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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."
Actually, Dan Rather is probably not making this up - he's more likely (mis)reporting some allegations made by a now sacked Boeing engineer, Vince Weldon. The Register has a write up based on what was said by the engineer and the rebuttals made by Boeing and the FAA.
UNIX? They're not even circumcised! Savages!
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?
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.
Engineers who want to hang people on meat hooks are the kind of engineers you can trust. Passionate - that's what that is.
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?
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.
If his 70 million dollar suit against CBS fails - he needs to stay in the public eye to pick up another job.
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?
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.
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.
The documents were not only forged, they were incompetently forged. Rather blew it, and whether he did so because he hated GWB, or just wanted to be Woodward and Bernstein so bad he could taste it, doesn't change his guilt.
-jcr
The only title of honor that a tyrant can grant is "Enemy of the State."
Actually, poisonous fumes are a prime killer in any fire, including aircraft fires. Cyanide gas, released from burning seat material, has been the agent of death in many cases.
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.
Rather didn't single-source this. He has confirmation from a number of other, currently-employed Boeing engineers of doubts about the composite materials. And if you look at the resume of his main source, it's impressive - the man was one of the top engineers at Boeing, and had done high-level work on NASA projects. Does that mean he's perfect? No engineer is. Does that mean his doubts should be considered seriously? Of course, especially when other engineers do agree about them.
... from 15 feet up.
There' also the very plain fact that Boeing is rushing this plane to market with far less testing than was used for recent generations of more conventional passenger jets. That gives Boeing every incentive not to listen to doubts. Boeing is betting that this can finally allow them to pull decisively ahead of Airbus, who has caused Boeing serious hurt over the last decade. Maybe it can, in the short run. Orders are coming in. But what happens if there's a spectacular crash or three? Will Boeing take the reputation hit that, say, Ford took about the Pinto? Maybe not. The public expects there to be no survivors from jetliner crashes. On the other hand, the sheer number of people these things will carry means the first such crash will be the most fatal - not counting people in buildings crashed into - ever. There will be weeks of international media scrutiny.
Boeing, we should be relieved to know, has tested the fuselage by dropping a section of it
"with their freedom lost all virtue lose" - Milton
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).
True, it's not about if Dan Rather made it up or not, it's about if he did proper investigative journalism to determine if the allegations have merit out side of a disgruntled employee trying to stir up some FUD.
Or maybe Dan's just gone of the deep end. Of course, should a jumbo jet fall from the sky and crash, I don't think it's going to matter it it's made of, it's going to be destroyed. Now, in situations such as crashes on the runway, that might has some merit.
Courage.
Cheers,
Fozzy
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.
any many many other things that are perfectly reliable
A couple of points here: 1) Rather did not do the investigative work on the Bush story that blew up in CBS's face. It was a producer and her staff, and he delivered it on the air. Turns out that they were defrauded, under circumstances that have yet to come out. He was basically railroaded, and I wish him well in his lawsuit against his old bosses. 2) It's been noted elsewhere that all of this alarming information will either be invalidated or confirmed during the certification process. Well, as the piece points out, there is a "revolving door" between Boeing and the FAA, meaning that key employees of the agency who "behave" will get lucrative jobs with the aircraft manufacturer. Chances of an honest assessment which runs counter to the interests of Boeing are practically zero. Happy flying, everyone!
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.
I take it you don't actually understand how the TV news business works. Rather was the anchor for the news, he wasn't the one doing all of the investigation, research and fact checking on the stories that appeared. There just aren't that many hours in the day. Which is why news outlets will have producers, copywriters, fact checkers and a whole support staff that handles huge portions of the news end of things.
When it comes to the news, there are these very strict deadlines, and if you miss a key deadline by 20 minutes to fact check, you may as well just wait for the next day. And yes that's a big deal with a huge story, it could be the difference between breaking a story and being a me too response.
Using hindsight as a measure of how well an investigation was done is a practice with its sole root in ignorance. One would just assume that Nixon would be outed for the plumbers.
I think that it is amazing that people are genuinely OK with the lack of hard reporting on any of the presidents activities or the huge number of changes of course which were justified as not being changes at all, but totally against an honest mistake.
If the press had been really on their job instead of pussy footing around all the potentially huge stories without investigating them, I seriously doubt that the W fans would be complaining about this one instance rather than how the "liberal media" is out to get an honest politician.
Of course, they also tested it in many other ways - the drop test is simply one of the many tests the FAA requires. They have even done testing not really required by the FAA - for example, they bent the wings back to see how strong they were until they touched over the cabin!
Most of the tests are on youtube, by the way!
while (sig==sig) sig=!sig;
The story is about a former Boeing engineer who has serious concerns with the new plane's safety.
Nope, it's about a guy who got canned for making racist remarks on the job, looking for some way to lash out at Boeing and get some revenge. Fuck him.
-jcr
The only title of honor that a tyrant can grant is "Enemy of the State."
BS - the FAA does not examine the plane and "decide" if it is airworthy.
