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Japanese Probe Finds Miswiring of Boeing 787 Battery

samzenpus posted about a year and a half ago | from the who's-to-blame dept.

Bug 201

NeverVotedBush writes in with the latest installment of the Dreamliner: Boeing 787 saga. "A probe into the overheating of a lithium ion battery in an All Nippon Airways Boeing 787 that made an emergency landing found it was improperly wired, Japan's Transport Ministry said Wednesday. The Transport Safety Board said in a report that the battery for the aircraft's auxiliary power unit was incorrectly connected to the main battery that overheated, although a protective valve would have prevented power from the auxiliary unit from causing damage. Flickering of the plane's tail and wing lights after it landed and the fact the main battery was switched off led the investigators to conclude there was an abnormal current traveling from the auxiliary power unit due to miswiring."

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Yay, time for finger pointing (2)

DavidRawling (864446) | about a year and a half ago | (#42961301)

Who will it be? Maintenance? Boeing?

Re:Yay, time for finger pointing (4, Insightful)

the eric conspiracy (20178) | about a year and a half ago | (#42961371)

Outsourcing contractor.

Re:Yay, time for finger pointing (4, Insightful)

Anonymous Coward | about a year and a half ago | (#42961463)

Themselves? [dilbert.com]

Re:Yay, time for finger pointing (4, Insightful)

ShanghaiBill (739463) | about a year ago | (#42962995)

A big chunk of the blame should go to whoever designed the connectors. For safety critical systems, it should be physically impossible to connect them in an unsafe configuration.

Re: Yay, time for finger pointing (0)

Anonymous Coward | about a year ago | (#42963091)

There aren't really any "connectors" in that sense. There are termination points, and how you connect your wiring is up to the engineer/electrician working on it.

Re:Yay, time for finger pointing (0)

Anonymous Coward | about a year and a half ago | (#42961389)

Nobodys of course. Nobody except that technician who can' t afford a truckload of lawyers.

Re:Yay, time for finger pointing (4, Insightful)

Anonymous Coward | about a year and a half ago | (#42961445)

Really? I am actually quite impressed. The degree of investigation over lighting failures and back up safety systems and all that is pretty awesome. Putting aside my condemnation of corporations like Boeing, this mess isn't damning, but rather assuring. Any finger pointing should be met with a reminder that the plane landed just fine. Granted, I'd be annoyed if my flight was grounded for this nonsense but degree of blame should reflect the problem caused.

Re:Yay, time for finger pointing (1, Insightful)

Anonymous Coward | about a year and a half ago | (#42961467)

I was just thinking that..the media will now have their blame game but at the end of the day it was a plane mishap that didn't include charred bodies strewn on the countryside. It was a glitch, that was easily fixed. I could have been much worse.

Re:Yay, time for finger pointing (4, Insightful)

bobbied (2522392) | about a year and a half ago | (#42961581)

I was just thinking that..the media will now have their blame game but at the end of the day it was a plane mishap that didn't include charred bodies strewn on the countryside. It was a glitch, that was easily fixed. I could have been much worse.

This whole idea of a wiring error sounds fishy and it seems to be based on flimsy evidence. These kind of things are proven by hard inspection of the aircraft, drawings, and designs not by observing flickering lights. Somebody in Japan wants these aircraft in the air really bad, and I'm betting they managed to talk Japan's version of the NTSB into this idea.

I'm waiting for the final report on this... Before I decide to get on one of these.. Because if this flimsy sounding reason is what I think it is, another plane is going to have a battery fire pretty soon and this time we might not be so lucky.

Re:Yay, time for finger pointing (1, Funny)

Anonymous Coward | about a year and a half ago | (#42961681)

Yes, never let a (albeit short) track record of no fatal crashes get in the way of an entertaining conspiracy theory.

Re:Yay, time for finger pointing (5, Informative)

ColdWetDog (752185) | about a year and a half ago | (#42961813)

You do realize that the flickering lights pointed investigators in a particular direction. THEN, after more analysis, they discerned the problem lay in miswiring. The flickering lights are not prima facie evidence of a wiring fault.

A bit more detail would be welcome. As it is, one cannot tell what happened or how many aircraft are affected.

Re:Yay, time for finger pointing (2, Interesting)

Anonymous Coward | about a year and a half ago | (#42962039)

You do realize that the flickering lights pointed investigators in a particular direction. THEN, after more analysis, they discerned the problem lay in miswiring. The flickering lights are not prima facie evidence of a wiring fault.

A bit more detail would be welcome. As it is, one cannot tell what happened or how many aircraft are affected.

the Japanese government is not big on providing details. the culture is one where you trust your elders, and the government is the ultimate parent. personally, I resent that.
*bows head to dodge trolls*

Re:Yay, time for finger pointing (1)

Redmancometh (2676319) | about a year ago | (#42963039)

Why did some jackass vote this down? It's just an obsrevationof how things work there. Both succinct and accurate...Most of us Americans have no idea what a "nanny state" really is.

Re:Yay, time for finger pointing (0)

Anonymous Coward | about a year ago | (#42963161)

No one voted it down, Red. AC posts have a starting score of 0 [slashdot.org] .

Re:Yay, time for finger pointing (1)

aaarrrgggh (9205) | about a year and a half ago | (#42962213)

Yeah... I'm pretty curious what kind of valves they have on the power system to prevent damage per the TFA.

