Print from Airliners.net discussion forum
http://www.airliners.net/aviation-forums/general_aviation/read.main/5676769/

Topic: FAA Grounds B787 Part 7
Username: 777ER
Posted 2013-01-30 14:31:29 and read 31703 times.

Link to the previous topic FAA Grounds 787 Part 6 (by NZ1 Jan 26 2013 in Civil Aviation)

Please continue the discussion here

Topic: RE: FAA Grounds B787 Part 7
Username: 7BOEING7
Posted 2013-01-30 14:37:09 and read 31747 times.

"Commercial Airplanes' 2013 deliveries are expected to be between 635 and 645 airplanes, which includes greater than 60 787 deliveries."

I think McN is just hedging his bets accounting for a little slippage due to the battery issue. I see a much better number (quality not quantity wise) coming in 3 months when things should be sorted out (hopefully).

Topic: RE: FAA Grounds B787 Part 7
Username: PW100
Posted 2013-01-30 14:51:47 and read 31651 times.

Quotes from previous thread . . . .

Quoting PITingres (Reply 245):
That's exactly what the design does. How is that not clear

We have been going back and forth over this for a couple of iterations now. I think what is meant is not so much why the battery goes to brick/dead/over-discharged or whatever definitions have been used. The question is why the BMS does not have a double threshold?

Threshold 2, 15-20% capacity left (forgive me, I lost the actual percentage). This is the brick condition, or dead as some referred to. In this state, it is not considered "safe" to recharge it, and it should definately not be attempted on the plane. You will have to send it to a specialized repair facility for refurbishment/repair/recharge.

Threshold 1, say 20-20% capacity left. The BMS shuts down the battery and airframe systems in a controlled fashion to prevent it from reaching threshold 2, where the battery must be replaced and sent to a specialized repair facility. This way, you end up with slightly less battery capacity, but you remain with a serviceable battery; all it needs to re-charge the battery is an external power souce. No hassles, no need to replace a $16000 battery, and face an undoubtedly significant repair bill, not to mention any operational inconveniences as these things by nature don't happen in a scheduled fashion.



Elon Musk / Tesla
I find his words very interesting. Basically what he said (and this was stated earlier in this thread by someone else), is that those eight cells are way too big. Boeing (read, the battery supplier) should have used many more cells, with 8 small cells in series to get the required voltage, and many many parallel groups of eight cells to get the required capacity.

There are a couple of problems with these big cells:

1. Local Zoning
They are so big that under some conditions they no longer behave as a homogeneous cell, they start to behave as individual mini cells. In other words, local zones can develop characteristics of mini cells. The problem now is that these local zones are not monitored in detail. Those zones apparently can develop local low voltage/high discharge condition inside the cell, without being detected.
The BMS only monitors the big cell (all 8 of them of course), but can not see in detail what is going on inside each cell, it can not see the local zones.

Basically Musk says this is why Tesla uses hundreds of mini cells instead of Boeing's large super cells (well, actually eight of them). Each Tesla mini cell is monitored indepently. That allows for so much better monitoring in great detail and oversight over the battery condition.
Where the 787 BMS monitors eight cells, Tesla would monitor dozens, of not hundreds of small cells for the same overall capacity.

The Tesla mini cells are so small that it is physically almost impossible for them to have their own small local zones.

2. Heat dissipation
The Tesla mini cells are separated sufficiently to be able to dissipate heat, without seriously affecting adjacent cells. That allows for much better battery temperature control and thermal management.

3.Thermal runaway
Even if a Tesla mini cell goes bezerk, it is sufficiently isolated from adjacent cells to prevent thermal runaway of the whole pack. The thermal runaway is a non-event as it is limited to a single mini cell, with a very small amount of energy (both electric and chjemical) being released.
When a 787 cell goes bezerk, you're pretty much guaranteed to have a big event.


BTW, apparently the Tesla BMS does have a sort of double threshold set-up, as I've not heard or read of any, let alone 100 - 150 of Tesla batteries, having to be changed where those batteries had to be returned to Tesla for safe recharge . . . . but that could be me not paying any attention from the other side of the pond.


Rgds,
PW100

Topic: RE: FAA Grounds B787 Part 7
Username: RickNRoll
Posted 2013-01-30 15:05:47 and read 31548 times.

Should Boeing offer a NiCad option? I think a lot of customers would take it up.

Topic: RE: FAA Grounds B787 Part 7
Username: 7BOEING7
Posted 2013-01-30 15:09:53 and read 31533 times.

Quoting 7BOEING7 (Reply 1):
Elon Musk / Tesla
I find his words very interesting. Basically what he said (and this was stated earlier in this thread by someone else), is that those eight cells are way too big. Boeing (read, the battery supplier) should have used many more cells, with 8 small cells in series to get the required voltage, and many many parallel groups of eight cells to get the required capacity.

Tesla batteries put out 40, 60 or 85kwh are warranted for 8yrs or 100K, 125K, or unlimited miles. They are the entire bottom of he car +/- and weigh I'm guessing 1500-2000 lbs +/-. You replace the whole battery at once and if it's your nickel , it's $8-12K. How does their pwr/lb or pwr/volume relate to the 787 battery??

Topic: RE: FAA Grounds B787 Part 7
Username: AA737-823
Posted 2013-01-30 15:23:44 and read 31436 times.

