World's Largest Passenger Plane May Be Unsafe, Some Say 394
CNET reports (citing this BBC video account) that some aircraft engineers in Australia are concerned about small cracks that have appeared on the wing ribs of some Airbus A380 airplanes, a report says. They're calling for the whole fleet to be grounded, but Airbus says the cracks are harmless.
Harmless junk? Somehow I doubt it. (Score:0, Interesting)
I'm no aircraft engineer, but I do not feel comfortable with all this "pose absolutely no danger"-talk. AFAIK, particularly modern aircraft are engineered to trim down on weight as much as possible, and I would be VERY surprised if there were parts in the plane that could just safely break down posing no risk whatsoever. Such parts wouldn't be there in the first place, now would they?
just duct tape it (Score:4, Interesting)
Fun fact: that is actually legal in some cases [wikipedia.org]...
Unions winging over planes being serviced in Asia. (Score:2, Interesting)
This is just the unions posturing as part of their ongoing winging about Qantas doing more and more servicing of aircraft in Singapore and Malaysia. When a problem occurs in an aircraft which was actually serviced in Australia they are are strangely silent. At any other time they will winge and make loud noises to try and make it appear they are still relevant and try and somehow force all aircraft servicing to be brought back to Australia. This has been going on for years and stories on the nightly current affairs shows about it is a regular thing.
as an aerospace engineer (Score:3, Interesting)
I can say that composites are fucking weird... the cracks may have been accounted for in the design... kinda crappy but sometimes you are designed into a corner.
I don't have a picture of the cracks so i can't really make a good determination but if its composite and on the surface its pretty much harmless and if nessesary can be fixed with local resin cure.
The ones you got to worry about...
YOU CANNOT F***ING SEE BECAUSE THEY ARE BURIED IN THE STRUCTURE THATS WHY OLD SCHOOL ENGINEERS ARE SCARED TO HELL ABOUT COMPOSITES.
Re:Bad call by a union, nothing more (Score:5, Interesting)
Shhh.... Boeing does not do this....
http://abcnews.go.com/US/southwest-airlines-boeing-knew-737-flaw-expect-problem/story?id=13300089#.TwomuU8gifg [go.com]
"The aviation giant Boeing admitted today that it was aware of weaknesses in its 737 jets, but it never expected a 15-year-old Southwest Airlines jet to crack open in mid-flight. "
So why is this an issue with Airbus? One you said union, but I wonder if there is not some Boeing prodding going on here!!!
Re:just duct tape it (Score:5, Interesting)
Well, except speed tape isn't duct tape...so, -1 Misleading Subject.
Re:Harmless junk? Somehow I doubt it. (Score:5, Interesting)
And if those parts are designed to experience some cracking, as part of some carefully tuned tradeoff? There was some high altitude spy plane (maybe the Blackbird?) that leaked fuel on the ground, because when operating the temperatures would cause things to expand, so it was better to have it leak on the ground than break in the air. If a layman, or even an engineer unfamiliar with the project, saw that, they would naturally assume something was wrong.
Re:Harmless junk? Somehow I doubt it. (Score:5, Interesting)
There's just not enough info in the article to argue the case either way. OTOH I doubt there's ever been an aircraft without minor design defects that are fixed as they appear.
All commercial airliners have a log book in the cabin with a list of known broken/defective bits that the pilots are supposed to read before every takeoff and where they write down any weirdness they notice during the flight. None of the books are empty, even on brand new aircraft (ask a pilot...)
Re:Fucking ground this fleet. (Score:2, Interesting)
If, on the other hand, someone has valid concerns... then yes, safety takes priority.
Re:Fucking ground this fleet. (Score:5, Interesting)
The Ford "cover up memo" was in regards to post-crash fires after accidents involving rollovers, not anything specific to the Pinto and it's behind-the-rear-axle gas tank.
The Pinto got a bad rap -- it's actually got a better fatality record than similarly sized cars of the era.
