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Boeing Dreamliner Safety Concerns Are Specious
SoyChemist writes in to note his article at Wired Science on the uproar Dan Rather has stirred up with his claim that Boeing's new 787 Dreamliner aircraft may be unsafe. "Dozens of news agencies have jumped on the bandwagon. Most of them are reporting that the carbon fiber frame may not be as sturdy as aluminum. Few have bothered to question Rather's claims that the composite materials are brittle, more likely to shatter on impact, and prone to emit poisonous chemicals when ignited. While there is a lot of weight behind the argument that composite materials are not as well-studied as aircraft aluminum, the reasoning behind the flurry of recent articles may be faulty. The very title of Rather's story, Plastic Planes, indicates a lack of grounding in science. Perhaps the greatest concern should be how well the plane will hold up to water. Because they are vulnerable to slow and steady degradation by moisture, the new materials may not last as long as aluminum. Testing them for wear and tear will be more difficult too."
More "Fake But Accurate" reporting.
In case of fire, do not use elevator. Use water!
Is that really the biggest concern at that point? Seriously?
I heard he has an email from Pres. Bush that he sent Boeing in 1945 proving that they knew the plane was unsafe.
It's hard to believe that's how Micronians are made. Why don't we see it right now by having you both kiss one another?
People have been voicing these concerns for years.
Dan Rather falsely reporting something? I'm shocked, SHOCKED! Well, not that shocked.
Well, it has never been successfully tested.
...Dan Rather is making good use of his PH. D.'s in Materials Science and Molecular Chemistry when he says these things.
Really, Dan is just cranky after being outed by CBS for his lack of thorough background information checking, so he's taking it out on Boeing, probably because he had to wait for a flight at JFK.
GetOuttaMySpace - The Anti-Social Network
Carbon fiber more brittle than Aluminum? So's diamond...What's your point? Carbon fiber is also a lot more flexible than aluminum and it's lighter. There are pros and cons of every material. It produces chemicals when it burns? Like inhaling toxic smoke is going to be your big worry if the PLANE is ON FIRE.
This kind of crap is infuriating for airline companies...It doesn't take much at all to kill a whole line of planes, just the vague reputation for being unsafe. A report like this, based on a flawed understanding of Carbon vs Aluminum where the "reporter" doesn't even grasp the real issue, could do real harm.
ad logicam Claiming a proposition is false because it was presented as the conclusion of a fallacious argument.
- Buying Madonna's book: Screwing for Virginity.
- Buying MS Vista for it's speed and congeniality.
Seriously folks, Dan Rather has about as much common sense as a Bugby.This is the guy that went on the airwaves with a "memo" supposedly typed in the 1970's, with proportional fonts and different-font sized superscripts! I would not trust someone like that to tell me it's raining.
Carbon-fiber composite construction has been around for going on forty years now. It's been accellerator tested in hot humid ovens and passed with darn good results. Boeing doesn't make junk. And airframes are warranted for tens of thousands of Hobbs clock hours, so the airlines are not at risk, they're voting with their checkbooks.
Reember, news is no longer about full and honest reporting, it is about money. Quick bucks by sensational stories. If CBS, NBC, etc pick up on this, they pay HDNet for the rights and footage, and in turn sell adspace for their own reports. None of them care if it's right, they care of it pads the wallet.
Karma Whoring for Fun and Profit.
If you go "this is unsafe!" and you were right, and you can go I told you so, and score a political victory.
If you go "this is unsafe!" and you were wrong, you can go well my conserns were addressed and score a political victory.
If you go "this is safe!" and it is safe. Nothing really happends no creditability loss or gained.
If you go "this is safe!" and it was found unsafe. You get fired, invistagations, rumors you were in colution with with contrators....
So if you were trying to run or stay in office what will you demmand.
Government is a failure driven buisness it is what you do wrong that hurts you and if enough people above you were fired then you finally get promoted. So Screamming and yelling and making false accuasations and make the world seem like an unbarable place to live is the best thing you can do for your job.
If something is so important that you feel the need to post it on the internet... It probably isn't that important.
Isn't the curing process for carbon fiber a few thousand degrees? Wouldn't fire have to be hotter then the curing process before carbon fiber would burn or smolder?
There are no loopholes. It's either legal or it's not.
Carbon fiber can fail, but when it does fail it tends to do so suddenly and violently. Where metals bend Carbon fiber tends to explode. Though i have also seen the films of boeing stress testing the 787's wing bend. With far more bend than a metal wing could handle. As others have pointed out weathering may also limit the useful life of the parts.
In the End CArbon fiber isn't better or worse than a metal plane. It's just different with different things that can go wrong.
i thought once I was found, but it was only a dream.
Almost any boat you're likely to see in a private marina probably has a hull made of fiberglass, an epoxy/fiber composite. Working with composites around moisture is mostly just a matter of attention to detail and maintenance. Carbon, kevlar, and fiberglass epoxy composites have been used for decades in whitewater and flatwater kayaking and canoeing. With proper maintenance a single boat can easily last that long.
Build a man a fire, he's warm for one night. Set him on fire, and he's warm for the rest of his life.
Next thing you know, the reporters will claim that Reardon Metal is unsafe! DONT GET ON THAT TRAIN, DAGNY TAGGART! :O
OK, I know someone out there is going to lable me a Randite (or some such) but this is exactly the kind of fud campaign that Hank Reardon faced when he introduced "Reardon metal" in the book "Atlas Shrugged" I mention this because the motivations of the FUD campaigners in that book were essentially - I don't own a piece of Reardons Pie, so I am going to fling poo and see what sticks. Maybe Rather is upset because his Alcoa stock price is likely to be negatively influenced by this plane - if it is a big hit.
'Only a Barbarian believes that his tribes customs are the laws of nature'
they should put on the disclaimer... "More likely to shatter on impact, if you are lucky enough to have survived it!"
:)
**My personal disclaimer - I'm not happy with airlines, so don't look at my like that!
Next thing you know he'll be tossing words like "hella" and "truthiness" around.
And it was built in the early 1980's. You would think that in a plane whose computers limit turns to 9g's -- not because of the airframe, but because of the stresses on the pilot -- they would have concerns over strength. But that is not so.
One concern the USAF had with the F-16 was that in the event of a crash, a cloud of electrically conductive carbon fibers would settle over the base, shorting out anything electrical. Judging by the F-16 we had burn on the taxiway at Hahn AB in 1985, that wasn't the case.
Chip H.
If you ask me, Dan's gotten himself in more trouble than a chipmunk in a tire factory.
Dan's a little distracted right now as he's busy SCOing CBS. You see, it was their fault that he lied about the fake Bush memo and therefore they should give him $70M.
Does Rather have credibility with anyone now, or is this just an old man past his glory days that desperately wants to remain relevant and visible?
Dewey, what part of this looks like authorities should be involved?
What they don't mention is that, while the testing schedule is shorter in terms of calendar days, Boeing is logging just as many, if not more, flight hours with the 787 test aircraft as they have with earlier projects. The accelerated schedule is to meet their delivery deadline, but all the requisite tests are still being done.