Quoting RickNRoll (Reply 3):

Should Boeing offer a NiCad option? I think a lot of customers would take it up.

This question has been addressed; a NiCd battery of similar capacity would be too large to fit on the E&E racks. It could have been designed that way from the beginning, but with significant penalties, and at this point it's sort of a "gee-whiz, we coulda done..." head scratch thing.

Topic: RE: FAA Grounds B787 Part 7
Username: ComeAndGo
Posted 2013-01-30 15:26:12 and read 31406 times.

Quoting 7BOEING7 (Reply 4):
How does their pwr/lb or pwr/volume relate to the 787 battery??

8 - 12K vs 16K !! And warranted for 8 years !!

Topic: RE: FAA Grounds B787 Part 7
Username: macc
Posted 2013-01-30 15:26:31 and read 31415 times.

Can I ask all of you a favour? Can u end that endless discussion about the batteries? By now that should be moved over to Tech & Ops. There are so many other aspects which would be interesting to discuss, as the impact of the grounding on various issues. I am a bit fed up by now with that thread.

here is a grounding, period. If for good or not time will tell. But I would be much more interested in how that impacts supply chains, pilots, airlines, leases and other stuff. Unfortunately, that goes under.

Thanks

Topic: RE: FAA Grounds B787 Part 7
Username: tropical
Posted 2013-01-30 15:55:48 and read 31241 times.

Apologies if this has been discussed already- there are too many posts and threads to check. I was wondering if the 787's bleedless engines were a factor in the amount of electric power this bird requires (considerably more than older planes of a similar size IIRC), and if so how this issue might affect future demand for bleedless engines.

I got the feeling that as far as Airbus and many airlines are concerned the jury was still out regarding whether bleedless engines are really the way forward before this problem arose. If using them means more batteries are required than aircraft with conventional engines, airlines might decide bleedless technology is not advantageous enough.

Topic: RE: FAA Grounds B787 Part 7
Username: Shenzhen
Posted 2013-01-30 16:06:11 and read 31167 times.

Quoting tropical (Reply 8):
Apologies if this has been discussed already- there are too many posts and threads to check. I was wondering if the 787's bleedless engines were a factor in the amount of electric power this bird requires (considerably more than older planes of a similar size IIRC), and if so how this issue might affect future demand for bleedless engines.

I got the feeling that as far as Airbus and many airlines are concerned the jury was still out regarding whether bleedless engines are really the way forward before this problem arose. If using them means more batteries are required than aircraft with conventional engines, airlines might decide bleedless technology is not advantageous enough.

I don't think the batteries power anything that uses bleed air on other airplane models.

Cheers

Topic: RE: FAA Grounds B787 Part 7
Username: 7BOEING7
Posted 2013-01-30 16:06:15 and read 31167 times.

Quoting tropical (Reply 8):
Apologies if this has been discussed already- there are too many posts and threads to check. I was wondering if the 787's bleedless engines were a factor in the amount of electric power this bird requires (considerably more than older planes of a similar size IIRC), and if so how this issue might affect future demand for bleedless engines.

I got the feeling that as far as Airbus and many airlines are concerned the jury was still out regarding whether bleedless engines are really the way forward before this problem arose. If using them means more batteries are required than aircraft with conventional engines, airlines might decide bleedless technology is not advantageous enough.

No, the battery requirements would have been the same with engines using bleed air.

Topic: RE: FAA Grounds B787 Part 7
Username: cornutt
Posted 2013-01-30 16:08:00 and read 31172 times.

Quoting PW100 (Reply 2):
Threshold 1, say 20-20% capacity left. The BMS shuts down the battery and airframe systems in a controlled fashion to prevent it from reaching threshold 2,

The problem with that is: think about the legal implications if the battery has to be used during a flight and it shuts down on threshold 1. Even if the flight lands safety, lawyers will be lining up to sue the airline and Boeing for emotional distress: "There was power still available, and your system didn't allow the plane to use it?" Now we all know what the deal is, but that's the sort of thing that can be demagouged to an ignorant jury.

Quoting tropical (Reply 8):
I got the feeling that as far as Airbus and many airlines are concerned the jury was still out regarding whether bleedless engines are really the way forward before this problem arose. If using them means more batteries are required than aircraft with conventional engines, airlines might decide bleedless technology is not advantageous enough.

The battery really doesn't have much to do with that, though. Remember that the 787 batteries only have two jobs: (1) start the APU, and (2) power a few essential systems when there is no other source of power. The only time you'd need the batteries in flight would be if both engines flamed out (or all four engine generators failed), the APU was failed or not running, and the RAT failed to deploy.

Topic: RE: FAA Grounds B787 Part 7
Username: SonomaFlyer
Posted 2013-01-30 16:25:18 and read 31066 times.

Quoting macc (Reply 7):

Can I ask all of you a favour? Can u end that endless discussion about the batteries?

Sir the batteries are the reason this a/c was grounded. The fact they necessarily must check the charging system and how the containment system worked adds to the complexity of the problem. If you don't want to deal with batteries, you'd best just ignore these "787 grounded" threads.

I'd love to stop reading and talking about the issue but that likely won't happen until the 787 returns to service.
  

Topic: RE: FAA Grounds B787 Part 7
Username: PITingres
Posted 2013-01-30 17:00:06 and read 30908 times.

Quoting PW100 (Reply 2):
The question is why the BMS does not have a double threshold?