Re:Harmless junk? Somehow I doubt it. (Score:5, Interesting)
I doubt there's ever been an aircraft without minor design defects that are fixed as they appear.
This is what happens when an airline is a launch customer (as are Qantas and Singapore I believe). When the airline is first in line to receive a new aircraft type, there are all kinds of bugs that the airline has to be willing to accept. For example, the first six production 787s [wikipedia.org] are overweight in comparison with what was promised. Similarly, I've heard time and time again not to buy the first model year of a new car or significant vehicle redesign because of potential problems that will be found only after production and then fixed in subsequent years.
Re:Harmless junk? Somehow I doubt it. (Score:4, Interesting)
Yes, it is the SR-71, which requires a generator or two to jump start, and a refueling in mid-air since it tends to lose a lot of fuel before getting off the ground.
Re:Earthquake anyone? (Score:5, Interesting)
Think about it, if the driverless cars that are definitely coming are proven to be safer than human driven cars, which I suspect they will be, how will any government justify letting us drive?
Even if the governemnt doesn't ban driving, the insurance industry will probably make it so expensive that it is effectively banned.
Re:If it ain't Boeing I ain't going (Score:2, Interesting)
Pilots don't need to be strong enough to move control systems by muscles alone. Hydraulics take care of that - whether fly-by-wire or not.
Yes but hydraulics systems have some negative aspects :
- you can't use one, you need a second one for backup and that takes weight and space.
- you have to design the airframe around the hydraulic system, its a constraint that simply doesn't exist on fly by wire airplanes which can have a more optimised airframe.
- from a reliability standpoint electric wires are better than a hydraulic system
Hydraulic system in modern airplanes is simply anachronistic. It makes no sense whatsoever.
Too Big To Fail (Score:1, Interesting)
Re:Fucking ground this fleet. (Score:3, Interesting)
It wasn't much of a secret
http://en.wikipedia.org/wiki/Aloha_Airlines_Flight_243 [wikipedia.org] [Wikipedia]
We had to cover this as part of Fracture mechanics when I was in school (along with the DeHaviland Comet)
Re:Fucking ground this fleet. (Score:4, Interesting)
Like it or not, there is, and must be, a price on human life.
Yep. Where most people get confused, is by conflating "value of MY life to ME" with "value of one citizen to society". They switch back and forth between these contexts in order to make whatever stupid "if it saves just one life" point they are working.
I think the best way to measure the value of a life to society is to look at per capita GDP.
For that matter, It is actually possible to determine the rational value people place on their lives. Of course you can't ask them directly, because you'll get gibberish... but you can ask it indirectly, by asking how much extra we'd have to pay them to take a job that has x% chance of fatality per annum.
The research has been done. They crunched the numbers and came out with $2-$10 million compensation for a job with 100% risk of fatality. The dollar amount somewhat depended on their current salary level. Interestingly, the dollar amount was pretty close to the average citizen's lifetime per capita GDP.
Re:pilot error as in hiding a bug in airbus autopi (Score:5, Interesting)
pilot error as in hiding a bug in airbus autopilot or it reading faulty gauges.
http://www.thedailybeast.com/articles/2011/05/27/air-france-flight-447-crash-report-airbus-autopilot-to-blame.html [thedailybeast.com]
The autopilot is not bugged. The autopilot wasn't even active for over four minutes before the crash. The headline is completely misleading, as the autopilot shut down as soon as conflicting airspeed readings came in. The system recognizes that it is unsafe to have a computer flying when the computer is getting faulty data. Thankfully Airbus flight computers are pretty good about error-checking, as they detected the airspeed discrepancy and acted on it - by turning control over to the crew and telling them why.
The accident appears to have been triggered by a number of events:
- Faulty pitot tubes providing faulty airspeed indications.
- Weather radar that saw a little storm ahead, but not the big, fuck-off storm behind it until the pilots decided to fly through the small storm.