The FAA has set some tests that must be completed by all aircraft manufacturers - and the tests have extremely simple, impossible to fake criteria. For example, the fully loaded plane must go at full throttle on the runway up to the no return line, and slam on the brakes. The plane must stop before the end of the runway, sit for 5 minutes (worst case overheating of the brakes), and then taxi to the terminal. The tires are expected to blow, and the brakes may catch on fire, but other than that no damage is allowed.
There are many tests like this. They have to pass them all. If you build a plane from glass and it passes these tests, it is just as safe as a solid steel one - it would just be a lot harder to design.
Materials do not give a plane safety. Engineering is what gives a plane safety.
while (sig==sig) sig=!sig;
You're referring to the stress testing of the wings, to examine at what percentage load factor they will fail at. And yes, they failed at, if I recall correctly, %150 of load capacity (something they will never see in actual flight without the rest of the airframe failing).
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?
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.
I thought it was still Gremlins ripping control cables out of the wings during flight... Luckily the inflatable auto-pilot (the kind with the inflation tube in it's lap) will still see you safely down.
Argh! can't keep all these movies straight!
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.
I assume you believe that the B2 bomber is neither large, nor pressurized, nor has it been in service for more than 20 years? And you are aware that despite being Northrop being the top level contractor, Boeing was the prime subcontractor responsible for the design and manufacturing of the composite fuselage and wing structure?
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.
Not quite... first, they haven't yet conducted a full-scale wing test; the airframe for that is still under construction. Second, the "touching over the cabin" was an exaggeration by someone at Boeing; the 787 wings are more flexible than traditional metal wings, but they aren't that flexible. And even if they could structurally bend that far, you'd rupture fuel and hydraulic lines and all kinds of other components long before reaching that point.
The meek may inherit the earth, but the strong shall take the stars.
Fired engineer: This plane is unsafe for the following reasons.
Boeing and government agencies: This plane is in complete compliance with FCC requirements, and this engineer is a racist.
Seems like it would be pretty premature to rush to some judgment on this issue without knowing:
1. The FAA's requirements for this new material, and their soundness.
2. Specific rebuttals of the claims, perhaps something more substantive than "it meets [unspecified] requirements" and vague, contextless mentions of future computer modeling.
I mean, fuck the guy if he's a racist prick. I doubt Boeing would allege something like that without a documented history, but I look forward to the release of the documentation when this goes to court. Still, I want to see some actual figures in response to his specific claims, and I don't understand why so many posters are in such a rush to judgmen...
Oh. Ah.
Tags != Comments, and -1 (Troll) != -1 (I Would Respond Angrily To This Poster So They Must Be Trolling)
Actually this is extra-insightful.
The resignation of Richard M. Nixon totally changed reporting and what reporters thought they could accomplish with an investigation. Prior to the 1970s administrations were considered inviolate even if they were poor. And that inviolability was created by the first President to be impeached, Andrew Johnson. Nixon was impeached based on information provided to the House Judiciary Committee and the Senate Select Committee on Presidential Campaign Activities by the press as well as leaks from the White House.
Now the press feels that it has a special relationship with government and can actually bring governments down. Rather was a reporter during the Nixon Administration and he (and all television networks) still has strong memories of being scooped by the Washington Post, regularly and routinely. Bring scooped is a painful experience to a reporter.
Mr. Rather certainly got so excited about the possibility of releasing information that could result in a change of government that he didn't closely examine what was provided him by the CBS producer who passed off forgeries as real documents. But, to give Rather his due, he had just come back from a long trip and didn't have much time. In retrospect, anyone younger than 30 could have figured out that a typewriter would not have made the kinds of characters (in a different type size) that were visible in the document that was used to show GWB's apparent absences from the National Guard. Problem is, big media companies tend to not hire people over 30 to produce.
Additionally, big media companies no longer hire people to do research and fact-checking like they used to back when Nixon was President. They don't hire these kinds of people because the role of television news has changed from "public service" to "entertainment." That happened when news divisions were told to actually make money for the broadcasters.
Perhaps Rather was still operating under an assumption that facts were being checked. He should not have assumed that. But certainly his executive producer ought to have been more "hands-on" with this particular report.
I don't think Rather "hates" Bush. I think he, like many broadcasters and reporters, trembles with the excitement at the thought of being a central figure in the change of an administration.
Gods don't kill people, people with gods kill people.
Certainly. A boat hull is subject to immersion in water 24 hours a day 7 days a week for 8-9 months. Many times for years if it bubbled rather than dry stored. In addition, you have cruising boats that have been in the water for decades.
Delamination of the layers, or "blistering" can be completely prevented by using an appropriate barrior coat of non-absorbing osmosis resistant epoxy.
The point is, engineers have decades of experience with laminates and epoxies that see far more moisture than a plane will in it's lifetime.