Boeing knows that the health of the company for the next 10-20 years rests with this aircraft. Airbus, despite its problems with the A380, isn't going to cease being a fierce competitor. If Boeing screws this project up, and gets a lot of bad PR from an aircraft failure, they'll be lucky to survive. With so much at stake, I trust them to do their jobs right.
Airbus have been using composite parts in their aircraft for quite a while. However, as it turns out, this hasn't been a problem free experience. Notable examples are Air Transat flight 961 where the composite rudder fell off the Airbus A310 in mid-flight. Also, more tragically, American Airlines flight 587 crashed after the co-pilot made several rudder reversals resulting in the composite tail fin of the A300-600 snapping off.
I hope Boeing have learned from these accidents.
Since they've built ONE so far and they are trying to make that one fly. The 787 static wing load test isn't for months. Perhaps you're thinking of the 777 static test, which is the only one to my knowledge that has been videoed and released. Posting from a Boeing computer...
As we know from Battlestar Galactica, making the hull from composites will make it invisible to Radar..
thus air traffic control will be unable to find them and guide traffic around them.
"Waste not one watt!" - CZ
I hate articles like this...doesn't anyone actually use, you know, MATH to quantify terms like "safe" and "unsafe", without just throwing around FUD like this? BY FAR, the most dangerous thing we all do everyday is drive our cars around, which account for 44.3% of all accidental deaths in this country. This is followed by "Unspecified non-transport accidents" at 17.6%, and Falls at 13.6%.
Death stats found here http://www.the-eggman.com/writings/death_stats.html.
Aircraft deaths do not even make the list. How can something that accounts for less then 0.1% of all accidental deaths be called "unsafe"?
never bring a twinkie to a food fight.
Has anyone told Kimi Raikonen, Lewis Hamilton and Fernando Alonso how unsafe composite materials are? At the Montreal F1 race Robert Kubica demonstrated how fragile and prone to fire they are when he took a 150 mph flight into the wall.
This helps Boeing. All it has to do is present counter arguments and have FAA representatives state publicly that the plane is secure. It's just good publicity. Airbus is quiet. If it had started making some waves about the current statements by Rather, then it would have been interesting. Are there no simulation (VR) conducted about crashes occurring? Boeing should release the results and even make the risk analysis report public (at least part of it), as a slap in the face of all those who believe the plane is not ready.
Do I require the c-sig package to have a signature?
Oh Dear, here we go again ...
Carbon fibre, Aramid and glass fiber are the predominant construction materials in sailplanes. They all have a long, proven track record of reliability and endurance.
When a plane crashes, toxic fumes (emitted mostly by the material's matrix, usually epoxy raisin) will probably be the least of your problems.
Carbon fibre will burn to C02, because, as the name implies, it consists of carbon.
PS: I know what I'm talking about, because we build sailplane prototypes at the University of Darmstadt (the kind where you can actually sit in and fly).
This is the guy that went on the airwaves with a "memo" supposedly typed in the 1970's, with proportional fonts and different-font sized superscripts! I would not trust someone like that to tell me it's raining.
It wasn't just the fonts. It was that, you could type the document into Word, and it overlayed the Rathergate document exactly.
This is my sig.
Yeah, but epoxy/fibre boats suffer from "Boat Pox", where blisters form under the skin and the GRP delaminates. Now, if that happens in a fibre wing, I suspect there would be disastrous consequences.
Would you care to reassure me in some other way please?
Deleted
The first aluminum pressurized passenger aircraft were not safe either. There was a learning curve in building large, pressurized metal planes. Ref: http://en.wikipedia.org/wiki/De_Havilland_Comet
There is a learning curve for working with composites too. We are fairly far along in learning to build small (non-pressurized) aircraft, or parts of aircraft out of various composite materials, but just as in the time of the Comet, we are early in the curve for building large, pressurized aircraft. There will be "educational moments" along this curve.
Other than your coming grip about W, what else do you claim to be false?
As to this story, do note that Weldon (with rather simply reporting) is saying that composites are NOT as safe as aluminum in a crash, which is almost certainly true. It most likely will shatter with the right impact. And Metal will be worse in certain conditions. Fox makes it worse with a supposed FAA statement (which is most likely not what was said):
Federal Aviation Administration (FAA) must find the 787 to be as crashworthy as aluminum planes, and the plane was doing well in those tests so far.
FAA does not require that this be as GOOD as aluminum. After all that makes it sound like aluminum is the minimum. That is ridiculous. The FAA has a standard of what they are willing to accept for a crash. Aluminum will fit the bill for a lot of it. But I would guess, so will composites, just in different ways. But to say that Rather is FAKING this is disenginous. I have little doubt that the engineer is correct in saying that composites will not do as well as metal. In fact, I would suggest iron IFF crash worthiness is the only point of interest.
I prefer the "u" in honour as it seems to be missing these days.
I should hope so, what would be the point of having a plane that you can barely move in?
Summation 2
I ride metal bicycles, which slowly degrade after a point you're putting significant energy into flexing the frame because it looses stiffness. At or before this point is the time to buy a new bike. I've heard from people who ride composites that they tend to fail suddenly, like during a ride.
Anyway, the aerospace people have been using composites for longer than the bicycle people, so they've developed things like X and Gamma ray machines to look for defects before they become a problem. If Boeing can develop an inspection system that doesn't cost more than the new materials save, then they win, with no loss to safety.
People have suggested that since military aircraft have used composites, they must be safe. Yes, but... The Military needs planes that have certain performance characteristics, and cost is secondary.
All ideas^H^H^H^H^Hprocesses in this post are Patent Pending. (as well as the process of patenting all postings)
"I hope Boeing have learned from these accidents."
To my knowledge, they haven't because they didn't make those design decisions in the first place, knowing that there was a risk to them and deciding to avoid them in advance rather than risk learning from a bad decision the hard way.
Boeing engineers are incredibly conservative. Airbus is a bit more aggressive - brought to you by most of the same companies that brought you Ariane 5...
As an example: Different design teams made both the hardware and software for each of the triple redundant flight computers on a 777. The teams were not allowed to have any contact whatsoever, even personal contact outside of work. Meanwhile, the first Ariane 5 went BOOM because all three (identical) flight computers crashed in sequence due to the same software bug.
I've flown a lot, and am in general not afraid of flying, except when I step onto an Airbus. Then I get a bit nervous...
retrorocket.o not found, launch anyway?
Carbon Fiber can be constructed to break apart in order to dissipate energy on high impact collisions. Just look at this year's Canadian Grand Prix to see the results of Carbon Fiber in a crash. It contributed to saving the life of a driver. The parts that were supposed to break away did. The parts that weren't did not. If I'm falling out of the sky in a jet, the last think on my mind will be reviewing the finer points of the composite construction of the plane.
The article criticizing the concerns merely says that they "may" be faulty. That hardly qualifies this threads title to claim that the concerns raised are specious. Just because some aircraft utilizing various amounts of carbon have proven to be safe does not imply that all carbon aircraft are therefore safe, especially one that may not have been adequately tested.