Re:Yay, time for finger pointing (1)

Redmancometh (2676319) | about a year ago | (#42963055)

I thought valves just referred to semi-seals for fluids like gas or water.

The wiring was wrong (0)

Anonymous Coward | about a year and a half ago | (#42961949)

Pick on something, question it's validity and then suggest conspiracy... are you Elon Musk?

"The Transport Safety Board said in a report that the battery for the aircraft’s auxiliary power unit was incorrectly connected to the main battery that overheated"

The lights flickering is a secondary indicator, the primary indicator is the actual miswiring!

Re:Yay, time for finger pointing (3, Insightful)

Solandri (704621) | about a year and a half ago | (#42961991)

The 747 has something like 150 miles of wiring. The 787, which was specifically designed to reduce the amount of wiring, still has some 60 miles of wires. There's a lot of opportunity for miswiring something.

Re:Yay, time for finger pointing (4, Insightful)

buybuydandavis (644487) | about a year and a half ago | (#42962081)

The length of the wires isn't a useful metric - it's the complexity of the wiring that causes miswiring.

Re:Yay, time for finger pointing (3, Insightful)

Runaway1956 (1322357) | about a year and a half ago | (#42962163)

At a guess, I'd say the total length of wiring might be indicative of complexity. The machines that I have worked on that have only a few hundred feet of wiring are generally less complex than machines with thousands of feet of wiring in them.

For comparison, find an old Farmall or John Deere tractor, and compare the wiring to your modern automobile. An elementary school child can figure out the wiring on an 50 to 80 year old tractor. Good luck with your car - experience mechanics have problems chasing down problems, especially intermittent shorts.

Re:Yay, time for finger pointing (3, Insightful)

aaarrrgggh (9205) | about a year and a half ago | (#42962231)

Only if you assume the topology is the same. The 747 is likely to be much more of a "star" topology with traditional circuit breakers. The 787 is more of a "bus" topology with solid-state relays.

Re:Yay, time for finger pointing (3, Insightful)

viperidaenz (2515578) | about a year and a half ago | (#42962277)

Then compare a "modern" car with a very modern car. The huge mess of wires is being replaced by CAN and LIN buses.

Re:Yay, time for finger pointing (4, Funny)

athmanb (100367) | about a year and a half ago | (#42962401)

They originally planned to use 60 miles of wiring but then they only ordered 60 kilometers of wires so two thirds of the devices are not connected. It's not that big of a problem though since most things are covered by redundancy.

Re:Yay, time for finger pointing (0)

Anonymous Coward | about a year and a half ago | (#42962079)

the flickering lights triggered the hunch. deep investigation of the hunch uncovered the proof. I would tell you to RTFA, but this is easily inferred from the summary. mods should be banished from getting points...

Re:Yay, time for finger pointing (2)

sjames (1099) | about a year and a half ago | (#42961997)

That is important to keep in mind. Because of the things they did right, the thing they did wrong hasn't killed anyone.

Re:Yay, time for finger pointing (0)

Anonymous Coward | about a year and a half ago | (#42962217)

There needs to be zero tolerance for ANY failure of an aircraft. Especially on fly-by-wire system planes.

Falling out of the sky is not optional when something really goes wrong.

Re:Yay, time for finger pointing (3, Interesting)

bobbied (2522392) | about a year and a half ago | (#42961549)

Who will it be? Maintenance? Boeing?

All of the above!

I'm skeptical of this story. They are basically saying that somehow the wiring got messed up in such a way that everything still worked, but the battery was improperly charged/discharged by the APU. The evidence they have is some lights that flickered. This seems fishy to me.

If something is miswired, then it's going to be possible to PROVE that as fact. Even if the unit was cut from the aircraft, it would be possible to physically inspect and verify what wire went where. Flickering lights are NOT PROOF of anything being incorrectly wired.

If the drawings don't match the design, you can PROVE that by inspecting the drawings. If the aircraft doesn't match the drawings you can PROVE that by inspecting the aircraft. We have NO proof here.

I'm guessing that somebody in Japan wants to get these aircraft back into the air, bad enough to come up with some story with flimsy evidence and managed to get Japan's version of the NTSB to agree.

Re:Yay, time for finger pointing (2)

marcosdumay (620877) | about a year and a half ago | (#42961649)

Add to that that there were other, less severe but similar problems with the battery on other planes.

Also, I'd say (but nobody listens to me anyway) that if the battery can be misswired like that, it's a design flaw and Boeing should issue a correction. Of course, there is a lot of needed research before stablishing that the battery in fact has this problem, but that'd be the proper action.

Re:Yay, time for finger pointing (1)

icebike (68054) | about a year and a half ago | (#42961657)

I'm skeptical of this story. They are basically saying that somehow the wiring got messed up in such a way that everything still worked, but the battery was improperly charged/discharged by the APU. The evidence they have is some lights that flickered. This seems fishy to me.

I tend to agree. The summary and TFA are so confusing, its hard to figure where exactly the miss-wiring was. Was it in the APU, or the APU's seperate battery, or the Main Battery, or what? They simply say the APU Battery was "incorrectly connected". Does that mean it was never intended to be connected to the main battery, or was reverse wired, or shorted or operates as a different voltages, or what?