Just a guess on my part, but I'm going to suggest a) on-battery duration was thought to be more important than avoiding replacement (that's the "don't do that" argument), and possibly a related b) you'd have to allow several minutes at least for the power-up margin, and then a margin on top of that to make sure that you meet the specs for that power-up margin, and by that time you might be taking too large a slice out of the on-battery duration.

In other words, doing that might have required an x% larger battery for some significant x, and the designers didn't think it was worth it, and presumably whatever airlines were consulted agreed.

Whether anyone is regretting the decision at this point I've no idea.

Topic: RE: FAA Grounds B787 Part 7
Username: Stitch
Posted 2013-01-30 17:09:09 and read 30864 times.

Quoting PW100 (Reply 2):
The question is why the BMS does not have a double threshold?

Because it increases complexity and the fault tree.

You have to prove that the battery will only disconnect at a level greater than 20% when another power source if available (Engine Generator, APU Generator, RAT) and would continue to discharge below 20% when it was the only power source for the airplane.



Quoting macc (Reply 7):
Can u end that endless discussion about the batteries? By now that should be moved over to Tech & Ops. There are so many other aspects which would be interesting to discuss, as the impact of the grounding on various issues

We already know that even a permanent grounding of the 787 and cancellation of all outstanding orders, while a tremendous financial hit to Boeing, would not spell the end of Boeing Commercial. They'd sell hundreds of 767s and 777s in place of 787s because Airbus could not meet demand with the A330 and A350.

Anything less than a permanent grounding just defers Boeing's revenues to the right and temporarily increases inventory costs as frames back up prior to the fix being implemented and deliveries resume.

Topic: RE: FAA Grounds B787 Part 7
Username: Aesma
Posted 2013-01-30 17:29:08 and read 30778 times.

And I'd like to put to rest the idea that we'll know in the future if the grounding was a good idea or not. This is known right now, if not by us (if you're not convinced) then at least by the ones in charge. Even if it turns out, after a lengthy inquiry, that there was no danger of an accident, that has no impact on the initial decision to ground the plane.

Topic: RE: FAA Grounds B787 Part 7
Username: cornutt
Posted 2013-01-30 17:46:28 and read 30699 times.

Quoting Stitch (Reply 14):
Anything less than a permanent grounding just defers Boeing's revenues to the right and temporarily increases inventory costs as frames back up prior to the fix being implemented and deliveries resume.

In the time that I worked at Boeing, the company surrendered up more than $1B thanks to the Uncle Mikey scandal, and wrote off $800M over a small accounting rules change. This 787 business looks like a drop in the bucket by comparison. It's never nice to lose money, but perspective.

Topic: RE: FAA Grounds B787 Part 7
Username: RickNRoll
Posted 2013-01-30 17:52:16 and read 30676 times.

The Seatlle times link has a video of a Lithium Ion Battery undergoing a meltdown with nothing more than a few wisps of smoke escaping from the containment. It appears it is possible to contain the result of a meltdown without creating an explosive effect.

Topic: RE: FAA Grounds B787 Part 7
Username: NAV20
Posted 2013-01-30 18:07:08 and read 30604 times.

I don't know whether this infornation has been posted before - if so, apologies for the repetition. But it appears to prove that a high proportion of the batteries have been giving frequent trouble ever since the aeroplane entered service; but the relevant authorities were simply not informed of the problems. The article is 'silent' on the question of how much Boeing knew about the problems:-

"Japan's two major airlines said Wednesday they had replaced a number of batteries in their Dreamliners after experiencing problems well before the worldwide grounding of Boeing's next generation plane.

A spokeswoman for All Nippon Airways said 10 batteries on its fleet had been switched, while a representative of rival Japan Airlines (JAL) said "quite a few" had needed changing.

"The lithium-ion batteries, made by Japanese manufacturer GS Yuasa, have been at the centre of a probe into the Dreamliner's airworthiness since a fire on a JAL plane in Boston and an emergency landing on an ANA flight in Japan.

"ANA, the launch customer for Boeing's lightweight plane, had to replace batteries 10 times ahead of the January 16 emergency landing forced by smoke apparently linked to the powerpack, company spokeswoman Naoko Yamamoto said.

"The airline, which started operating Boeing 787s in November 2011, had to replace some batteries after only a week while others lasted only a month, she said.

"In four cases, the main powerpack was only partially charged, while in two other cases a battery or an auxiliary power unit - which boosts the battery - failed to start, she said.

"All 10 replacements occurred last year - two in May, four in October, two on one day in November and two in December - involving seven Dreamliners, she said. The airline operates 17 of the planes.

"ANA had not reported the replacements to the Japan Transport Safety Board (JTSB) because "the ten problems were found before flights so were considered not to affect safety", Yamamoto said."


Read more: http://www.theage.com.au/travel/trav...-20130131-2dmbc.html#ixzz2JVwlxdTh

On the face of it, it looks as if Boeing will have no option but to replace ALL the batteries with more reliable and proven types? However long it takes to develop, test, and certify them?

[Edited 2013-01-30 18:09:22]

Topic: RE: FAA Grounds B787 Part 7
Username: Stitch
Posted 2013-01-30 18:24:15 and read 30528 times.