OK, I have this weird habit of collecting cultural references to Abe Lincoln ... if you don't mind, where did you derive your sig from, or did you make it up? thanks
Aircraft deaths do not even make the list. How can something that accounts for less then 0.1% of all accidental deaths be called "unsafe"?
While I find your overall point valid, the above has an easy answer: popularity. It is obviously unsafe to mechanically force the ingestion of 100 pounds of live fire ants... However, this particular act probably accounts for no deaths at all, 0.0%.
I am a viral sig. Please help me spread.
Deleted
Well, essentially all planes are "unsafe" to some degree. Especially when the pilot has had his morning whiskey...
It only works that way in different load directions. You can take a sheet of CF in a typical layer configuration (say a 45/90/135) and bend it 45 degrees or more and it won't break or even look like it was bent when you return it to its former shape. But if you pull on it it doesn't stretch like aluminum. What people misunderstand is that because it doesn't stretch, they think it is more prone to failure which just isn't true. It is absorbing the same (or more) energy but it doesn't exhibit the same behavior while doing so. Aluminum will fail and snap also, but people are more comfortable with it stretching first because that's what they are used to seeing. It doesn't make it better, just different.
The types of CF composite that degrade faster are the ones where the resin doesn't have a UV inhibitor in it. UV degrades the resin just like it does to any plastic but with proper protection that isn't a problem. Once this was understood companies developed UV inhibitors for the resins to make them resistant to UV degradation. And you can bet the farm on a $150+ million dollar plane being adequately protected. There is no reason to think that they won't last just as long as an aluminum plane. Never mind that the resin only carries a tiny fraction of the load, in the directions the fibers aren't laid up for. Meaning the resin is mainly there to keep the material from delaminating.
Though some may not know it, but as aluminum oxidizes over time it becomes aluminum oxide which is more brittle and prone to fracture. So you face the same problem with aluminum, but it is adequately protected and hasn't been a problem for the many many years that commercial aircraft have been flying. Just like fiberglass boats, adequately protected and maintained they last a long time.
But what do I know, I'm just an aerospace engineer with some composite materials training. I should leave the science to Dan Rather.
The whole situation kind of reminds me of the book Airframe by Michael Crichton (which I enjoyed a lot!).
Give me a break... Carbon fiber has been used in aircraft for awhile already - many of the private jets now are made of them. McClauren F1 is made of them, along with many other exotic sports cars. Gizmondo survived his crash in his carbon fiber sports car accident. Some computers are now made of carbon fiber housing to safe weight, Motion Computing Tablets for example.
Reminds me the beating that fiberglass took when it started becoming widely used in the 80's, then was found just as good. (now being replaced by carbon fiber which is stronger)
any many many other things that are perfectly reliable
Dan Rather's claims are based on a report he received from 1972 detailing the flaws and dangers of carbon fiber airframes. The report used proportional fonts, kerning, and a typeface that was not available until much later.
When questioned about these inconsistencies, Rather declared "I believe this story is true! I believe it in my heart! I stand by my pres.. errr, I mean Boeing, but I feel this story is true!"
Boeing was not available for comment.
Muslim community leaders warn of backlash from tomorrow morning's terrorist attack.
For the 777, one test Boeing performed was bending the wing to 150% of its maximum rated load to make sure the wing was structurally sound. The all-aluminum wing shattered at 153%, which makes for a great video: Boeing 777 Wing Ultimate Load Test. (The video is from the PBS documentary miniseries Twenty-First Century Jet.)
When I'm flying and I see the wing bobbing up and down outside my window, I try not to think about seeing this video. (Of course, I know the loads are different, but then I have to convince my reptile brain.)
The comments in this thread are just more evidence for why we should leave the aircraft construction up to the engineers and not try to figure things out here.
Carbon fiber is a VERY active area of research, and it is definitely true that more is known about aluminum than CF structures, but this is for the simple fact that aluminum is about 10x simpler to understand and model than CF. You are talking about a metal that is isotropic (material properties the same no matter what direction you measure them) versus two different polymers, bonded together. Composite mechanics are incredibly complex, but that doesn't mean we don't understand them enough to make them safe. It only means that we have to use larger safety margins in our designs. As research continues, you will not see airplanes get safer, only cheaper and lighter. Safety is driven by FAA regs, and performance that is driven by material knowledge.
In general, carbon fiber is stiffer and stronger than aluminum. This means that you can make the plane weigh less and flex more. Good, right? It also will have better fatigue properties than Aluminum, since it does not have to deal with crack propagation. Aluminum will fail catastrophically, while CF will go gradually. Chances are that you will detect a CF failure long before it becomes a safety problem, as long as you use those fancy infrared/X-ray/gamma ray inspection devices. For those concerned about "water fatigue", there are a number of industry standard tests to measure this degredation, and it is included with every roll of CF that you order. It's definitely not something they haven't thought of.
The FAA has some of the most stringent regulations of any government agency when it comes to airplanes. The chances of an unsafe product making it to market are very low, simply because of the maintenance required and number of test hours needed. If you remember scandals of the past, they all come from companies either cheating the regulations or the regs failing to be applied. Please don't get riled up unless one of these two things is happening.
The Board found that the composite material used in constructing the vertical stabilizer was not a factor in the accident because the tail failed well beyond its certificated and design limits.
The Air Transat incident is looking more and more likely that it was caused by leaking hydraulic fluid causing delamination in the composites to the point of failure.
He's so desperate to be relevant again. Sucks to go out as a shill for a political candidate, but it's well-deserved for a long career of slanting the news to suit his bias.
You are in a maze of twisty little passages, all alike.
I Tivo skimmed Rather's report. Junk.
I was very disappointed that they ommitted other composite aircraft. The vast majority of homebuilts are now composite. This transition started in the 1970s. Not the exact same tech, as airliners are oven cured carbon fiber and homebuilts are room-temp cured glass... but still, lots of airframe experience and lots of flight hours.
Also check out the Beech Starship. This is a turboprop and used oven cured carbon extensivly. The aircraft was an economic failure; one primary reason was the FAA didn't believe in composites and forced lots of compromises into the airframe, such as aluminum spars and lightning strike channels.
That, and the scare mongering about compsosite rudders breaking... many more aluminum parts have departed aircraft than the one or two incidents they could dig up on composites. If you've ridden on nearly any airliner built in the last 10 years, you've ridden with composite control surfaces.
and a bike mechanic, I have studied the aspects of carbon frame and fork reliability very thoroughly. My verdict is: a carbon fork will work for thousands or tens of thousands of kilometers, and never ever show any signs that something's wrong, and then one day it will snap, and the rider could die (when the front wheel looses traction, you're going down. Unlike the rear wheel, in which case you have a chance to control the bike to some extent, and control the fall (I said "you have a chance", not certainty)). So many cyclists have died because of carbon fiber fork failures, and even very experienced ones. The problem is, as I said, that it's impossible to predict a cabron fiber bike part failure. With aluminum it's easier, because usually there are tell-tale signs (now, whether you'll check the part or the frame for them, it's another story). With steel and titanium it's even simpler, as these materials will usually allow a cyclist ample time before a breech develops into a full crack.
