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."

Re:Typical Dan Rather

[Zocalo]

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 [theregister.co.uk] based on what was said by the engineer and the rebuttals made by Boeing and the FAA.

Trusting Dan Rather is like....

[Ancient_Hacker]

Trusting Dan Rather is like....

• 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.

Curing process

[Capt James McCarthy]

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?

unsafe, huh?

[Connie_Lingus]

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 [the-eggman.com].

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"?

Not as well studied?

[vogon jeltz]

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).

Re:Airbus have had problems with composite parts t

[Andy Dodd]

"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...

Re:TV reporters are idiots.

[ScentCone]

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

Yup. Michael Crichton's "Airframe" was actually a pretty good read on this very subject. Well, it INVOLVED this sort of subject. Most people also don't understand that the airframe ain't the same as the engines, and ain't the same as the particular airline's choice about all sorts of other things (from avionics packages, to training programs/frequency, etc). But it shouldn't just be infuriating to airlines, it should be infuriating to ANYONE who manufactures anything, works for someone who does, likes buying from anyone who does, has some of their Mom's 401k invested in someone who does, likes the fact that we get tax revenue from someone who does, who would rather buy from Boeing than ship the cash consortium manufacturer, and more.

I'm way more worried about the corrosion of national critical thinking skills and basic science education (which allows this sort of stuff to be written and passively consumed) than I am about the prospects of water-based corrosion to a CF airframe 20 years from now. We can fix/replace an airframe, but we can't fix some teenager that's been trained to not think, and who finds the trouble of actually grokking issues like this to be unfashionable and too much work. That Dan Rather is pandering to that cultural flaw (while suing CBS for $70 million for getting busted having done it before!) isn't just embarassing, it's Actually Evil(tm). And not just for Boeing's upper management bonuses.

so is the stealth bomber

[wardk]

any many many other things that are perfectly reliable

Re:Typical Dan Rather

[countyroad265]

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!

As a cyclist...

[blind biker]

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.

Re:Not as well studied?

[mapsjanhere]

I'm sure you do know sailplanes. And I'm sure that knowledge translates well to commercial airliners, since sailplanes are going through all those pressure cycles, are flown in every weather, are never hangared, and have a 30 year lifespan with 10,000 take-offs an landings. The virgin properties of carbon fiber composites are well understood. But damage tolerance and aging are a totally different thing. There is a reason why, at least in the US, the military still funds basic research and development on these things.

Misleading picture in the article....

[petaflop]

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 [wikipedia.org]. Careless journalism from WIRED too, perhaps?

FAA Certification of Composites

[Flyer434]

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.

Re:CF is anisotropic material

[Shotgun]

Your analysis is dead on, but I'd like to add just one point. The nature of aluminum corrosion, pitting, creates stress risers. That is a point where a crack starts easily. Build an airplane and you will soon understand that once a crack starts in aluminum it needs to be repaired or thrown away post-haste, for it will soon be two pieces of aluminum. Composites are somewhat more forgiving.

Re:Typical Dan Rather

[icebrain]

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.

Re:F-16 is made of composites

[King Louie]

As are the rotor blades on the CH-53E, the V-22, and many other modern helicopters. I've flown through the rain, hovered 5 feet above the water in a cloud of salt spray, and watched our aircraft sit on the ramp through days of rain at a time. And still the carbon fiber rotor blades didn't delaminate due to the water.

It doesn't take a lot of legwork to check out the more outlandish claims here.

Aluminum

[goombah99]

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.

Re:Typical Dan Rather

[Anonymous Coward]

IAABE also, and don't work on the 787, but I do work on their composite military aircraft. Using composites for aircraft is a non-issue as long as the following principles are adhered to: 1) the layers of composite are all there, sandwiched and bonded properly during production. 2) the aircraft is designed so that routine maintenance does not include operations that increase the risk of delamination. 3) regular NDI (non-destructive inspection) is performed via X-ray, ultrasonic or eddy current to prevent material failure. Boeing has made composite military aircraft for quite a long time that have flown well over the speed of sound, maneuvered at 9 Gs, and still been in good enough shape to fly for thousands of hours without serious structural maintenance. At subsonic speeds, the total allowable flight time for the 787 would be considerably longer than that. Dan Rather should be prohibited from flying in them when they are released.