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ANA and JAL Ground 787 fleets

ANA and JAL Ground 787 fleets

RE: ANA and JAL Ground 787 fleets

$hit happens. They will get it figured out. That is one intense complex airplane

RE: ANA and JAL Ground 787 fleets

Even the Wright brothers had their problems with a plane that was not much more than a glider with a small engine. The P51 - considered the world's greatest fighter had its share of problems - at first...

RE: ANA and JAL Ground 787 fleets

What are clearly random teething problems, in this case in a battery pack that Boeing doesn't make, are getting extraordinary press attention.



Mike Halloran
Pembroke Pines, FL, USA

RE: ANA and JAL Ground 787 fleets

(OP)
Random teething problems don't recur like this - they are random.

To me it seems like poor integration control of a vendor, likely compounded by ambiguous performance requirements, incorrect operating condition assumptions and schedule pressure.

RE: ANA and JAL Ground 787 fleets

Certain other aircraft had automatic jettison for runaway battery packs, I guess Boeing did not think that was needed here.
B.E.

RE: ANA and JAL Ground 787 fleets

From what I understand - this plane is mostly "electrical" Dumping a battery even if only slightly working might be a problem??

Not sure - don't know

RE: ANA and JAL Ground 787 fleets

...and from the BBC, "The US aviation regulator has told US airlines to temporarily ground Boeing's 787 Dreamliner, following a battery fault on one of the aircraft in Japan.

The Federal Aviation Administration (FAA) said that airlines must demonstrate that batteries are safe before flights can resume.

United Airlines is currently the only US airline operating the 787."

Dik

RE: ANA and JAL Ground 787 fleets

and the European Union has grounded them, too...

Dik

RE: ANA and JAL Ground 787 fleets

Some of the people on the Radio today shouldn't be allowed to breed.

Journalist for one of the big UK newspapers who said she was a nervous flyer and wouldn't be flying anymore because she was scared it was going to fall out the sky.

Even the "technical expert" they had on didn't actually tell anyone what has been going on. Just that these new planes rely on lithium-ion batteries like our phones and that they might explode.

RE: ANA and JAL Ground 787 fleets

yeah, europeans (eg flight international) tend to gloat over 787 problems
mind you Boeing did their share of gloating when A380 had it's troubles.

it'd be interesting to see if the battery over-heat protection had a wow switch inhibiting it ... "who'd charge these things on the ground ?"

mind you, i'd probably wait a few years before flying a '87 (so they get these teething problems out of the way) ...
A380 has matured just about enough to risk ...

RE: ANA and JAL Ground 787 fleets

Can't remember where I read it, but I did read that the battery containment system was designed so that in the case of a fire, nothing else would be damaged. They knew the risks with these batteries and took precautions. The grounding is a safety precaution.

This is all based off what I have read which was written by journalists with possible agendas, but still.

RE: ANA and JAL Ground 787 fleets

I hate to say how many mechanical problems have been experienced in older B-707, B-720, B-727, B-737 and B-747 acft: the rate for all early 7*7-100s was huge, but was not well publicized [1950s--1970s]. Now, every incident has thousands of instant observers/videographers and hundreds of unqualified journalists reporting every terrifying detail with gibberish commentary.

In the early 2000s I tangled with an Aero-News reporter on the V-22. He insisted it was dangerous widow maker. I pointed out similar/recent accidents/incidents with CH-47s, HH-53s, UH-60s, etc and got an "oh yeah"... may be it is on par with other new military helos" answer back. Now that the V-22 is maturing in service, it may never be an easy aircraft to maintain and fly... but will be generally safe and reliable for the military mission.

I seem to remember very serious developmental problems for Next-gen 737s [-500's and-on], early B-777s and all AB3xx's.

OH well, as someone once said: "never buy the "A" model of anything... especially if You are easily frightened/discouraged".

I heard another statistic [circa 1985]: 10% of all lear jets built [up to that time] had either been badly damaged or destroyed in accidents.

Regards, Wil Taylor

Trust - But Verify!

We believe to be true what we prefer to be true.

For those who believe, no proof is required; for those who cannot believe, no proof is possible.

RE: ANA and JAL Ground 787 fleets

from the BBC, "Boeing has suspended deliveries of its new 787 Dreamliner aircraft until a battery problem is resolved.

An email from the US aerospace giant said it would continue to build the plane, but not deliver any until US safety officials gave their backing.

The Federal Aviation Administration has joined the Dreamliner investigation."

RE: ANA and JAL Ground 787 fleets

(OP)
Boeing - Thales - GS Yusa - Securaplane.

