New York Times article:

http://www.nytimes.com/2013/01/18/bu...boeing.html?hp

with this opinion:

ETOPS?
 

I'm familiar with the FAA AD process and have read the AD.

Suppose there is a re-design or different parts that the FAA deem to correct the AD condition and allowing the aircraft to fly again. What happens to the ETOPS certification? Is extra proving needed before ETOPs (at the intended level) is re-established?

Too much "Electrickery" methinks - should have stuck with a box of double A's !:ok:

mathewsjl...

This from Machinbird...

"As a betting man, I'll bet that the issue with the battery is actually with the charging system and insufficient feedback from the battery to the charging system regarding cell temperature. The charging system should not continue to charge a battery that is moving in the direction of thermal runaway."

I have read the special consideration re: LithIon issued to the 787 program by FAA. Other than failing almost all of them, utterly, in the emergencies, I did not notice a restriction in re: charging of a discharged system, LiIon.

This would be the salient issue, no?

The 787 is a very fresh and different approach to power/energy systems in commercial widebody. It is truly an electric jet.

More than ten years ago, I was involved in fireproofing a security system. The solution was weighty, but performed to spec. Lightweight ceramic and even lightweight concrete (sic) have been available for decades. The photo of the burnt and uncontained contents of the APU battery show a unit that has performed well, except at the top. It is difficult to imagine that a solution for the safe retention of the utility of such a high performing system cannot be supplied.

What is disconcerting is the thin limits that are exposed relative to weight saving in the E/E Bay. The a/c itself is amazing in its approach to efficiencies. A little cautious application of insulation and monitoring might (might) have saved the issue from reaching the state it did....

The electrical system itself cannot be re-engineered, without different engines and miles of 'plumbing'....

Highly reliable electric energy supply
 

Lemain:

:ok:

...micro APUs running, say, on ethanol. I don't mean run the existing APUs off ethanol, but replace the APU's service battery by a fuel cell or baby motor. It's all interesting from a technical pov and speculation, but the time needed to incorporate the technology into a civilian airliner is ten years.

I use a baby motor of 24 VDC 300W, motor generator in a motor home and in an electrical bike.

The time to incorporate it (Av) can be much less.

Important moment.

Rgds,

LiIon in the skies (and in the space)
 

archae86:

Good luck to them.

They will need...:}

ISS will be "upgraded" by same japanese supplier

:E

Good news
 

No I think he meant what he said which was that the design REQUIRED these batteries.

When the electrical system had been designed (requiring something like 1 MW of power!) the high energy density provided by use of Li-Ion technology was the only system which could provide such power at a reasonable size and weight.

A fait accompli in other words!

That is why this is not as simple a fix as some are trying to portray it. If the system can't be operated safely then either the batteries and charging system will need replacing for something a lot heavier and safer, or the electrical requirements of the model will need reducing. Either of those options is a headache and will take time. Ironically what they can take comfort from is that Airbus are running a similar system (albeit on a smaller scale) which seems to be stable.

As I said on the other thread, the best that Boeing can hope for is that this turns out to be a couple of dud cells in the two batteries which slipped passed quality control at Yuasa. ;-)

But does the A350 have the reliance on electric generation that the 787 Has?

SOS

FLOAT? Can these batteries be safely charged whilst under load? They are supreme conductors, I have always used them in tandem, never charging one when also discharging it. In fact, the system was designed to isolate the battery being charged, its hookup prevented dual mode.

Don´t blame the battery only. Also the surrounding circuits, charging management and software must be rechecked. And here we have the first sign, that it might not be the battery itself causing the failure. Seems that the battery was forced due to high voltage of the plane: Japan probe suspects excess voltage in 787 battery | Business & Technology | The Seattle Times

Think this is good news, revalidate a fuzzy battery concept needs years. To fix the surrounding power architecture seems to have faster options. :ouch:

Important information
 

Taunusflyer:

Quote:

---

Think this is good news,

---

If confirmed probably will lead to the less damaging scenario to Boeing.

787 required these batteries
 

DaveReidUK:

Quote:

---

Strange statement.

---

Probably the 787 design team decided for this batteries for some reasons like:

Aircraft requirements (weight, etc.) related to design optimization

High capacity per weight and volume

Integrated (internal and external) circuitry

Advanced design (promising better performance)

If the information on over voltage (from charger) is correct we may expect a faster solution of the crisis.

Dannyboy39 quoting Rananim

The difference is that Airbus started out with multiple suppliers many, many moons ago as a key part of their strategy. For Boeing this is all new territory and they are learning the hard way. Doubtless they will fix it and no one has died.

ALT ACQ pointed very sensibly that today's instant reporting and demand for ANYTHING to be said on the rolling news channel, just so that the channel can look like's up to date - is punishing countless companies and individuals all around the world and not just in aviation.

In order to certificate the 787, Boeing had to prove compliance with all the Special Conditions for L/I batteries listed at#111. Doing so took years. Service incidents now show that the aircraft does NOT comply. FAA is not going to be so gullible from now on, so recertification is going to take a v.long time.