So, I do believe the technology of carbon fiber composites is very promising, but they still haven't built a carbon fiber fork I'd ride with full confidence.
That said, understand that the chances of dieing from a carbon fiber fork failure are pretty small, but sadly, completely unpredictable.
"The agriculture ministry is not in charge of Gundam" - Japanese ministry official.
787 isn't a super jumbo. It is designed to carry around 310 passengers efficiently 747-400 carries upwards of 580 people packed into domestic flight style sardine load out. It may crash spectacularly, but you will need 2 or more to crash into each other to make it up to the highest body count (surpassing Pan Am/KLM 583)
If you go to the article on WIRED, you are presented with the text accompanied by a picture of a shiny new boeing airliner. Presumably we are supposed to infer that the picture shows the aircraft concerned, perhaps rendered using CGI? In fact, mouseover the image and a balloon help pops up saying 'dreamliner', and the file is called "dreamliner.jpg".
However if I'm not very much mistaken, the picture is not a 787/dreamliner, but rather a Boeing 737/700 - a much smaller jet made mostly from more conventional materials. In fact, it's the same image used on the 737 wikipedia page. Careless journalism from WIRED too, perhaps?
It has been reported that, in fact, a Dreamliner crashed in Peru and then made everyone in the surrounding villages sick http://www.guardian.co.uk/space/article/0,,2171920,00.html. Initially, it was thought that it was some strange meteorite or UFO. But, no, it was a DREAMLINER!
The Certification process for composite airframes has higher structural requirements than for aluminum airframes to address most of the concerns raised here. The requirements include testing the materials at high temperatures after being saturated with moisture (FAR part 25.603). The result is that even in the worst conditions, the composite airframe is as strong as a comparable aluminum airframe. In normal operations the carbon 787 will be significantly stronger than its aluminum brethren.
Why? Apart from the low accident rates on airplanes in the first place, you are flying a specific model - some models from Airbus (e.g. A340) have way better records than some from Boeing (e.g. 747), and vice versa. (Source: http://www.airsafe.com/events/models/rate_mod.htm )
Apart from airplane models, crew and maintenance play a big role, too. It would make more sense to look at the records for airlines, since those by necessity combine all of three factors.
...crashes into a mountain at 500mph, does it really matter that the subsequent fumes may be toxic?
After he had been told by a pilot to NEVER do that again, and one pilot refused to ever fly with him again.
The guy, through a combination of his own inflated ego and the flawed American Airlines Advanced Aircraft Maneuvering Program (AAMP) killed everyone onboard that flight. What happened was in the AAMP one of the things taught was a "Wake Turbulence Avoidance Manuver" in a commercial flight simulator. The problem was they started with the simulation paused. Some pilots figured out that if you start with the rudder at full deflection with the sim paused, then as soon as it unpaused input full opposite rudder you could "fool" the sim into doing what it wanted. So then when he was flying the departure on flight 587, they encountered wake turbulence and he did the same damned thing, threw the rudder hard over, bang-bang-bang. Ripped the tail right off, not just the rudder, the whole vertical tail. An aluminum tail would have snapped off just the same.
If anything, an argument was made that the flight control system shouldn't have allowed such large rudder deflections, the trouble was the deflection angle was safe, didn't apply an unacceptable load to the tail. The load came from the cycle of full deflection one way to full deflection the other way, like rocking a car out of a rut. The momentum of the yaw combined with the full opposite rudder input snapped the tail off.
Coding with assembly is like playing with Legos. Coding an application in assembly is like building a car with Legos.
Is that bike shops dont have neutron backscatter machines and x-rays to do non-destructive tests on carbon fiber parts.
Seriously, if you did preventative maintenance and checks on those carbon fiber parts you'd know when they had exceeded their service life long before they snapped.
This space for rent.
....that anyone is stupid enough to believe anything Dan Rather says.
More than 60,000 Windows programs won't run on Linux.
I would get nervous if I ever stepped into something which wasn't made in the good ol' US of A. All foreigners are the same, stealing our ideas and selling us trash back.
Hell, we invented the airplane in the first place! We should never have let them have the technology. If someone hadn't sold it to them in the first place they'd still be crawling around on the ground.
I'd sue him for $70M.
Neil Postman wrote a book called "How To Watch The TV News" in which he proposed that if a media commentator doesn't have a degree in the subject under discussion, a big flashing red sign should be displayed in the background, that says "I don't know what I'm talking about."
Reporters aren't scientists, and they don't know science. What they know is how to write stories that people want to read, because that's their business. I'm not exactly blaming the reporters: they're doing what they're paid to do. The problem is that the people reading the material don't know that reporters don't actually understand the issues, or that the people watching the TV shows let themselves be biased by reporters who don't actually understand the issues.
Carbon fiber/epoxy aircraft can burn, sure. They release toxic compounds when they burn. So does aluminum, and aluminum fires, while rare, are devastating. Carbon fiber has excellent fatigue characteristics: aircraft built from it will probably put 100,000 hours on airframes without any problems, since some carbon fiber fatigue testing setups have had the steel test setup fatigue-fail before the airframe under test while there are lots of aluminum aircraft out there which have failed catastrophically because of fatigue.
People often claim that carbon fiber fails catastrophically while aluminum fails softly. That hasn't been my experience. I spent years racing mountain bikes, and the majority of aluminum failures I had -- although in every case the crack had started well before the failure -- went from imperceptible to completely broken far faster than I could react to, when I was going comparatively slowly at net-near-zero elevation. (RMS elevation on a mountain bike during a race is roughly +1cm, I think...) In contrast, I've had two carbon fiber components fail just as suddenly and one fail comparatively slowly: from the point where it started to break to the point where I got the bike stopped was maybe ten seconds and it was still hanging together by threads of carbon.
When I build a plane it's going to be welded steel tubing, which can be designed with no fatigue limit, but I'd prefer carbon fiber over aluminum if I had to choose.
Nostalgia's not what it used to be.
Did you know that the Boeing 777 vertical and horizontal stabilizers, as well as rudders, elevators, and wing control surfaces, are all CFRP composite structures? They seem to have had no service difficulty. Perhaps the difficulty that the Airbus A300 series is related more to their human factors philosophy of not providing adequate force feedback to the pilot' controls, rather than their choice of materials.
The Air Force & National Guard have just about run the crap out of the old F-16 fleet too. More than half of them are showing the signs of fatigue and need to be replaced asap. The support contractors who maintain them for our military have been voicing lots of concerns over the past 3 or 4 years that some onerous airworthiness and structural integrity issues are beginning to show up in the most heavily used airframe specimens, especially metal fatigue in critical components and the F-16 fleet's days need to be numbered pretty short. Hopefully, enough of the fleet should hold up fine until they can all be replaced by the F-35s.