English - French - Japanese - English.

No way anything could have gotten screwed up in the documentation in that chain.

RE: ANA and JAL Ground 787 fleets

People have short memories. There was a couple of years where it seemed as if DC10s were crashing left and right. At least, the battery problems don't appear to be fatal.

TTFN
FAQ731-376: Eng-Tips.com Forum Policies

RE: ANA and JAL Ground 787 fleets

The Lithium Ion Batteries are driving electronics replacing hydraulics, or so I've read. They found no overcharging recently, so it's not the charging system.

I'd guess motors with high peak starting current are driven by these batteries. It's difficult to perfectly spec and test conditions of motor peak currents, temp, altitude and win a contract needing where minimum weight for this battery is key. Hence my guess is these batteries pushed out too much spiky current and overheated due to altitude and cold wires (less resistance in wire) and less convection cooling and hence overheating. Just a guess mind you.

Technicians and Engineers who test the hardware at Boeing, Yuasa, etc are probably talking at coffee break saying things like "damn, it's probably that thing we saw....we told the management....they shouldn't have buried it....we got the contract though.....if we tell them we knew, we're screwed".

In my history I've been told to "Shut my damn mouth" about a software problem I mentioned to the customer and then thanked greatly two days later for "discovering that software problem so quickly at the customers ship CG-28 that we had time to fix it before they sailed". We all knew about the problem, we did nothing. Just like this problem I suspect.

RE: ANA and JAL Ground 787 fleets

(OP)

Quote:

They found no overcharging recently, so it's not the charging system.

No, there have been news reports that there was no over-voltage from the charging system.

Which in reality means that there was no over-voltage detected by the charging system - within whatever limits of resolution and sample speed exist within its self-diagnostic. If in fact it is even measuring the actual output, rather than just reporting what it thinks it's supposed to be providing.

But there are all sorts of ways to screw up a battery charger.

RE: ANA and JAL Ground 787 fleets

...from the BBC, "Airline safety inspectors have found no faults with the battery used on Boeing's 787 Dreamliner, Japan's transport ministry has said.

The battery was initially considered the likely source of problems on 787s owned by two Japanese airlines.

The world's entire fleet of 50 787s has been grounded while inspections are carried out.

Attention has now shifted to the electrical system that monitors battery voltage, charging and temperature."

Maybe the charging circuits... or how the batteries are used...

Dik

RE: ANA and JAL Ground 787 fleets

There would be lot of engineers, in a lot of different companies, doing a lot of overtime on this. Those of us who know little about it can only hope they will find the problem(s) without any remaining uncertainty.

RE: ANA and JAL Ground 787 fleets

...from the Winnipeg Free Press, "TOKYO - A probe into the overheating of a lithium ion battery in an All Nippon Airways Boeing 787 found it was improperly wired, Japan's Transport Ministry said Wednesday.

The Transport Safety Board said in a report that the battery of 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 APU from doing damage."

Dik

RE: ANA and JAL Ground 787 fleets

from http://www.wired.com/autopia/2013/02/airbus-ditche... hints dendrite growth, but doesn't sound conclusive if the whole thing burned an the word "appears" is used.

The news from Airbus comes roughly a month after the Federal Aviation Administration grounded Boeing’s new Dreamliners after two mishaps involving the planes’ lithium-ion batteries. Investigators continue to look into what caused a battery fire on-board a 787 parked in Boston, and a smoking, melted battery during a 787 flight in Japan.

The National Transportation Safety Board’s most recent update says it appears dendritic crystalline growth occurred in one of the eight battery cells inside the 63 pound lithium-ion batteries Boeing installed in the Dreamliners. The dendrites likely pierced the cellophane-like separator between the cathode and anode, leading to a short that caused the battery to catch fire. Dendrites are a common problem within the power packed lithium-ion batteries, Li-ion battery expert Dr. K.M. Abraham told Wired last week.

RE: ANA and JAL Ground 787 fleets

(OP)
If we elect to believe the media then there appear to be two independent problems.

Dendrites growing inside the batteries.

Miswiring external to the batteries.

RE: ANA and JAL Ground 787 fleets

(OP)
Everything I've ever done has been perfect the first time, so I wouldn't know. poke

RE: ANA and JAL Ground 787 fleets

Could the composite airframe have poor grounding circuits that result in additional loading on the ciruit, causing the batteries to overheat? This would be very difficult to correct, which would explain why Boeing would be interested in redesigning the battery for larger capacity rather than tearing the whole plane apart.

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