So far Boeing is mum on this particular report.
Instead they are proceeding with insulation between battery cells [nytimes.com] and cooling.

Boeing’s plan would be to redesign the batteries to place insulation inside and around each of the eight cells to minimize the risk that a short circuit or fire in one of thecells could spread to the others, as investigators have said occurred on the battery that caught fire in Boston on Jan. 7. Boeing might also adjust how tightly the batteries are packed.

So no clue what caused it but if we insulate the battery a little better maybe we can contain it? Seems almost as fishy as the article mentioned above.

Re:Yay, time for finger pointing (2)

plover (150551) | about a year ago | (#42963273)

They learned at least two things from this incident, not one. The first lesson is that it was "miswired" (agreed, a fishy statement), but it means they can test some wiring or insulation in existing and future planes to make people think they're doing enough to get the planes back in the air. Second, and more importantly, they learned that the batteries can burn as a group, and that they need to minimize the damage a battery fire can cause by better restricting the ability of the fire to spread. So the next time this happens, the plane won't be at as much risk.

Re:Yay, time for finger pointing (5, Insightful)

anubi (640541) | about a year and a half ago | (#42961831)

When I read of it, I felt more vindicated than surprised.

During my tenure in aerospace, I had witnessed more and more of a disregard for detail work. What used to be a good thing called "attention to detail" started being regarded negatively as "being a perfectionist".

The devil is in the details. Thousands of things work perfectly. One does not. This is the inevitable result of overlooking just one detail.

Re:Yay, time for finger pointing (4, Insightful)

router (28432) | about a year and a half ago | (#42962471)

I agree.

It shouldn't have been possible to "miswire" an aerospace battery, the connectors should have been coded, the wires, and the inspectors should have seen and tested this. Battery failure is still a process failure. Unfortunately, process failures are the most systemic failures possible. Lets hope I'm wrong....

andy

Re:Yay, time for finger pointing (2)

PolygamousRanchKid (1290638) | about a year and a half ago | (#42961825)

Boeing should have called the Call Center Help Line. The first question they always ask, is, "Is the device plugged in correctly?"

I find it mildly amusing that the Airbus A-800 also had problems with the wiring. They blamed that on a mismatch in CATIA system between French and German engineers.

It's amazing, all those high-tech doo-hickies, whatchits and gadgets in the plane. . . and in the end a wiring problem causes the system to fail. Maybe in the future, they can just all use one bus, and get rid of the wiring.

Re:Yay, time for finger pointing (4, Funny)

Runaway1956 (1322357) | about a year and a half ago | (#42962123)

It wasn't me! I swear it wasn't me! I've never worked on an aircraft in my life!

Sux2bthatguy!!

(Note that Runaway is color vision impaired, and has in fact wired things wrong from time to time.)

What? (0)

Anonymous Coward | about a year and a half ago | (#42961311)

Can't they make an idiot proof power plug?

Re:What? (4, Funny)

girlintraining (1395911) | about a year and a half ago | (#42961419)

Can't they make an idiot proof power plug?

Because idiots are much more resourceful than ordinary people.

Re:What? (3, Interesting)

Sponge Bath (413667) | about a year and a half ago | (#42961471)

Because idiots are much more resourceful than ordinary people.

Behold! [brynmawr.edu]

Re:What? (2)

c0lo (1497653) | about a year and a half ago | (#42962389)

The original [cantrip.org]

Re:What? (2, Insightful)

Areyoukiddingme (1289470) | about a year and a half ago | (#42961465)

Yes, but commercial airliners aren't built with plugs and sockets. For weight savings, everything is directly hardwired. At least, in pretty much every airliner prior to the 787, and I can't imagine Boeing changing that. Military aircraft are built with plug and socket connectors, but both sides of the connection are big bulky heavy metal components. When your plane is a cockpit and wings strapped onto a giant oversized turbine, you basically don't care about weight, but commercial airliners are the exact opposite. They're obsessed with weight savings, so the miswiring happened during initial assembly and their quality control procedures were too poor to catch it. Boeing has fallen a loong long way.

Someday, people are going to look back on the outsourcing mania of core competencies by MBAs over the past generation as sheerest idiocy.

Re:What? (4, Insightful)

hawguy (1600213) | about a year and a half ago | (#42961645)

Yes, but commercial airliners aren't built with plugs and sockets. For weight savings, everything is directly hardwired. At least, in pretty much every airliner prior to the 787, and I can't imagine Boeing changing that. Military aircraft are built with plug and socket connectors, but both sides of the connection are big bulky heavy metal components

Do you have a reference for that? It doesn't make sense that field replaceable parts are hardwired in - you'd have to clip the wires to take it out, and every time you clip the wire it gets shorter, so eventually you'd have to run a new wire back to the source.

Even for parts that aren't replaced often, it seems that hardwiring would just increase the chance of error - if everytime they replace an engine someone has to sit down and manually splice 200 separate wires, that seems a lot more trouble prone than plugging in a dozen connectors that were wired in at the factory and tested on the factory test harness to be sure every wire was connected to where it should be.

Re:What? (2, Informative)

Anonymous Coward | about a year and a half ago | (#42961789)

Slightly different, but my friend works for a company that makes in-flight video systems for planes including Lufthansa. While not mission critical, they still have to follow FAA and other regulations... one of which is some of the plugs they use plug in and then are secured in place with 12 to 16 screws even though the signals being passed are just network/video/audio.