Quoting NAV20 (Reply 18):
I don't know whether this infornation has been posted before - if so, apologies for the repetition. But it appears to prove that a high proportion of the batteries have been giving frequent trouble ever since the aeroplane entered service; but the relevant authorities were simply not informed of the problems.

It was discussed at length in Part 6.

The reason the relevant authorities were not informed of the problems is because these were cases of the battery's safety features working as designed. So there was no "problem" to report, at least in terms of safety. The authorities now want to review those batteries to see if they can shed insights onto the two that caught fire.



Quoting NAV20 (Reply 18):
On the face of it, it looks as if Boeing will have no option but to replace ALL the batteries with more reliable and proven types? However long it takes to develop, test, and certify them?

I would expect Boeing will move to a safer electrolyte material, if not as a condition to return to service, then as a subsequent change to improve safety and reliability in conjunction with whatever measures are taken to return to service. Newer formulations that have been developed since the original battery was designed / certified are much stabler.

Topic: RE: FAA Grounds B787 Part 7
Username: XT6Wagon
Posted 2013-01-30 18:40:11 and read 30448 times.

Quoting Stitch (Reply 19):
I would expect Boeing will move to a safer electrolyte material

My bet too, Its the massive lead time to design and certify systems for Aircraft that really hurt innovation in the detail like a battery chemistry change. Who is going to be willing to pay huge money and wait years for a slightly better battery.

But it looks like in this case Boeing can select a much safer chemistry than was practical at the time they started designing the 787 battery system... and the FAA has some pretty huge incentive to do all it can to get it approved if it meets the requirements.

Topic: RE: FAA Grounds B787 Part 7
Username: tdscanuck
Posted 2013-01-30 18:42:50 and read 30457 times.

Quoting PW100 (Reply 2):
Threshold 1, say 20-20% capacity left. The BMS shuts down the battery and airframe systems in a controlled fashion to prevent it from reaching threshold 2, where the battery must be replaced and sent to a specialized repair facility.

Why would you sacrifice the airframe to protect the battery?

Quoting PW100 (Reply 2):
This way, you end up with slightly less battery capacity, but you remain with a serviceable battery; all it needs to re-charge the battery is an external power souce.

No, the whole point is that, once you hit what you're calling "Threshold 2" you have to electrically separate the battery from the aircraft. That's an FAA requirement. Once you do that, you can't recharge it without reconnecting it. That means either you replace it (the solution they chose) or you put in a reversible disconnect...the latter opens two huge fault options up, neither of which is good. Swapping LRU's is a whole lot simpler (and almost certainly cheaper).

Quoting PW100 (Reply 2):
Basically Musk says this is why Tesla uses hundreds of mini cells instead of Boeing's large super cells (well, actually eight of them). Each Tesla mini cell is monitored indepently.

Each Boeing cell is monitored independantly too. I'm not a battery guy...does the size of the cell impact the ability to monitor it?

Quoting PW100 (Reply 2):
Where the 787 BMS monitors eight cells, Tesla would monitor dozens, of not hundreds of small cells for the same overall capacity.

Doesn't that greatly increase the complexity off the BMS, an hence the probability of a BMS or cell failure?

Quoting PW100 (Reply 2):
BTW, apparently the Tesla BMS does have a sort of double threshold set-up, as I've not heard or read of any, let alone 100 - 150 of Tesla batteries, having to be changed where those batteries had to be returned to Tesla for safe recharge . . . . but that could be me not paying any attention from the other side of the pond.

Tesla doesn't have a requirement from the FAA to sever the battery from the car, or to guarantee that the car is absolutely, positively, never without power. An unpowered car rolls to a stop. An unpowered airplane...

Quoting tropical (Reply 8):
I was wondering if the 787's bleedless engines were a factor in the amount of electric power this bird requires (considerably more than older planes of a similar size IIRC), and if so how this issue might affect future demand for bleedless engines.

They're a huge factor in the amount of power the airplane requires. However, that has essentially nothing to do with the battery size or design. Also, "bleedless engines" are relatively easy to convert to bleed engines...the 747-8 flies around on what is basically a GEnX with a smaller fan and bleed ports.

Quoting tropical (Reply 8):
If using them means more batteries are required than aircraft with conventional engines, airlines might decide bleedless technology is not advantageous enough.

It doesn't mean more (or bigger) batteries are required.

Quoting RickNRoll (Reply 17):
It appears it is possible to contain the result of a meltdown without creating an explosive effect.

There is no evidence that the meltdown on either 787 created an explosive effect. A fire and leakage are not the same thing as an explosion.

Quoting NAV20 (Reply 18):
I don't know whether this infornation has been posted before - if so, apologies for the repetition.

It's been posted before. The short version is that the vast majority of those replacements, assuming the articles are correct, are the result of the batteries operating *correctly* in the face of being run down in service.

Tom.

Topic: RE: FAA Grounds B787 Part 7
Username: RickNRoll
Posted 2013-01-30 18:51:27 and read 30386 times.

Quoting tdscanuck (Reply 21):
There is no evidence that the meltdown on either 787 created an explosive effect. A fire and leakage are not the same thing as an explosion.

I didn't say there was. I had been saying they could just build a more substantial container, but people said that would just create an bomb that could explode. The video shows the container holding in the result of the thermal runaway with no hint of fire or solids breaking out.

Topic: RE: FAA Grounds B787 Part 7
Username: NAV20
Posted 2013-01-30 18:53:47 and read 30381 times.