The F-15s are suffering from serious corrosion and metal fatigue problems and their replacement, the F-22 Raptor are too expensive and not being built fast enough.
General Electric's GEnx is going to be used on the Dreamliner. It has a composite fan case and composite fan blades with a titanium leading edge. As part of the FAA certification for the engine to be certified to fly, it must withstand several tests: endurance, icing, foreign object ingestion, crosswind, and blade-out. -Endurance runs the engine at take-off power for over a week straight. -Icing involves shooting ice into the engine until it stalls or until you can't shoot a larger amount of ice. This is also done with water. The GEnx did not stall on this test. -Foreign Object Ingestion is where organic objects are shot into the engine (birds of various sizes). Think meat grinder. -Crosswind involves applying winds from non-standard directions. Fairly straight forward. -Blade-out is where an explosive charge is placed in the forward fan and detonated causing a blade to shoot out and get sucked into the engine. By FAA regulations the forward fan case and engine must completely contain the failure. The end result is a destroyed engine. For the GEnx, I have personally seen the fan case from the blade-out, and the carbon-fibre fan case withstood the blade-out on its first run. This truly attests to the strength of composites. Just my 2 cents.
Am I the only one worried that Boeing describes the technology used to build the 787 as "groundbreaking"?
~ Better a freak than a sheep. ~
Aluminum isn't all that great either. If it gets hot, it loses most of its strength and the wings will just droop and fall off. That's not the worst, though. Aluminum is a metal that is prone to cracking under stress. This is an especially bad thing if there is an undetected crack in a critical part that suddenly grows and...the wings fall off or the fuselage blows out, maybe carrying people inside out of the plane, too. And then there's corrosion. Aluminum will oxidize to the useless oxide form when exposed to moisture and oxygen, two ubiquitous substances around airplanes. Corrosion can build up over time, slowly weakening critical parts over time until, one day, the wings fall off. See a pattern here? And then, if theres' a fire, aluminum will actually 'burn' and turn to dust as it oxidizes under high temperatures. Of course, by this time, the wings have probably already fallen off.
A much safer material to use for airplanes is wood, which doesn't oxidize at ambient temperatures, doesn't weaken when heated, and doesn't allow crack propagation if properly designed, Of course, it will oxidize under the right conditions but nothing's absolutely perfect. Finally, wood will allow the use of high tech fabrics, instead of dangerous aluminum skins, to cover skin surfaces and the fabric can be covered with special surface coatings to reduce air permeability. Best of all, there is some operating history with using wood and fabrics for aviation purposes to provide designers to proceed with confidence! After all, when something works well, why bother assuming a lot of new risk?
/sarcasm mode=on
/sarcasm mode=off
Oh Dear, considering all that fuel carried onboard your sailplanes....
Carbon fiber itself isn't the concern for the toxic fumes, the epoxy resin glues that make the carbon fibers useful, are the source of the toxic fumes, not the carbon fibers themselves.
Obviously you DON'T know what you're talking about here, because the catastrophic high-speed, make-a-new-smoking-hole-in-the-ground-crash isn't the kind of airplane crashworthiness we're concerned with here. No aircraft construction materials can survive that kind of crash. In that kind of crash, you're gonna die and that's that... the toxic fume issue is irrelevant. What we're concerned with here, is the kind of "crash" where the impact forces are not so bad (hard landings, flip-overs, landing gear collapses, off-airport dead-stick landings on rough terrain, etc) that are normally very well survivable except when fuel tanks rupture and the ship begins to burn before all occupants can get out. Those kinds of "crashes" happen a lot more frequently than augering a plane into the ground like a big lawn dart. When the aircraft's structural materials start to burn, the toxic fumes can be the deciding factor if they overwhelm the people before they could escape what would otherwise be an escapable post-crash fire once the aircraft has stopped moving on the ground. This is our primary concern here.
PS: I know what I'm talking about, because I build metal airplanes (the kind where you can actually sit in and fly... plus carry several passengers with you).
"...and green Rearedon metal is crappy, too! We know it!"
(-1: Post disagrees with my already-settled worldview) is not a valid mod option.
"Never let the facts interfere with a good story." - Dan Rather
Ibid.
What's the current survival rate of place crashes? Like
I say lets not keep focusing on crash scenarios and focus on the new features that can keep the plane in the air like the new improved navigation system and various other major design enhancements.
I'll take a plane that can stay in the air easier during bad weather over a plane thats safer to crash in, but is harder to keep in the air.
.. when air planes DUMP FUEL before landing, it is NOT for the risk of FIRE, it is to REDUCE WEIGHT to a safe level.
http://www.rense.com/general79/wdx1.htm
...was not a sufficiently studied material to be safe for bridge construction.
Nervous Nellies. Holding up progress with silly demands for a risk-free existence.
Oh, wait...
"How to Do Nothing," kids activities, back in print!
My dad worked for boeing and used to tell me stories of how airplane safety came to be. Basically an giant engnineering system to learn from every crash. One of the first stories he told me was about how they learned about metal fatigue when the early aluminum planes started dropping wings. At the time everyone though alumiunm would be a great airlpane construction material just like they think carbon fiber is now. No one anticipated what a disaster it turned out to be. Of course that was then. And now Aluminum is a great material, once they got the material science figured out.
Likewise the biggest single boon to aircraft safety was World War 2. There they had many plane designs (any given plane might have many different configurations) and they learned all sorts of fun things. Like for example that you had to not route all the electrical system through a single junction box (A washer got loose and shorted out a plane during turbulence that then crashed in SF bay). Or how you need to run both the main and backup fuel pumps up to full pressure during takeoff because if the mains fail then there is not enough time to spin up the backups to speed before the engines lose power. Or how you have to make the fuel pumps big enough to dump the tanks fast for an emergency landing. All of those discovered by "accident".
Some may recall the crash in NY where the composite tail ripped off when the pilot whipped the rudder too and fro in a non-standard maneuver.
THe good news is that the military uses composites and so they have had enough accidents to work things out for the commerical jets.
Some drink at the fountain of knowledge. Others just gargle.
Which is exactly why we built our B2 Spirit stealth bomber out of it... or why Ferrari uses CF for their cars or why my high end Cannondale bicycle is made out of it. Aluminum doesn't bend; it just cracks given enough flexing (try this with a soda can). Any cyclist who knows bikes are aware of this.