I don't see why they couldn't use plugs of the same fashion instead of hard wiring everything

Re:What? (1)

colfer (619105) | about a year and a half ago | (#42962073)

I'd say in-flight video is mission critical, look at SwissAir 111. The company was so eager to cash in on midair gambling they overloaded the wiring with standalone power supplies rather than putting in a more sensible system. Crash. http://en.wikipedia.org/wiki/Swissair_Flight_111#TSB_findings [wikipedia.org]

Idiot (0)

Anonymous Coward | about a year and a half ago | (#42961801)

They are wired together with bolts and screws, often coded so you need the right tools,

FRUs are socketed, the inside hard wired

simple, MFG, omb

Re:What? (1)

rsclient (112577) | about a year ago | (#42962511)

Hmmm -- a quick bing search for "aviation grade connector" shows lots and lots of connectors. There are even magazine articles about them.

http://www.aviationtoday.com/av/issue/feature/Product-Focus-Connectors_18865.html [aviationtoday.com]

Re:What? (1)

Nefarious Wheel (628136) | about a year ago | (#42962723)

Posting to undo an egregiously stupid mod. #spamapology

Fucking idiot (1)

Anonymous Coward | about a year and a half ago | (#42961675)

What the fuck are you talking about? There are cannon plugs all over the place. The reason you think "directly hardwired" is because almost each LRU has its own circuit breaker. You must be one of the fucking PHBs

Re:What? (0)

Anonymous Coward | about a year and a half ago | (#42961735)

Today, people are looking back on the outsourcing mania of core competencies by MBAs over the past generation as sheerest idiocy.

FTFY. I think the only ones around the lazy B cheering about outsourcing at this point are the idiot MBAs.

Re:What? (1)

anubi (640541) | about a year and a half ago | (#42961933)

Those "idiot MBAs" landed a comfortable retirement plan.

The "perfectionist engineers" were laid off.

What used to be the crown jewels of the company, the core competencies, are now commoditized for lowest cost overseas manufacture.

Most of our core corporations have been reduced to a cadre of highly paid salesmen selling a branded product, of which one can purchase identical generic equivalents. The last vestige of holding onto power is by keeping the generics out of the market by legal maneuverings of copyright and patent law.

Re:What? (0)

Anonymous Coward | about a year and a half ago | (#42962241)

Those "idiot MBAs" landed a comfortable retirement plan. The "perfectionist engineers" were laid off.

Engineering and salesman are both skilled jobs. Engineering can be done easier overseas than selling to the US market. Selling to the US market requires a certain skill that can't be outsourced. So, the MBA is more valuable than an engineer.

Of course, the US is buying by racking up enormous debt and selling to America will hardly be the skill of the future.

What used to be the crown jewels of the company, the core competencies, are now commoditized for lowest cost overseas manufacture.

Well, the overseas engineers and salesman woke up from their deep slumber and started building their economy. A company needs to act in it's best interests and if you think protecting the crown jewels is what a company should be doing, that is the fast lane to stagnation and obsolescence. Companies constantly need to innovate, understand the market, find new avenues of income and take risks.

Most of our core corporations have been reduced to a cadre of highly paid salesmen selling a branded product, of which one can purchase identical generic equivalents. The last vestige of holding onto power is by keeping the generics out of the market by legal maneuverings of copyright and patent law.

One might argue that we are smarter, more innovative or better than them and there is some inherent exceptionalism to what we are. However, people anywhere in the world can achieve what we have if the social environment is right. The rest of the world lives on less but have the same number of hours in their lives and thus the labor will be cheaper overseas. Their skill levels might not be par to our top engineers but they do work for less. However, there is no inherent ceiling to overseas engineering skills and within a decade or two can "catch up".

Take the example of top guitar manufactures like Gibson and Fender. They decided to outsource some guitar making to Japan for the lower end models. Within the decade, they had to close that down because the craftmanship had improved so much in the Japanese factories that they were competing with the "Made in USA" lines. Next cheap stop was Korea and the same thing happened. The other cheap stop was Mexico and same thing happened. They have kept the "Made in USA" line intact my severely restricting the components and features that are allowed to be made in the outsourced countries (inferior electronics, less frets, less finishing etc).

While foreign engineering and talent is currently inferior, it will not remain so. It can as good as American talent and engineering in the near future.

Re:What? (1)

Brett Buck (811747) | about a year and a half ago | (#42961871)

What in the world are you talking about? Very few connections are hardwired, almost everything has a plug, usually, a rotary cam-lock plug from Cannon, etc.

        Do you think they solder all the avionics in place?

Re:What? (3)

garyebickford (222422) | about a year and a half ago | (#42962261)

AFAIK you are completely incorrect. Just using the 787 for example, the entire thing is built in modules including wiring and all, that are built and tested by subcontractors and then plugged and bolted together at the Boeing assembly plant. All commercial aircraft that I am aware of at least since the 1940s has had connectors. The biggest problem with connectors is not the weight but the unreliability. Each connector is a potential point of failure, so aircraft electrical connectors are actually heavier - they have positive scraping between the two parts of each connection, often have moisture resisting / sealing. and have a threaded ring that holds them together. Then (IIRC) there is an additional set of tabs through which a wire is threaded and itself positively bound - used to be twisted, now I think they use a mechanical crimp. The wire assures that the threaded ring can not unscrew itself due to vibrations.