Quoting Stitch (Reply 19):
Newer formulations that have been developed since the original battery was designed / certified are much stabler.
Quoting XT6Wagon (Reply 20):
But it looks like in this case Boeing can select a much safer chemistry than was practical at the time they started designing the 787 battery system...

Thanks for the replies, guys. But are those 'stabler' and 'safer' versions already in service and fully tested? Or will Boeing have to be the 'pioneer' again?

Topic: RE: FAA Grounds B787 Part 7
Username: PHX787
Posted 2013-01-30 19:00:02 and read 30344 times.

ok hello guys, I've pretty much handed off the whole "japan" side of things to the guys who are technically involved with the 787 (like tdscanuck), so pretty much anything translated or coming out of Japan is pretty much old news by now.

Now I have a question:
1) progress on the investigation?
2) Any guesses on when the 787 will fly again?
3) Rumors were floating in Japan about lawsuits coinciding with these batteries; would that happen?
4) According to Japan Today the JTM investigation shifted from Yuasa to a Kyoto company which makes products that monitors overcharge, charge exchange, and other components which allow the battery to work. Japan Today couldn't explain more about it; what's the investigation going to be like there?
5) What's the updates on the replacement service?

PHX787

Topic: RE: FAA Grounds B787 Part 7
Username: ComeAndGo
Posted 2013-01-30 19:30:00 and read 31219 times.

Quoting PHX787 (Reply 24):
2) Any guesses on when the 787 will fly again?

next year . . .

Topic: RE: FAA Grounds B787 Part 7
Username: btfarrwm
Posted 2013-01-30 19:46:56 and read 31205 times.

If most of the problem with the Lithium Ion batteries has to do with improper charging and discharging, as the recent New York Times Article would suggest, how much of a design change would be required to make the batteries removable? Batteries could be charged and inspected at facilities on the ground and then changed in and out with every flight. If it works for Makita and DeWalt power tools, it should probably works for Boeing (tounge in cheek, of course).

Topic: RE: FAA Grounds B787 Part 7
Username: SonomaFlyer
Posted 2013-01-30 19:47:40 and read 32247 times.

Quoting ComeAndGo (Reply 25):

Quoting PHX787 (Reply 24):
2) Any guesses on when the 787 will fly again?

next year . . .

It won't be that long. There are too many engineers and too much riding on this a/c to have the grounding last that long.

Topic: RE: FAA Grounds B787 Part 7
Username: Stitch
Posted 2013-01-30 19:55:21 and read 32163 times.

Quoting NAV20 (Reply 23):
Thanks for the replies, guys. But are those 'stabler' and 'safer' versions already in service and fully tested? Or will Boeing have to be the 'pioneer' again?

It would depend on the formulation.

As I understand it, the 787's batteries use lithium cobalt oxide with manganese. The manganese was added to improve service durability. Nissan and it's partners developed lithium nickel manganese cobalt (NMC) in 2008, and evidently the addition of the nickel reduces volatility. I could see Boeing looking at this formulation since it is similar to what they already have and it does have high energy density (like lithium cobalt oxide).




Quoting btfarrwm (Reply 26):
If most of the problem with the Lithium Ion batteries has to do with improper charging and discharging, as the recent New York Times Article would suggest, how much of a design change would be required to make the batteries removable?

The current batteries are removable by design.

Topic: RE: FAA Grounds B787 Part 7
Username: spacecadet
Posted 2013-01-30 20:06:27 and read 32014 times.

Quoting RickNRoll (Reply 17):
It appears it is possible to contain the result of a meltdown without creating an explosive effect.

You can contain the result of a nuclear blast with a big and strong enough containment vessel (just watch an underground test from above sometime). That doesn't mean it's practical to carry on an airplane.

The whole point of the lithium ion batteries is to have a lighter battery. If the containment vessel makes the battery overall as big and heavy as a different, older technology, then you may as well just use that older technology.

Topic: RE: FAA Grounds B787 Part 7
Username: Skydrol
Posted 2013-01-30 20:57:24 and read 31715 times.

Quoting tdscanuck (Reply 21):
Each Boeing cell is monitored independantly too. I'm not a battery guy...does the size of the cell impact the ability to monitor it?

On small or large cells, it is possible to monitor the voltage of each cell with equal accuracy.

The problem with larger cells is that different areas of the electrode or plates within a single cell can see more current flow during charging and discharging than other areas, resulting in localized hot spots.

By having mutiple cells in a series/parallel arrangement (in the case of a 28V Li-Ion battery, maybe 24 or 32), the individual cells (and their electrodes or plates) get smaller, and can be montored for temperature with even more precision. As well as monitoring individual cell voltages, the current flow through each parallel group can be measured and compared for load balance vs. other parallel groups.

Proper voltage, current, temperature and cell load balance monitoring and control, coupled with cooling fins for individual smaller cells, and cooling fans can make for a very robust, reliable battery unit.



✈ LD4 ✈

Topic: RE: FAA Grounds B787 Part 7
Username: sonic67
Posted 2013-01-30 21:11:06 and read 31724 times.

Is their a chance that Boeing would take Musk on his offer or is it just PR stunt?

Elon Musk offers Boeing SpaceX batteries for the 787 Dreamliner
http://www.geek.com/articles/geek-ce...s-for-the-787-dreamliner-20130129/

[Edited 2013-01-30 21:21:38]

Topic: RE: FAA Grounds B787 Part 7
Username: RickNRoll
Posted 2013-01-30 21:17:23 and read 31687 times.

