Posted on 09/18/2007 10:46:46 AM PDT by skeptoid
Former CBS newsman and anchor Dan Rather, now with HDNet, will have a special report on the 787 that airs Tuesday, Sept. 18. The subject is whether new composite jets like the 787 are safe.
Boeing recently completed a test in which a section of the 787 composite fuselage was dropped from a height of 15 feet to simulate a crash landing. Boeing has said the test was a success.
This is part of the Associated Press story the P-I ran about that test:
The Boeing Co. said Thursday that results from a recent test on a 787 fuselage section matched computer predictions, eliminating the need for some physical tests.
(Excerpt) Read more at blog.seattlepi.nwsource.com ...
“Don’t most planes fly higher than that?’
Well, at some point before it crashes, every plane will be at fifteen feet...
“As far as I’m concerned the FAA should be requiring complete physical testing to gain certification of airworthiness.”
See FAR Part 25.
“Today’s composites include some pretty astounding stuff”
And some of the most expensive. I saw a composite paddle at the kayak shop for $365 as opposed to my $49.95 plastic model.
Pretty cool. 150% is what they’re required to survive. They were speculating that the 787’s carbon wings might actually touch at top and never break (strong, but flexible). But if they did, the explosion would be pretty impressive as carbon fiber particles shoot everywhere.
Really? F=MA, 15 feet is a long way to accelerate when its 32.2 ft/sec^2. Falling from 15 feet is more than enough to kill ya man.
Is it just me or do they now shatter into bits during an accident?
They couldn’t test the wings to failure. The bending machine ran out of its range of motion before the wings broke. :p
I know nothing of composites, but I do know aluminum and rivets. Sloppy, high maintenance and prone to corrosion in places you can’t see.
It is well past time for new technology in airframe manufacture.
Rather works for Mark Cuban now, ‘nuff said.
No aircraft can withstand a "drop test" from much more than 15 feet. Keep in mind this is a pure "drop" test, not cushioned by ground effect or any aerodynamics whatsoever. I know NASA did testing on GA fuselages several years ago that were swung on a trapeze rig from only about 75 feet so they hit at an angle, and in most cases the internal seat structures failed and would have killed the pax, even though the fuselage was basically in one piece afterward. A pure drop from 15 feet onto a solid surface, with no suspension, no human leg bending, nothing to gradually slow the stop at the end is extremely severe.
Why would anyone believe Dan Rather?
Yes, but the last time I checked, Indy cars don’t fly through hail at 600 MPH, or go through thunderstorms and get hit by lightning etc......
The F-18 and F-22 both fly in a pretty nasty environment... and both have more than 20% of their structural material made from composite material.
50 percent of the Dreamliner is composite, including major structural elements like the fuselage, wings, and tail. One seats 1 passenger, the other 300. The 787’s pricetag is $150 mil per plane, the F-22 is currently running $361 mil per plane. I hope the disparate prices reflect the F-22 being a more robust airframe, although I doubt it.
System costs are most of the reason. Airliners can install off-the-shelf avionics and flight controls that are identical, or almost identical, as other aircraft. While the various systems in fighters are very unique and require development from scratch. I think the F-22 in particular has some flight control techniques that are very unique and undoubtedly took a large effort to develop.
We don't build the best warplanes in the world by being cheap.
You might be surprised how many veteran pilots will no longer accept duty flying Airbus because of that. The FAA’s response was to restrict full scale rudder deflections on ALL aircraft with composite rudders. It’s like saying you have 50,000 #’s of thrust, but you can only use 30,000, even if it means you are going to fly into that mountain up ahead. Absolutely crazy.
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