The most expensive cost for a commercial aircraft after fuel is the cost of downtime - time spent fixing things costs thousands of dollars per hour. Therefore everything on an aircraft is designed to be removed and disconnected quickly, efficiently and safely - including things like wings, tail fins, etc. FAA is not going to allow the mechanics to cut wires and fasten them back together, so again the connectors are designed so that each one can only go one way.

Re:What? (2)

confused one (671304) | about a year and a half ago | (#42962281)

I'm sorry; but, you're wrong. Work for a sensor manufacturer that sells to the aerospace industry and I can tell you, commercial aircraft cabling is full of connectors. Same kind of locking connectors found on military aircraft.

Re:What? (1)

girlintraining (1395911) | about a year and a half ago | (#42962289)

Yes, but commercial airliners aren't built with plugs and sockets. For weight savings, everything is directly hardwired.

So they've managed to skim off maybe 10 pounds off the design of the aircraft, saving some several thousands in fuel costs over the operating life of the aircraft. A reasonable tradeoff considering the chance of the aircraft catching fire and then exploding when it hits the ground, killing everyone on board. *sips tea* Yeah. Makes sense to me. I mean, what's the cost of settling an accidental death claim for 300 people?

Here comes the math!

The cost of failure:
A product defect typically weighs in at $2.1 million USD per. So assuming 300 passengers and 10 crew, that's $651 million payout per plane going pop.

The cost savings:
Now, a 747 at least uses a gallon of fuel per second, or about 5 gallons per mile (average) on a flight. A typical domestic flight is about 2.5 hours in flight time, or 9,000 gallons of fuel. The weight of the aircraft, empty and unloaded, is about 95,000 pounds. It has 171 miles of wiring. Let's assume that we want to add connectors every 100 feet; That gives us 902,880 connectors. The average weight of a connector we'll say is 1.5 grams. that gives us 1,354,320 grams of extra weight to add connectors, or about 25,031 pounds.

So to add all those extra connectors would add an extra 26.3% cost to fuel. Now, the Dreamliner is slated to have a service life of about 30 years. We don't know how many pressurization cycles that equates to, but we can make an estimated guess. Let's just say 2 flights per day, 5 days a week. That'll be 1,560 flights before retirement then.

The average domestic flight is around 700 miles, we'll say. If the fuel cost before modification is 5 gallons per mile, at $3.30 per gallon... the cost of fuel per flight is $46,200. With the modification, it would cost $57,750.

Fuel cost over life of vehicle (before mod): 72,072,000.
Fuel cost over life of vehicle (after mod): 90,090,000.
Difference: $18,018,000.
Cost on failure: $651 million
Failure rate cutoff: 1 in 36

In other words, if a catastrophic failure that could have been prevented with electrical connectors happens more than 1 out of 36 planes, it's worth it. Otherwise, it's not.

Re:What? (0)

Anonymous Coward | about a year ago | (#42962823)

Yes, but commercial airliners aren't built with plugs and sockets. For weight savings, everything is directly hardwired.

Skinny guy who makes plugs for a living goes out of work, making savings for fat guys air ticket. Nothing new

Re:What? (1)

hairyfish (1653411) | about a year ago | (#42963145)

Someday, people are going to look back on the outsourcing mania of core competencies by MBAs over the past generation as sheerest idiocy.

I think my grandad said the same thing about transistors. You'll rue the day you ever gave up on valves he'd yell...

Re:What? (0)

Anonymous Coward | about a year ago | (#42963259)

erm....That's not how we (Airbus) build our stuff! Nearly everything has sockets, and how!
The older stuff has sockets with up to 100 connectors on them, the newer bus technologies are simplifying that, but not to the point of eliminating sockets.
It's vitally important for maintenance/Customisation etc, that we have the ability to quickly exchange any devices in the aircraft.
The errors normally happen in the plug/socket wiring process, as this normally occurs within the aircraft:
The cable trees are delivered ready made to the correct lengths etc, pulled through the cabin or wherever, and then the pulgs/sockets are fitted, and then the crosschecks are made.
What worries me in this finding is, if true, it indicates that the final wiring checks and not being carried out properly by Boeing, otherwise such errors should be found. I certainly hope that's not the case!

Links (0)

Anonymous Coward | about a year and a half ago | (#42961329)

http://en.wikipedia.org/wiki/Japan_Transport_Safety_Board [wikipedia.org]

http://www.mlit.go.jp/jtsb/english.html [mlit.go.jp]

Report is in Japanese, so feed the link to your favorite translator. Just now, Google returns "Sorry, we are unable to translate the page you requested." Which'd be fine if they didn't offer the "Translate this page" link, then take a while processing. Boneheads.
http://www.mlit.go.jp/jtsb/flash/JA804A_130116-130220.pdf [mlit.go.jp]

User error (5, Interesting)

girlintraining (1395911) | about a year and a half ago | (#42961361)

So basically, the user reached back behind the power supply while fiddling and bumped the 110/220V switch, and it caught fire. Naturally, they didn't say anything to the tech after setting the switch back besides, "It just caught fire! All by itself!"