EvilCON - Made Famous by
Remember Mr. Hincapie's spectacular http://www.cyclingnews.com/photos/2006/apr06/roubaix06/index.php?id=s002crash at paris-roubaix last year? That was his aluminum steerer tube that failed. I too am a cyclist and worked in the industry for a time. The carbon fiber the industry has been getting is not the same as the mil-spec/aircraft grade stuff. As others have pointed out, there are many, many factors that go into materials failure, such as fatigue life, tensile strength, etc. Layup, curing, process, etc. all factor into the "performance" of carbon fiber and its potential to fail. Aluminum fails. Carbon fiber fails. One is not inherently superior to the other. Each has their advantages and disadvantages. Comparing a cycling fork to an airframe in inappropriate. Comparing the standards between the two industries is inappropriate; a torque wrench is considered a "hi-tech" tool in a bike shop. As for "so many cyclists have died," I'm going to get out the broom and call shenanigans. Mr. Zinn has a little http://www.velonews.com/tech/report/articles/3270.0.htmlwrite-up on the issue and my guess is that he would've addressed the issue of "so many" deaths. Being fairly immersed in the community, I've never personally heard of cyclist dying from a carbon fork failure, although other failures (such as a flat tire) have led to some serious accidents. Considering that cf is used on the crowns of some mountain bike suspension forks, my guess is any issues with strength and durability would be found out pretty quickly.
I'm also a cyclist. I know lots of other cyclists, nearly everybody I know uses carbon fiber frames and forks, as I do myself. I've never heard of one failing in such a way that it killed the user. I mean, you do wear a helmet right?
I just tried googling carbon forks death, forks of death etc, and found absolutely nothing about people dying from catastrophic carbon fork failures.
And that doesn't even account for the fact that when an aluminum fork fails, it will be similarly catastrophic in terms of controlling the bike.
Today a new aircraft made from the miracle material called Unobtanium was tested today for the news media. In it's first flight test the plane was loaded with reporters from all the major news papers and electronic media.
The aircraft successfully took off and circled the airfield. Then to prove the strength of the new material, the plane dove straight into the ground from 30,000 feet.
Media representatives who were unable to make the maiden flight were stunned as ground crews dug the aircraft out of the earth and towed it back to the gate.
"My God!" cried out one of the most skeptical journalists. "The paint isn't even scratched! How could I have been so wrong?"
The president of the aircraft company stated that after the plane had been inspected and the remains of the passengers had been hosed out of the nose of the aircraft, flight testing would continue.
"We decided to do this test first and allowed our loudest critics to watch from inside the prototype. I am happy to say that the test was successful and the aircraft is undamaged."
"Atlas Shrugged" strikes again.
"Other than that, Mrs. Lincoln, how was the play?"
They're not the same necessarily
Boeing can only blame it on themselves. Not that long ago, Boeing supporters were putting out the story that Airbus airliners were unsafe because they used composite materials. Carbon fibre tailfins on Airbus airliners were singled out for special criticism (until Boeing also began to use them).
After decades of denouncing innovation as unsafe and unnecessary, Boeing's management has finally found it necessary in new technology. It is about time, but they should not moan to much if their old propaganda comes back to bite them.
On topic with blade out. Here are some blade out videos.
http://www.youtube.com/watch?v=wcALjMJbAvU
http://www.youtube.com/watch?v=mqRpsq7BosM
GE90 fan spool spins at around 2500 rpm with a fan of diameter around 135 inches. Do the math on the energy involved when a blade is released and the resulting instability of the remaining fan. Notice that the casing doesn't explode into pieces and send shrapnel everywhere. Always laugh at anyone that talks shit about composites.
It's not entirely true to say that the F-16 is made of CF. The aircraft is basically a straightforward aluminum design with a few structures made of composite. -The two ventral stabs (below the engine) are fiberglass/resin with aluminum honeycomb core. -The two horizontal stabs are CF/resin skins with aluminum W-ribs between the CF skins. The skins range in thickness from 3/8" at the attach point to less than 1/8" at the edges. -The vertical stab is designed in the same fashion as the horizontal stabs. The leading edge and rudder are made of different materials (Fiberglass/aluminum honeycomb core IIRC), so really just the center third of the stab is actually CF. -The nose radome is monolithic filament-wound fiberglass/resin, about 3/8" thick. All of these parts are VERY strong. I'm a structures guy in the USAF (I have a F-16c in the room right next to me while I'm typing this). I just repaired a horizontal stab today, but it was an auxilliary aluminum structure (one of the static eliminator bases). In my experience, the CF parts require the least amount of attention. The only problems that I've seen that could be attributed to the CF material itself would be fastener hole elongation caused by minor fluttering (which would be caused by CF's flexibility). This problem manifests itself as loose fasteners along the thin outer edges of the stab, as flexion of the part causes internal shear forces on the three structural members (two skins and the W-stiffeners). The fix is simple and takes about 90 seconds per fastener. I've never had to condemn a part due to delamination or outright catastrophic failure. Aluminum parts? I've tossed dozens due to corrosion, cracking, dents, scratches, deformation, etc. On the F-16, pretty much every aluminum part is fixed on a 'remove and replace' basis. Almost every part used complex milling and chem-milling processes that are impossible to replicate in the field. And no, cannot just weld up the cracks, for a variety of reasons. CF, on the other hand- one hot bonder and some supplies, and you can fix almost anything. I knew that someday /. would post a story about my area of expertise. 'Bout damned time.
-B
No offense, but I've stopped responding to AC's.
Fly a carbon composite drone through the wind vortex left by a jumbo jet. Aluminum planes break. Will the composite plane explode? Oh, and post the film to youtube so ppl will believe you.
Then file this 787 buzz into your drawer and smile about it.
-ac-
as parts of airliners for decades. Each new airliner has more carbon fiber parts. Boeing has accumulated a lot of experience with them. It's not like carbon fiber has never been tried before.
In that case, the question is would the leaking hydraulic fluid have affected an aluminum fin in the same or a similar way and led to said accident?
Cheers.
This is my sig. There are many like it, but this one is mine.
What studies show that CF is more susceptible to moisture degradation? Boeing is touting the CF airframe's resistance to moisture corrosion, saying the Dreamliner will have higher cabin humidity levels, thus providing a more comfortable passenger environment. (Apparently current recirculation systems remove a lot of H20 from the air to limit corrosion.)
And Greenpiss, er peace, and the rest of them hippies there...
Carbon fibre turbine blades failed spectacularly in the development of the RB211 engine http://en.wikipedia.org/wiki/Rolls-Royce_RB211 bankrupting Rolls Royce which eventually led to Bentley badges on Volkswagens.
We live in a world where terrorism is supposed to be the biggest threat to humankind. Especially in the country where the Dreamliner ist built they wage a so called "Global War on Terror (GWOT)". The money spent on this war and the additional money that went into security measures on the ground in relation to the lives lost or the potential lives lost to terror in the future is beyond any sane comparison.
For example: Even if you believe that there is only a very limited chance (lets say 10%) that global warming is in some part connected to the emision of greenhouse gases like methane or carbon dioxide the investment/benefit ratio in that area is so redicilously low compared to the fight against terror it is not even funny (especially, since this is a global issue and does not only effect Americans).
At this point I won't go into traffic safety, disease control (like developement and treatment in vaccines) or simply health care, because those are so much better researched that any comparison to terror in the investment/benefit ratio would be outrageous. I also don't want to go into the problems caused by limiting freedom in many ways (it does cost a lot of money to listen in on every telepone call).
And anyone here is surprised that shit like "carbon is unsafe, so we shouldn't fly Boeing" works in said country?
Bridges were first built from iron in the 1700s, fyi...