Quoting spacecadet (Reply 29):
The whole point of the lithium ion batteries is to have a lighter battery. If the containment vessel makes the battery overall as big and heavy as a different, older technology, then you may as well just use that older technology.

I don't think that's the priority any more. Getting the planes in the air is. It has been suggested going back to the older technology, that's not an option apparently.

Topic: RE: FAA Grounds B787 Part 7
Username: p201055r
Posted 2013-01-31 00:08:30 and read 30465 times.

More from Boeing

http://www.independent.ie/breaking-n...xe-dreamliner-battery-3370880.html

Topic: RE: FAA Grounds B787 Part 7
Username: EBGflyer
Posted 2013-01-31 00:12:16 and read 30462 times.

A little more from Musk saying the 787 are fundamentally unsafe:

http://www.flightglobal.com/news/art...ttery-fundamentally-unsafe-381627/

Topic: RE: FAA Grounds B787 Part 7
Username: Unflug
Posted 2013-01-31 00:27:01 and read 30281 times.

Quoting p201055r (Reply 33):
More from Boeing

Quote from this article:

"Boeing said about 2,000 batteries of all types were replaced every year on its various planes."


How many Boeing aircraft are currently flying? I'd guess more than 2.000, so less than 1 battery per year to be replaced. Apparently the number for the 787 is significantly higher - if the reported number of 100 to 150 was correct.

This higher replacement rate was certainly not intended. The higher maintenance cost it causes is not a security threat by itself, but still points to a design flaw in that area. At least, a less than perfect design.

[Edited 2013-01-31 00:46:28]

Topic: RE: FAA Grounds B787 Part 7
Username: AeroWesty
Posted 2013-01-31 00:47:17 and read 30119 times.

Quoting EBGflyer (Reply 34):
A little more from Musk saying the 787 are fundamentally unsafe:

The war of words continues. Musk and the MIT professor Sadoway claim Boeing doesn't have the engineering to prevent the domino effect which increases the risk of a thermal runaway within the battery packs. Meanwhile, Boeing's Sinnett claims that not only do they have that engineering, they've also designed the appropriate containment to keep planes safe if thermal runaway does occur.

Where do they go from there?

Topic: RE: FAA Grounds B787 Part 7
Username: rheinwaldner
Posted 2013-01-31 01:01:30 and read 29931 times.

From the last thread I only take over this quote, because PW100 wrote a great post about the rest:

Quote:
Sinnett flat out said they designed for a battery fire...how can you say that they didn't anticipate the root cause?

Because very likely the nature of the found root cause will be so basic, that still saying "we fully trust our design" after these events have happened will a bit strange. I mean on the picture everybody can see that the design is not good at the prevention of failure propagation between cells. The picture and real world events are in an agreement. Boeings claims not.

Quoting PW100 (Reply 2):

Wise post!

Quoting PW100 (Reply 2):
Threshold 1, say 20-20% capacity left. The BMS shuts down the battery and airframe systems in a controlled fashion to prevent it from reaching threshold 2

I have thought to quickly propose a draft for such such a two-level-battery controlling system, but then you did it!

I would propose in addition an emergency switch, that manually allows the crew to suppress Threshold1 in case every bit of power is needed up to the Threshold2. In that case the available power could be used in an emergency case until the battery locks. But not if the mechanics does a handling error like keeping a light on somewhere.

Quoting PW100 (Reply 2):
There are a couple of problems with these big cells:

Again your wrote very precise what I think could be the case.

Quoting XT6Wagon (Reply 20):
Quoting Stitch (Reply 19):
I would expect Boeing will move to a safer electrolyte material

My bet too, Its the massive lead time to design and certify systems for Aircraft that really hurt innovation in the detail like a battery chemistry change.

Any other electrloyte would reduce the batteries capacity. So there would be structural changes anyway to make the battery accordingly larger.

Quoting tdscanuck (Reply 21):
No, the whole point is that, once you hit what you're calling "Threshold 2" you have to electrically separate the battery from the aircraft. That's an FAA requirement.

That's fine. And beside that there could a threshold 1, that would be reversible. Even my RC craft has two built in levels of low-voltage protection and additional levels are added by external gear.

Quoting tdscanuck (Reply 21):
I'm not a battery guy...does the size of the cell impact the ability to monitor it?

Tesla and SpaceX say so. I could easily imagine this to be the case.

Quoting tdscanuck (Reply 21):
Quoting PW100 (Reply 2):
Where the 787 BMS monitors eight cells, Tesla would monitor dozens, of not hundreds of small cells for the same overall capacity.

Doesn't that greatly increase the complexity off the BMS, an hence the probability of a BMS or cell failure?

You have to do what is required. For the cost of simple but burning batteries you can install a lot of (still simple) electronics.

Quoting tdscanuck (Reply 21):
Tesla doesn't have a requirement from the FAA to sever the battery from the car, or to guarantee that the car is absolutely, positively, never without power. An unpowered car rolls to a stop. An unpowered airplane...

So one wonders why their design does properly cover all three safety levels, that are mentioned by Sinnet, while the Dreamliners design is poor in two of them. Had the dreamliner Teslas battery it would stay longer with battery power.