The user in this case is a giant airline company, and tech support would be Boeing. The FAA, of course, is the QA manager, who reviewed the call, and after reading the ticket closure notes, facepalmed, leaned back into his chair, and took a deep draft of coffee.

Re:User error (2)

Cassini2 (956052) | about a year and a half ago | (#42961431)

Many power supplies are designed to autoswitch between 110V and 220V for just this reason. Cheap power supplies aren't.

I knew one customer that said: "We didn't know that it was a 220V machine when we connected it to 600V!" That bang was audible.

Re:User error (4, Interesting)

girlintraining (1395911) | about a year and a half ago | (#42961461)

No no, I know. I was just reframing the "black and nebulous art" of airplane maintenance into something easier to digest for slashdotters. It was either that, or a car analogy, and turning a plane into a car just felt wrong. :) The truth is a bit more complicated; But it still boils down to operator error and not a design flaw. Of course, a design that allows someone to plug in one component backwards and have the entire device go up in flames is not a good one, but it's not flawed in the strict sense of the word. It's disappointing that my $500 laptop has a feature that prevents the battery from being plugged in backwards, but a multi-million dollar state of the art aircraft does not.

Re:User error (1)

drinkypoo (153816) | about a year and a half ago | (#42961919)

You can't use a car analogy because the average slashdotter would cause the same kind of problem if they worked on their car. Auto shops are always seeing cars come in after they tell the customer about a problem with something fixed totally wrong, parts put on upside down and crap like that. Most people know jack diddly about cars. This, frankly, is a positive thing. I look forward to when they're all EVs and we can know even less about cars to keep them maintained.

In any case, this is basically an ideal demonstration of Murphy's law, not the popular conception thereof, but the actual meaning and history...

Re:User error (1)

garyebickford (222422) | about a year and a half ago | (#42962325)

Actually from my admittedly limited experience, FAA and airplane mfgrs are downright obsessive about making connections idiot proof and failsafe. It's pretty difficult to find places in an airplane where it's possible to plug the wrong things together or backwards. FAA has been dealing with Murphy for a very long time. In this case, if that's what happened, then it's one that slipped through the design and development process. FAA will mark this as a design failure and require Boeing to make it impossible to connect wrongly.

One thing I've learned from reading NTSB and FAA reports after aviation accidents (they usually come out about a year after the accident) - there is ALWAYS someone who gets pinned to the wall. There's always someone, sometimes multiple someones, who gets blamed. And then corrective actions are set out for all concerned.

Re:User error (0)

Anonymous Coward | about a year and a half ago | (#42962423)

FAA will mark this as a design failure and require Boeing to make it impossible to connect wrongly.

Or, way more simply, the connecter pins were soldered up wrong.

Re:User error (3, Informative)

number11 (129686) | about a year ago | (#42962701)

Actually from my admittedly limited experience, FAA and airplane mfgrs are downright obsessive about making connections idiot proof and failsafe. It's pretty difficult to find places in an airplane where it's possible to plug the wrong things together or backwards. FAA has been dealing with Murphy for a very long time. In this case, if that's what happened, then it's one that slipped through the design and development process. FAA will mark this as a design failure and require Boeing to make it impossible to connect wrongly.

Looking at that Japanese powerpoint [mlit.go.jp] , it looks like that may be exactly what happened. The battery cells are rectangular with a stud on each side of the top. Not even any prominent markings to indicate polarity, though the two studs seem to be mounted with different colored rivets. You'd think they'd at least have different diameter studs for the positive and negative, and jumpers with holes to match.

Re: the two studs seem to be mounted with differen (1)

girlinatrainingbra (2738457) | about a year ago | (#42963197)

Re: The battery cells are rectangular with a stud on each side of the top. Not even any prominent markings to indicate polarity, though the two studs seem to be mounted with different colored rivets.
.
The other possibility is that the installer was color blind and has been able to get by without that disability showing through. Most items that are color-marked often have a redundant marking that is not dependent on color vision perception (except for resistors and their color banding indicators, http://en.wikipedia.org/wiki/Electronic_color_code#Resistor_color-coding [wikipedia.org] and for cable runs of twisted-pairs that use paired coloring indicators [wikipedia.org]

Re:User error (1)

peragrin (659227) | about a year and a half ago | (#42961537)

actually at work we are dealing with that exact issue.customer returned an item that "stopped" working. After painfully trying to figure it out, we traced it to the power secondary power supply that converts 120 to 24v for the control systems. We replaced the PS tested the unit.

The customer had it for less than 20 minutes when they called up and said it wasn't working again. A quick check and the new power supply was toast.

They have a short in the box that supplies power to the unit in their shop dropping 240v into the machine at random.

Re:User error (1)

Obfuscant (592200) | about a year and a half ago | (#42961605)

They have a short in the box that supplies power to the unit in their shop dropping 240v into the machine at random.

Most modern, well designed power supplies can handle anything from 95V through 250V because that is what they could expect on their input depending on where in the world they are used.

That's because they are switching power supplies, and instead of using a simple transformer to create the right internal voltage that is then rectified and provided to the powered equipment, they switch the incoming current to maintain the right voltage on the output.

Now, I'd like to know where this "120/240V" stuff regarding the Dreamliner is coming from. TFA says nothing more than the summary about what was miswired. I'd suspect it wasn't a voltage issue when they say "a simple valve" would fix it (valve? Are they really using ancient tube-based circuits?). I'd suspect the problem is a current path that applies APU power to the batteries when it should not be. But, lacking any real description, it's a guess.