- An avalanche of data coming into the cockpit during critical moments. During an emergency, it can be difficult to avoid focusing on a few bits of data, while others slip by.
The storm was recreated in an Airbus simulator for multiple flight crews. Using data the flight computer sent back to the maintenance crews during the flight, they were able to trigger the same errors (Pitot tube failure and airspeed mismatches).
Every crew survived.
Nice rant (Score:1, Interesting)
Except that other aircraft makers HAVE shown to do exactly what you describe. It is pretty common in fact for say Boeing to have been caught out to have tried to hide known issues that have caused deadly accidents rather then deal with the issue and save peoples lives.
When the economic incentive is big enough, human life looses all value. Look up on say Boeing doors being blown off due to known issues with the locking mechanism or indeed making the door open outward despite the obvious safety implecations vs the normal practice of opening inward.
Don't understand? Aircraft are pressured. if the door open inward the internal pressure presses it into the door frame making it near impossible to be blow out, try it yourself, kick in a door from the side it opens into, you are going to have to be pretty burly to get that done. But of course an inward opening door takes internal space you can't load cargo into that space so there is an economic incentive to have the door open outward so you can add a bit more cargo.
Boeing did it, the locking mechanism failed and people died. Multiple times and Boeing still hasn't fundementally fixed the problem by making the door open inward only. The economics of a few kilograms of extra cargo versus all the passengers on board.
Re:Fucking ground this fleet. (Score:3, Interesting)
While we're at it, we should ground the entire Boeing fleet as well...one of their roofs ripped off a couple of days ago during a flight and cracks have been found all over the 737 fleet.
http://abcnews.go.com/US/southwest-airlines-boeing-knew-737-flaw-expect-problem/story?id=13300089#.TwomuU8gifg [go.com]
Best part: They knew it could happen but they kept it a secret.
according to that article that was a 15 year old plane that was built after the 737's were redesigned in 2000...
Maybe they are reporting from the future?
Re:Small cracks (Score:5, Interesting)
Early 747's had similar issues with cracking on the spars in the nose. Some bits of aluminum even fell off a couple of planes (was that the primary buffer coupling?).
They were fixed as the planes cycled through rehab and the rib placement redesigned. 737's had a tendency to lose roof panels because of metal fatigue from improper riveting.
This sort of thing happens. You really need more info to determine if this particular case is serious.
Re:Fucking ground this fleet. (Score:5, Interesting)
That happened to my brother. The mechanic at the car dealer only put one nut on the wheel studs after replacing the brakes, and that one was on by only one turn. My brother was driving home in rush hour traffic when the wheel (left rear) came off, went bounding through the air, narrowly missed bouncing off two cars - one a cop car!, and fell off the road. My brother's truck came sliding to a sparking halt in the middle lane, blocking traffic for quite a while. No collisioins ensued, the cop never saw a thing. The car dealer repaired the truck of course - I think they had to replace the bed of the pickup.
Re:Small cracks (Score:5, Interesting)
That's a non-sequitur if there ever was one. Yeah, small cracks have a tendency to become larger under stress. So what. They always did, and they always do, and any plane that's flying out there has plenty of small cracks. This tells us nothing. What we need to know is what is the predicted rate of growth of those particular cracks under the stresses the material at the crack tip, in particular, is subject to. Add in tasty details about expected contributions of structure (will the cracks join like in Tu-144?), corrosion, etc.
Take a close look at the skin of the jet next time you fly. You may be surprised how many metal patches you will find -- patches that repair cracks or dings/dents.
Re:Bad call by a union, nothing more (Score:5, Interesting)
You are correct in the case of airplanes and other macro structures...
But, interestingly the little mirrors in your TI based DMD/DLP movie projector use aluminum hinges.
They bend ~1% strain @540Hz for ~20khr before failing and that's >10^10 cycles!
Why? because the hinges are thinner than a grain size and so dislocations don't propagate. :)
Cool