Topic: RE: FAA Grounds B787 Part 7
Username: justloveplanes
Posted 2013-01-31 02:57:06 and read 28933 times.

Quoting XT6Wagon (Reply 20):
I would expect Boeing will move to a safer electrolyte material

My bet too, Its the massive lead time to design and certify systems for Aircraft that really hurt innovation in the detail like a battery chemistry change. Who is going to be willing to pay huge money and wait years for a slightly better battery.

This was my previous thought until I read this.....

Quoting PW100 (Reply 2):
1. Local Zoning
They are so big that under some conditions they no longer behave as a homogeneous cell, they start to behave as individual mini cells. In other words, local zones can develop characteristics of mini cells. The problem now is that these local zones are not monitored in detail. Those zones apparently can develop local low voltage/high discharge condition inside the cell, without being detected. .......

The Tesla mini cells are so small that it is physically almost impossible for them to have their own small local zones.

3.Thermal runaway
Even if a Tesla mini cell goes bezerk, it is sufficiently isolated from adjacent cells to prevent thermal runaway of the whole pack. The thermal runaway is a non-event as it is limited to a single mini cell, with a very small amount of energy (both electric and chjemical) being released.....

If this is indeed true (The Tesla approach), it seems to me a permanent solution. Just a more robust (and larger and more expensive) design. It is a very simple principle used in many other solutions. Circuit board designs have limits on cross interferance from traces and limit the size of PCB's (can only make them so small). This may be the same phenomena here from a heat perspective. One day I think bigger cells can work with proper manufacturing, but apparently not there yet (impurities and other factors may cause this local zoning is a possibility).

The distributed approach mitigates risk on two levels, runaway and voltage/current loss of a cell (since a single cell is much less of the total pack). It seems a much better solution. Musk makes a compelling argument, with real world product experience to back it up; Tesla obviously took this expensive design path for a reason and apparently to avoid the incidents we are seeing now. I would think NTSB would be satisfied if such a solution was adopted to reduce incidents and was combined with neater containment/venting for accidental electrolyte discharge.

Topic: RE: FAA Grounds B787 Part 7
Username: XT6Wagon
Posted 2013-01-31 03:09:19 and read 28849 times.

Quoting justloveplanes (Reply 38):
(The Tesla approach)

The problem with the Tesla idea is certification. They don't have to certify it to any standard other than bad press, much less to FAA arbitrary and sometimes counterproductive regs.

ask yourself how many cells would the FAA let go dead before mandating a diversion. How many before replacement of the battery. Tesla wants to put hundreds of cells into a regulatory environment where even benign failure can be the source for massive trouble. Heck look at AA's trouble with the FAA being indecisive about ziptie spacing on MD80's with absolutely no evidence that there was a problem TO FIX. Now you are suggesting a large and massively complex battery replacing a simpler design.

You might convince me that doubling the cell count while running 1/2 the size might be possible, but 20x or more? hahaha good luck. At some point redundancy is counter productive. The Airline industry seems to quickly adopt solutions that while expensive mean that you only need a absolute minimum of back ups, extra capacity, or other redundancy factors. The fact that twin engine airliners are the safest, most reliable planes around should show you just how this ideal is achieved in the real world. More engines for the sake of "redundancy" just adds more potential failure points into the design.

Topic: RE: FAA Grounds B787 Part 7
Username: rheinwaldner
Posted 2013-01-31 04:07:45 and read 28371 times.

Quoting justloveplanes (Reply 38):
Just a more robust (and larger and more expensive) design. It is a very simple principle used in many other solutions. Circuit board designs have limits on cross interferance from traces and limit the size of PCB's (can only make them so small). This may be the same phenomena here from a heat perspective.

I agree. This might turn out to be the main contributing factor. I mean 76Ah from each single cell is huge.

Quoting justloveplanes (Reply 38):
The distributed approach mitigates risk on two levels, runaway and voltage/current loss of a cell (since a single cell is much less of the total pack).

Correct.

Quoting XT6Wagon (Reply 39):
The problem with the Tesla idea is certification. They don't have to certify it to any standard other than bad press, much less to FAA arbitrary and sometimes counterproductive regs.

No, it should be easier as it fulfills the standards of the FAA probably better than Boeings approach. So providing evidence for certification should be easier.

Quoting XT6Wagon (Reply 39):
Ask yourself how many cells would the FAA let go dead before mandating a diversion.

The FAA has asked for zero cells to go dead (implicitely because even a single dead cell will infringe one or more of the defined requirements). This does not depend on the cellcount. So why not choose a cell size, that is inherently more stable?

Topic: RE: FAA Grounds B787 Part 7
Username: nomadd22
Posted 2013-01-31 04:38:26 and read 27981 times.

Quoting tdscanuck (Reply 21):

Tesla doesn't have a requirement from the FAA to sever the battery from the car, or to guarantee that the car is absolutely, positively, never without power. An unpowered car rolls to a stop. An unpowered airplane...

The whole point is, Tesla doesn't have to sever the battery because it's not a single string of huge cells. They can disconnect a single series of cells with very little impact on the battery capacity. A cell failure with them is almost unnoticeable. Potential for fire and loss of battery are pretty much eliminated.

Topic: RE: FAA Grounds B787 Part 7
Username: sphealey
Posted 2013-01-31 04:54:22 and read 27811 times.