Re:User error (1)

Anonymous Coward | about a year and a half ago | (#42961713)

universal power supplies have more to do with the emergence of power factor correction. the old supplies with the 110/220 selector are switchers too - the selector switch controls the topology of the rectifiers that feed the ~300v input capacitors. on a pfc supply, that step is done by another switcher that draws current proportional to the instantaneous line voltage, and that switcher is made to handle the full 240v range anwyay.

Re:User error (1)

Obfuscant (592200) | about a year and a half ago | (#42961935)

the old supplies with the 110/220 selector are switchers too -

No, old power supplies with a switch are not switchers. The switches on old supplies actually changed the selection of the primary on the transformer. Most of them had two primary windings. Wired in parallel, they handled 240V. Wired in series, 120V. That produced the right output from the secondary so you'd not over-voltage the regulators or dissipate excessive power dropping too high a voltage. If you didn't care about the dissipation, you could have a linear supply that ran on 120 or 240 without caring, you'd just have to make sure you rated all the components to handle the higher voltage.

Newer supplies that are switchers may still have a switch, but it really shouldn't be necessary in a well designed supply.

Re:User error (1)

Nefarious Wheel (628136) | about a year ago | (#42962857)

SCREAM... PAF! (small mushroom cloud of oily capacitor smoke).

Maybe it was 120V after all...

Re:User error (1)

colfer (619105) | about a year and a half ago | (#42962107)

It was an analogy, bot really what is on the airplane.

Re:User error (1)

Nefarious Wheel (628136) | about a year ago | (#42962839)

Back somewhere in the late 60's-early 70's, there was a computer that came in for repair in the company I worked for - it was an SDS 930 (lovely old discrete-transistor machine). Someone had plugged a "MagPack" (an early cartridge tape drive) into the wrong slot on the bus, and the connector that was supposed to go there, into the MagPack's bus. The connectors were the same, but the circuits weren't. The circuit plugged into the MagPack's slot got a good healthy dose of one phase of a 440v power supply into a circuit that was expecting 0.5VDC. You could tell the logic state of the machine at that moment by following the carbon trails. Flipps were permanently flipped, flopps were permanently flopped. It looked like lightning had struck the frame.

Connector standards, even for simple antiques like RS-232 were a revelation, and were a service to us all. Gotta remember that engineering practices didn't just appear, they evolved. I respect connectors, especially after diving into their construction in a bit of detail. Properly designed, any good standard wiring loom connector will give you very little grief.

Japanese Probe (0)

Anonymous Coward | about a year and a half ago | (#42961485)

I haven't seen enough hentai to know where this is going...

Happened before (4, Funny)

Grayhand (2610049) | about a year and a half ago | (#42961519)

It's the damned metric +/- that causes all the confusion.

Re:Happened before (1)

deniable (76198) | about a year and a half ago | (#42961715)

They had a problem converting to Volts.

Re:Happened before (0)

Anonymous Coward | about a year ago | (#42962615)

It's the damned metric +/- that causes all the confusion.

absolutely !

sign the demand at Move On. org to switch to the metric system !

I'm calling BS here. The sys would have been run on battery for months before they flew these.

The drain would have been even higher without the engines firing, and the recharging load would have been much higher than the inverter load too...

This is a feel good explanation, and they are trying to make the japanese take the hari-kari, when it is obvious that a miswiring at the battery would have turned up at the battery inverter outputs WAY before a failure would happen at 50 % load.

Not seeing any of those commercials about the GE jet engines on these anymore either , are you?

This is/was a fail by the electrical engineers, and no one wants a bite of the sandwich, so they are making sushi out of it.

A protective valve? (2, Informative)

dgharmon (2564621) | about a year and a half ago | (#42961557)

"the battery for the aircraft's auxiliary power unit was incorrectly connected to the main battery that overheated, although a protective valve would have prevented power from the auxiliary unit from causing damage"

What is a power diode [slashdot.org]

Re:A protective valve? (1)

viperidaenz (2515578) | about a year and a half ago | (#42961621)

Perhaps they're using the term "valve" as a generic term to describe the behaviour, not the components used to implement it.
I wouldn't be surprised if they use transistors instead of diodes, to avoid the inherent voltage drop and subsequent power dissipation.

Re:A protective valve? (4, Informative)

the eric conspiracy (20178) | about a year and a half ago | (#42961733)

"Valve" is a generic term, slightly archaic for an electronic switch. Some vacuum tubes are called valves.

http://en.wikipedia.org/wiki/Vacuum_tube [wikipedia.org]

Since a transistor is simply a crystal triode, the terminology is reasonable.

http://www.beatriceco.com/bti/porticus/bell/belllabs_transistor.html [beatriceco.com]

Re:A protective valve? (2)

PPH (736903) | about a year and a half ago | (#42961943)

That might be a translation of the Japanese term. By a non-technical translator.

Re:A protective valve? (1)

confused one (671304) | about a year and a half ago | (#42962305)

They were called vacuum tubes in the U.S. and valves in the rest of the English speaking world. British translator perhaps?

Re:A protective valve? (1)

MichaelSmith (789609) | about a year and a half ago | (#42962435)

I think it means circuit breaker.