The benefits of hindsight are amazing.

For instance you can't now argue that Boeing should have given the batteries an extra 100kg weight allowance because that would make very little performance difference for the simple reason that if you did that you'd have to allow every other manufactured component some extra weight as well - calls for heavier batteries are able to be made now because you have strong reasons to suspect a different but heavier battery type wouldn't have led to this issue.

Similarly with outsourcing. It is done all the time, presuming that proper quality accreditation was put in place for suppliers then it is standard commercial practice. If Boeing had to do everything in house they would probably be bankrupt due to all the extra staff they would have had to employ (on USA rates and conditions etc) and capital equipment spent on manufacturing machinery and other capital heavy startup items which would be more costly than having that load spread around the industry. You could argue they should have batteries in house, but only with hindsight.

And so it goes on.

The 787 will be a cracker airplane, no question about that. It's just a matter of being honest about issues and fixing them.

"Can these batteries be safely charged whilst under load?"

A battery cannot be charged and discharged at the same time. It is either charging or discharging. Current out (discharge or load) minus current in (charge) = total current. Which ever is the highest wins. I think the question is: can the charging circuit operate at the same time as the battery is discharging. Sorry for the trivial interuption.

If a battery can't be both charged and discharged, how can both my laptop and phone be on and under load when plugged in to charge and the battery still gets charged while the system is running?

Try googling "Kirchoffs Current Law" This is the basic theory.

Good grief, Li-Ion is almost ancient tech. Teething problems, yes. Sony built 10,000,000 batteries for computers that were recalled 5 years ago. Melted computers were all over the news (Sony supplied to makers like Dell in addition to their own). I wouldn't be typing on this iPad if not for Li-Ion, nor my 3 laptops nor 2 iPhones nor 4 cameras nor 2 drills. So it is not something new and untested. Do we blame the problem on Thales since they are he supplier and since they supplied the pitot tube on AF447 they can't be trusted? Is it a French conspiracy to take down Boeing? Since it was a Japanese subcontractor supplying to Thales that built the battery are they getting back for WWII and the a-bomb? Or is it that we engineers putting together our failure mode and effects analysis had an "I can't believe we missed that!" Moment? We engineers, being all too human, screw up. It's always been a fact of life - people do stupid things. Analyze, learn, resolve, implement, verify, and go on thankful nobody lost their life. Sometimes we are lucky - the engine explosion virtually destroying the A380 wing ended without loss of life by a miracle. Maybe the ANA pilot Thursday performed a similar miracle. Pilots saving our engineering asses. Thank you very much!

Using the laptop, mobile, etc. whilst charging the battery
 

Peter643 and Cool Guys:

Simple:

1) The external supply has a greater voltage than the battery.

2) The battery receives some of the current from the external supply.

3) The load (laptop, mobile, etc.) receives some of the current from the external supply.

PS

I am operating my laptop right now without it´s battery. :E . If i connect it now, the external supply must be capable to feed the battery too.

The mobiles (most) not operates without the battery. I think is just for cost reduction of the charger. I modified some mobiles using long endurance external batteries connecting them directly to the mobile instead the use of it´s internal battery. When recharging it (recharger set to 4,2 V directly connected to the external battery) the current (from the recharger) divides, part to the external battery and part to the mobile circuitry. A 18650 provides energy for several days of heavy use.

Teething or incompetence?
 

NWA SLF:

Quote:

---

Pilots saving our engineering asses.

---

If the investigation concludes the Li Ion batteries were operating with excessive voltage each cell (> 4,2 V or so) you still will consider that is reasonable transfer the issue to the pilots?

In AF447 case do you consider reasonable the pilots received a non fault tolerant and non gracefully degraded aircraft after encountering ice particles disabling the illusory redundancy created by the design and "maintained" by the carrier and authorities?

Pilots are paid to work operating machines that give chances to them in the event of failures.

A subsystem (battery + charger) in a highly sophisticated and advanced plane presenting this consequences (threatening the program) with smoke, electrolyte spill (inside an electronic bay) fire (BOS), emergency landing (TAK) and evac, IMO is a SHAME.

A redundant and safe DC supply (charger + battery) is an "ancient subsystem" and failures like the ones occurred are unacceptable. Boeing, Yuasa or Thales grounded the Dreamliner creating a Nightmare for everybody involved with the issue.

Something is VERY WRONG. This is very basic: A DC supply (from gennies), a battery and a load (the plane consumption). Difficult to manage? :{

I hope for a charger issue. Hardware, software, whatever. And FAST!

Semantics.

Yes of course aircraft designers always want to save weight and space, and Li-Ion tops the list on those criteria, but that's not the same as saying that the 787 could not have been built without that particular battery technology.

Of course hindsight is a wonderful thing ...

