Japanese Probe Finds Miswiring of Boeing 787 Battery

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."

Comments

User error

[girlintraining]

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

[girlintraining]

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:What?

[Sponge Bath]

Because idiots are much more resourceful than ordinary people.

Behold!

Re:Yay, time for finger pointing

[bobbied]

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

[Anonymous Coward]

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*