Re:A protective valve? (0)

Anonymous Coward | about a year ago | (#42963087)

its reverse current protection (in the most simple form a diode), breakers only protect from overloads

Japanese spin (1)

Anonymous Coward | about a year and a half ago | (#42961629)

The Japanese are doing everything they can to point blame away from Yuasa. As someone above noted, and, yes I did read the fine article, they have concluded that it must have been wired incorrectly after seeing some lights flicker and a white dove flying in the southern quadrant.

Re:Japanese spin (1)

anubi (640541) | about a year and a half ago | (#42962233)

If the battery management board was doing its job right, it would not have made any difference if they had miswired it that way. That is what "smart battery" technology is all about.

Smart battery technology enables the controller to look at every cell individually. No two cells are identical. They will leak charge at different rates. And won't have identical capacity. Especially over time.

A "smart battery controller" keeps track of the state of charge of each cell of the battery pack and allocates charging energy accordingly, likewise it supervises the rate of charge and allowable rates of discharge, including shutting down battery discharge as any cell approached its low charge level limit.

A miswire to the pack should not make it catch fire; however the miswire may well lead to unexpected behaviour, such as the battery "going dead" unexpectedly or failing to charge properly. In my expectations, a properly designed battery management device will have the capability of blowing open a fuse if necessary to completely disable the battery in the event of a severe failure or miswire - especially in the case of lithium chemistries which are intolerant of abuse.

I highly respect lithium cells for their performance, but also am highly aware of their response to being mistreated. They are very intolerant of being either overcharged or overdischarged. These things must be supervised.

Re:Japanese spin (1)

jet_silver (27654) | about a year and a half ago | (#42962481)

It may be you're right but the requirements might have led Yuasa to believe the battery management would be taken on by other system elements. Requirements writing is not all that easy, especially when you're trying to anticipate problems in equipment no one has had to rely on to such an extent before.

Damn fine work by the Japanese MoT nonetheless, aggregating clues from all over the place.

E4? (-1)

Anonymous Coward | about a year and a half ago | (#42961637)

new faces and many asshole to others Baby take my Too many rules and Rig4t now. I tried, juugernaut either are allowed to play And she ran

whistleblowers (1)

Anonymous Coward | about a year and a half ago | (#42961695)

It's gonna be fun to watch. Whistleblowers are starting to emerge telling of how safety issues were swept under the rug in the name of getting an already late project out, and engineering concerns were ignored or overridden by managers. It's very similar to the story of the O-rings on the Space Shuttle, where engineers knew there were problems, but their concerns were ignored.

Gonna be a real show over the next year as these people start coming out in greater numbers.

Japanese Probe? (4, Funny)

Charliemopps (1157495) | about a year and a half ago | (#42961777)

When you say "Japanese Probe" I had an entirely different idea in my head regarding what this story was about.

Re:Japanese Probe? (2)

MyHair (589485) | about a year and a half ago | (#42961849)

When you say "Japanese Probe" I had an entirely different idea in my head regarding what this story was about.

Weren't you surprised nothing was pixelated?

Re:Japanese Probe? (1)

viperidaenz (2515578) | about a year and a half ago | (#42962351)

I'm still waiting for the tentacles.

Re:Japanese Probe? (1)

mdielmann (514750) | about a year ago | (#42962533)

When you say "Japanese Probe" I had an entirely different idea in my head regarding what this story was about.

Miswiring sounds like it would be just as dangerous, either way.

Re:Japanese Probe? (1)

tool462 (677306) | about a year ago | (#42962569)

Tentacle porn is a reasonably good approximation of the 787s wiring diagram. And in both, bad things happen when the wires go in the wrong hole.

Stand by for SPEEA (0)

Anonymous Coward | about a year and a half ago | (#42961967)

The technical workers authorized a strike. Just watch Boeing goad them into it for a few weeks. They have a clause in their sales contracts relieving them of late delivery penalties due to circumstances beyond their control. Like strikes.

The contract will magically be settled after the engineers design a fix and its ready for manufacturing.

OK Now we are even (1, Funny)

Camel Pilot (78781) | about a year and a half ago | (#42962135)

For the Prius accelerator screwup....

Re:OK Now we are even (1)

Anonymous Coward | about a year ago | (#42963009)

The Prius screwup was proved a hoax. Everyone involved were liars.

If one plane was miswired, what about others? (1)

Streetlight (1102081) | about a year ago | (#42962891)

Presumably the same person who miswired the Japanese 787 miswired at least one other plane. That should be easy to check. If there are other planes with smoking batteries, check the wiring, then do it for all other 787s.

Japan is such a pussy nation (-1)

Anonymous Coward | about a year ago | (#42962927)

STILL have not avenged the 2 nuclear bombs in 1945.
Shame on you lotten americans! LOL

Apparently not the cause of battery fire (1)

Anonymous Coward | about a year ago | (#42962931)

Nikkei is reporting that this miswiring, which connected the auxiliary and main batteries by mistake, is due to a bug in an older version of the 787's electrical design. The bug was found and fixed in November 2011, but somehow Boeing never got around to re-wiring this particular aircraft according to the new plan. Nikkei also reports that the miswiring probably did not cause the battery fire, because there is some sort of an "anti-reverse current mechanism" in place to prevent damage even if the auxiliary had started to feed current into the main battery.

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