To be able to charge a battery from a circuit powered by that battery then you would have invented perpetual motion, aircraft batteries, like car batteries, are only there to power circuits until the engines are running after which the engine(s) generator(s) take over all the power requirements. With your laptop it's not the battery powering it it's the mains PSU.

Presumably these batteries have to be isolated from the buss by a blocking diode otherwise uncontrolled charging will take place which will cause the battery to overheat. Could it be that there are some nasty spikes on the buss that takes the blocking diode out?

most laptops power from both the Batt and Ac (not 100% of the time though). as the AC adaptor cant provide all the power required, eg a 65watt power brick cant provide full load to a laptop when the laptop is running at 100% and will also take power from the batt if available, if its not, then it will change the cpu/gpu to a lower power mode. If you run your laptop batt flat and plug in the charger, do something cpu/gpu intensive and you will notice the laptop will stop charging and use the full 65watts and then the batt as well (if there is any capacity) . So im guessing the 787 works similar, rather then float charging the li-on all the time , unless there is some special way to float charge a li-on.

any idea if they charge the batt from the 115Vac ? or from the 270Vdc ? on the 787 ? im guessing its easier(cheaper?) to covert from 115Vac to anything that the charger needs, rather then a DC to DC converter ?

New York Times article suggests 787s may not quickly be flying again.

http://www.nytimes.com/2013/01/19/bu...r.html?hp&_r=0

Here is another link from Ars technica on this issue:
Boeing’s Dreamliner batteries “inherently unsafe”

The issue to stress is that these batteries are impossible to put out because they generate oxygen when in thermal runaway. Hence the spectacular roman candle video of what they can do. The safe technology based on LiFePO4 is unfortunately going to result in an approximate doubling of battery weight according to a battery specialist I talked to about this. How much do the batteries of the 787 weigh, so what would be the 'added weight of the solution?

Dreamliner 787 battery fires burn FAA and media too
 

Dreamliner 787 battery fires burn FAA and media too

The FAA and media come out looking foolish or institutionally corrupt as the 787 issues force regulatory responses, because there are other major question marks over this airliner and its certification as safe.

Dreamliner 787 battery fires burn FAA and media too | Plane Talking

Unbelievable.....

hetfield

I thought such practices were the norm. The FAA just does not have appropriate staff to enable it to do otherwise.

Bit like the NTSB who also have to pull in company specialists with many accidents.

Not to belabor the point but at a moment when your device is operating and the battery is being charged, the charger is doing all the work.

As does anyone with more than a superficial knowledge of the certification process. There is nothing new, special or unbelievable here.

Sandilands appear to be looking for publicity by artificial controversy.

No one expects FAA to keep expertise on staff. Their use of Boeing staff is bizarre.

In commercial construction, the authority can require additional or adjunct expertise at will; it does so utilizing independent sources, to avoid obvious conflict. And the engineering is underwritten by the builder.

And it has been that way for years...

Nothing Boeing does is so mysterious or proprietary that they must become the authority on duty of care. Or what constitutes regulation, or best practice.

It is inexcusable in aerospace that it should be this way.

some more detail about ANA trouble
 

How much did the FAA pay BOEING to do the job?

Going deeper
 

wooski

Quote:

---

So im guessing the 787 works similar, rather then float charging the li-on all the time , unless there is some special way to float charge a li-on.

---

We will go deeper to address the issue.

Washington Post reports:



see Tech Log for more details and discussion.

Uncontained failures
 

sb_sfo

Quote:

---

"... two inside the battery and two external, would prevent any serious battery incident."

---

With this degree of redundancy we may think she (batteries) are operating a little bit above safe levels (during recharge at BOS and TAK). I assume in both cases the Systems were recharging her. To higher current levels in Logan. (rear batt used to start APU and being fast charged by APU gennies)

This may lead to a much better scenario: No major design issues, no defective parts, just the need of tweaking. Critical devices normally presents this in their teething. A Li Ion battery is such.

:8 Finger crossing. :8

This investigator may have inside information but I very much doubt anyone can tell the cause from just looking at photos of the burnt remains!

Overdischarge can also cause problems for some Li cells when it's next charged. This is just one of the things that the charging circuit will check (eg that it's not too empty to be charged safely).

NPO19897 :: NASA Tech Briefs

"..overdischarge can result in dissolution of a metal current collector in the anode of a cell, with consequent internal short-circuiting of the cell..."

Single Main Battery Li Ion specs (same for APU)
 

Terego

Quote:

---

How much do the batteries of the 787 weigh, so what would be the 'added weight of the solution?

---

There are 8 LVP65 cells inside a metal case with two protection circuitry in the battery. Ea cell 2,75 Kg (look for LVP65-MSDS.pdf at web).

Estimating: Around 60 pounds

More benign scenario?
 

cwatters,

And additionaly, a tweaking of the algorithms is likely to be required to increase the reliability of the Battery System (Battery + management System)

This may explain severity of BOS incident and characteristics of TAK one. What was common to both? The battery type. (probably the management system too).