speak there are continual tests being performed on composite materials to ensure they can withstand far greater stresses and cycles than an airliner could ever hope to achieve. They strike them with various metals and forces to ensure accidents can’t cause premature failure. They subject them with high voltage and soak them in acid water with many times greater strength than acid rain could ever produce, including that from volcanoes. They purposefully build them improperly to ensure even poorly constructed layers of strands do not cause failure. By far and large, composite materials perform better and are more reliable than their aluminum and steel counterparts.
Toss in the real-world use of these materials from lightweight general aviation aircraft to high performance military aircraft to even space vehicles and warhead shrouds, and we know how they perform. Failure is not expected.
“to do what my generation did in 9 years, go to the moon”
Nothing like admitting you are old and frail and have failed to advance your knowledge. Thank God your generation didn’t follow your lead and stick with stone tablets and loin cloths.
Oh, and for the record, it IS the 60’s generation using these composite materials. They knew about them then and have worked for decades to perfect them for our use now. They did a good job.
“But we have many decades of experience on long-term aluminium usage, something we don’t have with carbon fibre.”
As I pointed out in the other post, these are not new materials. They are in common use.
They have been used in submarines, airplanes, pressurized water tanks, acid tanks, tools, space vehicles, etc. Even my 8 pound sledge hammer has a carbon fiber handle. It worked great breaking up concrete. I even use it in high temp applications on my race bikes. Again, this stuff has been around along time now and has earned its place in engineering. I have literally trusted my life to it.
Yep, and the smart ones knew where and what to use it for, non-critical items like race car chassis, ailerons, rudders, cover hatches, etc. Not stuff that will kill 400, maybe 800 people.
Boeing and the rest of the aircraft industry have invested billions and billions of dollars on composites. They will spend whatever it takes and blame anybody else but themselves to save themselves when these composites start taking lives. Oh, I forgot, they already have, Airbus blamed that pilot for using the rudder, tearing off the composite vertical stabilizer and killing all onboard.
And now, Airbus is trying to blame pitot tubes with no evidence.
Composites are nice in a perfect world.
” tearing off the composite vertical stabilizer “
Did the composite fail or did the connecting structure fail? Bad engineering versus bad materials.
Update in Airbus flight manual: Don’t use rudder while in flight.
They recovered the vertical stabilizer intact on this last accident over the Atlantic, rudder and all.
New Dreamliner flight manual update: Do not pressurize cabin during flight operations.
LOL
All silliness aside, I will never fly in a pressurized airplane whose fuselage is manufactured with composites. Nor will I allow, if possible, anybody in my family. Wings included. As I said, in a perfect world it is great stuff. But in the real world of commercial aviation, 15 years down the road, sold two or three times and maintained by Mexicans at some Mexican facility who are not even licensed A&E’s glueing a crack in a composite fuselage with 5 minute epoxy. Similar things are happening right now, just not composite fuselages yet.
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