Aluminium WILL fail in a rather catastrophic manner at some point. Have a look at the 777 test video (http://tinyurl.com/2jyqb3). Because of the way the wings are constructed it isn't just a situation of bending it to a point where it won't bend back, eventually it shatters, in a rather impressive manner.
The carbon fibre break would doubtless be more impressive, however they can't make it happen. In the same test, the 787 wings didn't break. They aren't quite sure how much it would take to make them break but it would most certainly be enough to also break the testing rig, which is rather expensive. Given that they already survive more than 150% of the maximum load they are ever expected to see, which is more than their previous generation can take, I don't think it is a real concern.
Kenneth, what's the frequency?
I'm going to the casino. Don't gamble.
As he was known in Afghanistan when he wore that stupid outfit. I'm pleased to see this hasn't become a major issue for Boeing. I think from what we're seeing that the reality of carbon fiber and the general level of the discourse has improved actually. It's easy to talk about how stupid American's have become to believe people like Dan but the piece in Wired I think may signal a light at the end of the tunnel. Our elected leaders and the mainstream media have lost so much credibility at this point that intelligent, rational discourse may be making a comeback. I can hope.
What would Richard Feynman do, if he were here right now? He'd do some math and he'd follow through!
Richard Nixon wasn't impeached -- he resigned because he would have been impeached, and probably removed from office as a result. The only other president impeached is Bill Clinton, and the Senate decided by a vote that his actions did not merit removal from office.
No, he wasn't. But the House Judiciary Committee voted in favor of 9 articles on Saturday, July 27, 1974, 5 additional articles on Monday, July 29, 1974 and a Contempt of Congress citation, voted on Tuesday, July 30, 1974. His support in Congress had waned to the point that impeachment was a veritable certainty.
The Senate vote in Clinton's case was after a full trial, just as Andrew Johnson's was.
Nixon knew that, were a trial to occur in the Senate, he would be removed from office and would have no control over his removal.
Gods don't kill people, people with gods kill people.
I ought to know, I am one of these "experts" and I am a ruthless son of a bitch.
Yeah, sure you are. And you just happen to be willing to spill the whole sordid story as a sladot AC?
Grab a black helicopter, and meet me at the grassy knoll for lunch next tuesday. I'm dying to hear how you made Lee Harvey Oswald go berserk.
-jcr
The only title of honor that a tyrant can grant is "Enemy of the State."
n/c
...they forgot to thaw out the chicken first.
I'm more inclined to say that Danny Boy was more upset that Tom Brokaw was the one who was invited to emcee the initial rollout back in July.
This sig no verb.
I am posting anonymously for obvious reasons. I am bound under an NDA for this information.
In 2005, I was working at Smiths Aerospace, LLC (since purchased by GE) on the computer network for the Boeing 787. Smiths Aerospace had the contract for all the computer systems on the plane, which communicate over a doubly redundant ethernet-like network. Nothing is hard wired with cables - it's all fly by wire. My job was to develop and test some equipment to test the computer systems that would be connected to the network in the plane, and as such, I received regular status update emails about how various stages of network testing were progressing.
A few months prior to a large progress review by Boeing, progress reports started coming in stating that the network failed the design criteria for lightning strike testing - an unacceptable number of packets were dropped in simulated lightning strikes. The network ran entirely over copper. Every week, I got an email stating that the network was still failing testing, and that if they couldn't get it to pass, Boeing would insist that they move the entire network to fiber optics. Smiths Aerospace was being paid a fixed rate per system delivered, so the higher costs of a fiber optic network (both in materials and time to re-engineer) were very undesirable.
A week before the progress review, I got an email stating that the network had finally passed testing, so moving to fiber optic network equipment wouldn't be necessary. I looked a little closer, surprised at the sudden change. The engineers responsible had changed the test procedure to make the equipment pass the test, greatly reducing the voltages and frequencies the network was subjected to under the test.
Who knows how many other such shortcuts were taken, motivated by the bottom line. I quit my job shortly after that incident.
In a crash/burn situation I WANT a 'plane which automatically opens up to the outdoors. The last thing I want is to be trapped in a burning metal tube full of smoke.
No sig today...
Making sure the maintenance crews and the guys/gals who check a plane before giving the ok for takeoff around the world have a clue what to look for and how to report and maintain issues with this new material.
Great stuff only remain great if it's looked after properly by people who know what they are doing.
I think that after the "George W. Bush National Guard Letter", Dan Rather would have learned his lesson in bad journalism and disseminating bad information. .....And to think Dan Rather thinks that other people are to blame for the damge his reporting caused to his reputation.
Dan Rather's only problem is himself.
Knowing Google's lust for data collection, the Soviet Union is still alive and well inside the psyche of Sergey Brin....
You must be new here; citing actual source data is so not slashdot. You are, of course, right, but that own't help your karma any.
I love the arguments being thrown around on here.
First off, CF and composites have been used in aircraft construction for decades now, with quite a bit of success. Military, corporate, private, even homebuilt composite aircraft are all flying the skies as I type this, and aren't dropping like flies from shattering wings.
As several people have mentioned already, a properly designed carbon structure will be incredibly strong, and in the example of a wing, flexible to the point of failure (at which point it'll shatter). It's also been mentioned that the wings can likely touch on such a design, at least in theory, because of the strength of the wings themselves. Having seen demonstrations of CF wing strength, I believe it. But that's irrelevant. Let's consider the factors involved that would result in wings touching:
- To touch over the plane, there would have to be so much lift being generated that it pushed the wings that far. This is not likely to happen since the aircraft just won't fly that fast and air doesn't exert enough force given the other factors at play.
- To touch under the plane would be the negative-G mother dive of all time, again, not gonna happen.
- In either scenario the G-forces involved are astronomical, to be interpreted as "fatal before you even got close to it".
- In either scenario, the structures which keep the wings attached to the fuselage would fail long before that much force could be applied. In short the wings would come off quite likely very intact, if it were even possible to generate that kind of force on them (which it likely isn't).
I personally would feel very safe in one of these aircraft. I'm not a mechanical engineer, but I am a pilot. I've spent a lot of time learning what the design limits of the planes I fly are and why they are limited to that point, and knowing the amount of engineering that goes into something like a 787, I'm confident that those limits are not an issue. Does that mean it would be impossible to exceed them? No, any aircraft can be broken if twisted the right way. It just means that even a severely turbulent flight isn't going to take one of these down, unless the pilot is incredibly stupid - and you don't get to fly one of these unless you've demonstrated safe flying and general intelligence on the subject.
I didn't see Dan Rather's story, but I think he's an idiot for reporting it, and the people who assembled the story and did the fact checking likely should find a new job. Engineering an aircraft and flying one are both complex subjects that simply cannot be disseminated in the span of a few minutes on prime time TV. There is a reason that the critical stuff on a 787 was likely designed by people with "MS" and "PhD" after their name, and those designed components will be flown by people with "Sr. Captain" after theirs. I'd be more worried about problems at the assembly plant or a bad run of parts getting installed (which has been an issue plaguing manufacturers of every kind of vehicle known to man) than the engineering which said how those parts were to be built or used.
