Sunday, July 8, 2007

Dreamliner...

The Boeing Dreamliner is getting a lot of press now that it's about to actually be released. I'm glad Boeing is finally showing some signs of life. However I have my doubts about the materials. I know everything eventually fatigues out. Carbon composite frames like they are using for the plane will too. In the biking world companies like Trek have given lifetime warranties out on their carbon frames. I don't know if they still are and whether they lost money doing so. I do know that it seems like every carbon framed bike that gets much use falls apart. The frames just collapse with fatigue after a few years and the rider is left with having to walk home if able. Hopefully these new aircraft from Boeing can be monitored closely and their parts replaced well before fatigue causes real problems. Because I don't think passengers will be able to walk home when the plane breaks apart at 30,000 feet.
With press releases like the following which don't mention anything negative, in fact say just the opposite, that these new plastics never fail and blah blah blah it makes me want to avoid the dreamliner forever. I wonder how long it will be until the plane is dubbed the "nightmare".

http://www.afp.com/english/news/stories/070707184635.vp7850dy.html
New materials are star of 'Dreamliner': Boeing
07/07/2007 18h50
Jeff Hawk, Boeing's director of certification, Government relations and environment for the 787 program, told journalists he was unaware of any drawbacks to using composites.

Twice as strong as conventional materials, lighter than aluminium and offering greater resistance to fire, state-of-the-art carbon fibre will be used in the fuselage of a commercial passenger jet for the first time with the 787, a medium-to-long range plane capable of seating up to 330 people.

The lighter weight of the aircraft's component materials allow the Dreamliner to make massive savings on fuel -- around 20 percent less than similar-sized planes -- according to Boeing.

The durability of composites will also lead to lower maintenance costs, officials say. "Composites don't fatigue," said Tom Cogan, the 787's chief engineer. "You don't have the maintenance problem. Aluminum can corrode, composites don't corrode."

Although Boeing declined to predict the lifespan of a 787, they said they expected it to outlast existing passenger jets, which typically remain in service for between 20 to 30 years.

Asked about possible weaknesses in the new materials, Boeing said composites had been used in the beams of its long-distance 777 for 13 years and were still in immaculate condition.

"The way it held up over time was exceptional," Cogan said. "The floor beam was pristine after 12 years."


Seems to me they must have hired Ex-Bush Administration Neo Cons to do their advertising...




http://english.aljazeera.net/NR/exeres/6EB73710-538F-411A-8EAD-2468C299A318.htm


The Dreamliner uses plastic composites instead of aluminum.

Up to 50 per cent of the primary structure, including the fuselage and wing, will be made of composites such as carbon-fibre, which reduce the weight of the aircraft.

Boeing said in a statement ahead of the Dreamliner's unveiling: "By manufacturing a one-piece fuselage section, we are eliminating 1,500 aluminum sheets and 40,000 to 50,000 fasteners.

"The airplane will use 20 per cent less fuel for comparable missions than today's similarly sized airplane."


So what tests has this plane gone through? What happens when the wings are covered in ice and it's 30 below? I can easily imagine the wings shattering in these conditions. Now what happens to these wings when they are hit by hail? At 300mph? In various temperatures. What happens when the aircraft is hit by lightning? Do they melt like normal plastic toys? Do their properties change requiring the airplane to be disposed of? I don't see anybody talking about these obvious scenarios. I suspect Boeing will soon become a footnote in history.

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