To address the next point, the poisonous chemicals during combustion are primarily a result of the expoxy that is used, not the fiber itself. Point in fact is that kevlar boats burn. It's not the kevlar doing the burning - it's the epoxy used in the lay up. Epoxy is just another polymer like the foam in the cushions, the plastic in the interior panels, or the polycarb used for lighting lenses.
A real problem with carbon fiber is fatigue. Each time carbon fiber panels are bent, the individual strands of carbon inside the laminate develop cracks. It is extremely difficult, indeed nearly impossible, to analyze what type effect these have on overall strength. This is why laminate structures using fiberglass, carbon fiber, and kevlar tend to catastrophically fail. One cannot see the tell-tale signs of impending failure like stress cracks. Once the fibers are no longer taking an appreciable amount of the load, the expoxy holding the whole thing to gether is just a hard piece of plastic that shatters.
However, the fatigue problem is one that is well understood. That is why the new military jets are using a large amount of laminates in their contrucstion. All in all, this report by a single engineer is a joke.
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
A380: 525 seats. Two levels. Frikkin' huge.
B787: 210-330 seats, depending on dash number. 767 replacement.
Boeing is not developing the 787 to compete with the A380. It is a smaller plane with a long, long range. Airbus bet that the industry wanted to focus more on hub-to-hub travel, and developed a plane that carries a whole lot of people from one major airport to another. Boeing took the opposite track, and bet that the industry wanted to focus more on point-to-point travel. This led them to develop a small plane with a long range that can go from minor airport to minor airport without a stop at a hub in between.
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You have several things confused.
... if it breaks too far beyond the design limit, it means you made it too heavy).
The 787 has not yet had wing tests conducted. The "touch over the cabin" part of your statement comes from the fact that many of the engineers at Boeing believe that to be possible; carbon fiber is so much more flexible than aluminum that it is, in theory, possible to bend the wings up over the fuselage until the two wingtips touch. Boeing will not perform the stress test to that extreme, however. Boeing will test the wings to the design maximum and then stop. They will not test to failure.
The reason for this is twofold: first, it doesn't matter after the design max. If the plane actually experienced design max stresses in flight, several other components (like the fuselage, or the vertical stabilizer) would fail first, so as long as the wing reaches that maximum without a problem, there's no need to test further. It doesn't matter how strong your wings are if your fuselage snaps in half first. Second, carbon fiber does not have a plastic strain region; it's all elastic strain before failure. That means that it will just continue to bend farther and farther without damage to the wing right up until failure (contrast with metal... when you bend far enough, it doesn't return to it's original shape anymore, but it has not yet failed). But, when it does finally fail, it doesn't snap, it shatters. That means clouds of hazardous carbon fiber dust and shards would be sent flying around in the factory. Not good.
The video on YouTube is of the 777 wing stress test conducted in the 90s. It was designed to reach 150% of max in-flight loading before snapping. It actually snapped at 154% (which is impressive
IAABE, but I don't work on the 787.
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The FAA has a number of Airworthiness Representatives (ARs) who work for Boeing and report directly to the FAA. Each of the ARs has a different area of specialization, and is in charge of signing off on the designs the engineers release to make sure they conform directly to the Federal Aviation Regulations (FARs). They also witness tests to ensure they are conducted properly, and work with the engineers to make good design decisions and ensure a safe aircraft.
These ARs report directly to the FAA (not Boeing), and they take their jobs very seriously. Their signature is right there on a piece of paper that says "safe to fly", and if there is a failure, their careers are essentially over. An engineer can only become an AR after completing an FAA training period and getting licensed by the FAA.
Once the plane has been built, the FAA collects all the signatures from all the ARs and all the completed test data that has been signed acceptable by the ARs, and when everyone involved is satisfied that the airplane was built in conformance with the FARs, the FAA "tickets" the plane, and certifies it for flight. (Some of those tests are conducted in isolation, like flammability tests of materials or electromagnetic interference tests; others are conducted after rollout, such as your brake test example, or avionics tests).
As a result of this rigorous signoff process, absolutely every single nut, bolt, and part on the airplane satisfies the FARs. Modification and repair shops have similar methods of ensuring compliance with the regulations.
In the case of the 787, the ARs would be signing off against Part 25 of the Federal Aviation Regulations, which governs large commercial passenger aircraft.
IAABE, but I don't work on the 787 program.
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Yeah, because if he is racist/personality challenged, he can't be any good in engineering either.
This isn't Shockley we're talking about, it's someone who was fired for cause, who didn't raise these issues before he was fired. If his former colleagues refuse to get on that plane, then I might give some credence to his claims, but until and unless that happens, I think he's full of shit.
-jcr
The only title of honor that a tyrant can grant is "Enemy of the State."
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."
There are two Rolls Royce Companies. The car company and the aerospace company. They split in 1973. The aerospace company is doing very well, thank you, and is the second largest (after GE) aircraft engine manufacturer in the world. Doing so well, that they bought the car company back from BMW.
The _labeling_ rights were sold separately to Volkswagen for their cars.
Hey, Mom! Is it beer, yet?