The problem with the Pinto was that in a rear-end collision, the gas tank, which was located behind the axle, could be pushed into the differential-housing bolts, causing the tank to rupture.
GP is most likely referring to "The Myth of the Ford Pinto Case," written in 1991 by Gary Schwartz, in which he pointed out that the fatality rates per million cars on the road was lower for Pintos as compared with a number of other comparable subcompact cars. It's an interesting read.
Ford is once again under scrutiny for putting gas tanks behind the axle, this time in the Crown Victoria (aka Police Interceptor.)
The original 1960-63 Corvair had a tendency to fishtail especially if the tires weren't properly inflated (and the "proper" tire inflations, , but (1) later Corvairs fixed that problem, and (2) a number of other cars of that era had a tendency to fishtail. From 1965 on, the Corvair had an excellent fully-independent rear suspension like the Corvette.
So could the original Corvair, the Pinto, and the Crown Victoria have been designed better? Sure. Were their designs worse than average? Maybe not. Will cars be designed better in the future as a result of all this attention that has been brought to design flaws? I hope so.
My truck is like a series of tubes.
Rather is just fear mongering the public. Carbon fiber monocoque construction is a lot harder (and more expensive) than aluminum semimonocoque to repair if damaged. However carbon fiber is a lot better at withstanding the variable loads placed upon them. The cool part about the dreamliner is that the wings are way more flexible than any wing ever. After way exceeding the FAA required torsion loads the engineers were pushing a little farther. They test this by bending both wings up and inward until the wings can no longer take the stress and break. Because the carbon fiber wing did so well they believe they could bend the wings so far as to touch the fuselage of the aircraft without compromising their structural integrity. This design will also make the A/C ultra smooth in turbulence. Rather should be fear mongering about cars. In the Navy/Marine Corps Aviation community, there are more fatalities from driving accidents than from aviation fatalities in training, operations, and combat.
Well, my Ford pickup has its gas tank behind the rear axle too. However, it's protected by a whopping heavy chunk of frame, which I suspect ain't there in passenger cars.
Presumably this is better'n the tank inside the cab behind the seat, like it used to be, but LIS I never heard of any problems with the old design either.
[I've been rear-ended by a passenger car. My first clue was the panicked face at my window. She crumpled her bumper; I wasn't aware I'd been hit and the truck took zero damage. Nice to have that mass differential on my side..)
I guess your real point is that even engineers can miss the obvious, and only discover it by OH SHIT. And they do usually learn from their mistakes.
IANAE, but from all the discussion above (some from the Boeing engineer) it seems like there's really no ideal material when it comes to lightness vs strength etc., but there are some pretty good compromises, especially in light of how Airworthyness Directives are enforced.
~REZ~ #43301. Who'd fake being me anyway?
Although it's been available in aftermarket parts for a while, it's now available in production cars as well... the current BMW M3 has a carbon-fiber roof. Sure, it's a $50k production car, but I expect the material will trickle down to more and more vehicles each year. It's strong and light, and we need strong, light materials to increase fuel-efficiency across the board.
My truck is like a series of tubes.
The Aloha Air incident is a good example of what age and corrosion can do to an aluminum airframe. Every material has its weaknesses. Besides that, many parts of existing "metal" commerial airliners have been replaced with composites.
Wow...Just, Wow...
The lack of understanding in not only Dan Rather but in this slashdot reporting of it is just appalling.
To say that "Composite materials are brittle" is like saying "metals are hard." There are just as many different types of composite materials as there are metals, actually a LOT more. And their properties are just as varied as the properties of metals. In order to understand how the frame will function under aircraft loads, you have to know the properties of that INDIVIDUAL composite material. And if anyone knows how to make an airplane, its Boeing. So quit being retarded and realize that this airplane is one of the most amazing things since sliced bread.
Like inhaling toxic smoke is going to be your big worry if the PLANE is ON FIRE.
Well, actually it is. Here's an example for you: In 1985 an Boeing 737 belonging Airtours
suffered an uncontained engine failure during the takeoff roll, which punctured a wing fuel tank
causing a fire. The aircraft stopped just off the runway, never having left the ground, but 55 of
the 137 people on board still died, 48 of them from smoke inhalation.
http://en.wikipedia.org/wiki/British_Airtours_Flight_28M
There's been a fair amount of progress towards removing potential sources of toxic fumes
from aircraft cabins in the last 20 years. However, I find it truly depressing every time I sit
though the "this is how to put on your life vest" part of the safety demonstration when what
I really want under my seat is a smoke hood. It's far more likely to save my life.
You're right about your pickup being safer than the Pinto despite having the gas tank in the same location... the Pinto's rear bumper was called "ornamental" at the time. And while the bumper on the Crown Victoria isn't wimpy, the problem there seems to stem from the fact that people seem to run into parked Crown Vics while doing 70 MPH - this goes with the territory of being a police vehicle. It's going to be parked next to the freeway some of the time, or sometimes even on the freeway, if there has been an accident and the Crown Vic is being used as a barrier to keep accident victims from getting run over. So for a normal rear-end collision where the crashee and the crasher are both going pretty fast, the Crown Vic wouldn't be that bad because the difference in speeds isn't that great, but the difference between parked and 70 MPH is a situation that (as far as I know) cars aren't tested for during the design process. Since the safety of the whole country's police officers and deputies is at stake, I think it would be reasonable for the Federal government to hand Ford some cash to design the next version for maximum rear-end-impact safety.
For some reason the Pinto issue and the carbon fiber airplane issue of the main thread reminds me of a documentary I once saw on the old British Lotus race cars. Apparently the head engineer at Lotus was so weight-conscious that if the car didn't fall apart as it crossed the finish line, he considered the components to have been made too heavy, and would lighten them before the next race. This policy cost them a few drivers, who got frustrated at the questionable reliability and safety of the cars it gave them. You can't get something for nothing, and the crash-resistant mass of your truck (and my truck, a Ford with one gas tank in front of the rear axle and one behind it) will eventually go the way of the dinosaurs as we run out of gas to push these beasts around. I'm pretty sure the vehicles of the future will be electric, and they'll be made out of something strong yet lightweight like carbon fiber. Hopefully we won't see any dangerous Lotus-like extremes from car manufacturers on the way from here to there.
My truck is like a series of tubes.
Good point AC - anecdotal data always trumps statistics.
"TV anchors are not real journalists."
Except Dan Rather was, as he predates the current crop of "journalists".
Which was the whole point.
And which, again, moots your "argument".
Anyone who thinks that aluminum is automatically better than composite fiber throughout the expected life of the airframe. would do well to remember Aloha Flight 243. That's the plane on which the cabin roof ripped off in 1988. The plane was older, of course -- but I thought that was Rather's point: that as CF ages, it will become failure-prone while aluminum wouldn't. Nothing is perfect. Heck, even I'm getting a little more failure-prone as I age.