Quoting XT6Wagon (Reply 39):
The problem with the Tesla idea is certification. They don't have to certify it to any standard other than bad press, much less to FAA arbitrary and sometimes counterproductive regs.

Automobile certifications and aircraft certifications have some similarities and many, many differences, but autos are certainly very heavily regulated and have extremely detailed certification requirements. And just as with the 787 in the airline world the (re-) development of electric cars has caused thousands of pages of new cert reqs to be written. Again, may or may not be relevant to the 787 situation, but let's be technically and legally accurate in our discussion.

sPh

Topic: RE: FAA Grounds B787 Part 7
Username: seahawk
Posted 2013-01-31 05:22:44 and read 27476 times.

Tesla solution sounds possible, but then the whole pack with become larger and heavier and you will have to redesign and re-certify the whole rack installation, battery and charger system. I guess it would be way safer to switch the battery type in that case as well.

Topic: RE: FAA Grounds B787 Part 7
Username: par13del
Posted 2013-01-31 05:38:39 and read 27317 times.

Quoting seahawk (Reply 43):
Tesla solution sounds possible, but then the whole pack with become larger and heavier and you will have to redesign and re-certify the whole rack installation, battery and charger system. I guess it would be way safer to switch the battery type in that case as well.

In which case the Telsa solution goes away, if you are going to redesign to get that much space for the additional size of the batterires, may as well go ni-cad one time and be done with it, why continue with a technology that everyone is up in arms about?

Topic: RE: FAA Grounds B787 Part 7
Username: tdscanuck
Posted 2013-01-31 05:49:18 and read 27279 times.

Quoting RickNRoll (Reply 22):
I didn't say there was. I had been saying they could just build a more substantial container, but people said that would just create an bomb that could explode. The video shows the container holding in the result of the thermal runaway with no hint of fire or solids breaking out.

The argument about explosion risk was about *sealed* battery cases. As you said:

Quoting RickNRoll (Reply 17):
nothing more than a few wisps of smoke escaping from the containment.

If wisps of smoke are escaping, it's not a sealed case, hence doesn't build pressure, hence isn't explosive. We already had people yelling, at considerably length, that release of flammable gas was totally unacceptable and that's what the battery you describe was doing.

Quoting PHX787 (Reply 24):
3) Rumors were floating in Japan about lawsuits coinciding with these batteries; would that happen?

I'm not sure...who, exactly, would they sue and for what? Airliner contracts are *huge*...it's hard to imagine there is some wrong that's sue-able that isn't already covered in the contract.

Quoting btfarrwm (Reply 26):
If most of the problem with the Lithium Ion batteries has to do with improper charging and discharging, as the recent New York Times Article would suggest, how much of a design change would be required to make the batteries removable?

They're already removable. In aviation parlance, the battery is an LRU (Line Replaceable Unit). There's usually a design goal that all LRU's should be able to be replaced in some finite time for maintenance reasons...on the order of 30-60 minutes is common. Some LRU's are worse, some are better. Swapping a battery is actually on the faster end.

Quoting Unflug (Reply 35):
How many Boeing aircraft are currently flying? I'd guess more than 2.000, so less than 1 battery per year to be replaced. Apparently the number for the 787 is significantly higher - if the reported number of 100 to 150 was correct.

Quite a lot more than 2,000...the active Boeing fleet (including heritage MD) is close to 10,000. However, it's a mistake to think the battery replacement rate should be constant across the fleet...electrical demand (and certification requirements) have gone *way* up. The battery situation on an MD-80 is not remotely close to that of a 777.

Quoting rheinwaldner (Reply 37):
Quoting tdscanuck (Reply 21):
Doesn't that greatly increase the complexity off the BMS, an hence the probability of a BMS or cell failure?

You have to do what is required. For the cost of simple but burning batteries you can install a lot of (still simple) electronics.

I didn't ask about cost, I asked about complexity and probability of failure. The battery is the last line of defense for the electrical system and (for the main battery) not on the MMEL. Reliability is a lot more important that cost. I fully agree that having batteries catch fire is not an indication of reliability but I don't see how injecting even more complexity and failure modes into the BMS is going to to help the reliability situation.

Quoting rheinwaldner (Reply 37):
Had the dreamliner Teslas battery it would stay longer with battery power.

Had the Dreamliner the Tesla's battery it would not have been certified and would not be flying today.

Quoting rheinwaldner (Reply 40):
Quoting XT6Wagon (Reply 39):
The problem with the Tesla idea is certification. They don't have to certify it to any standard other than bad press, much less to FAA arbitrary and sometimes counterproductive regs.

No, it should be easier as it fulfills the standards of the FAA probably better than Boeings approach

It fails the FAA special conditions for battery certification on its face:

Quoting nomadd22 (Reply 41):
The whole point is, Tesla doesn't have to sever the battery because it's not a single string of huge cells. They can disconnect a single series of cells with very little impact on the battery capacity.

Without a rewrite of the regulations or a redesign of the battery, Tesla's battery is blatantly uncertifiable.

Quoting rheinwaldner (Reply 40):
Quoting XT6Wagon (Reply 39):
Ask yourself how many cells would the FAA let go dead before mandating a diversion.

The FAA has asked for zero cells to go dead (implicitely because even a single dead cell will infringe one or more of the defined requirements). This does not depend on the cellcount. So why not choose a cell size, that is inherently more stable?

The probability of a cell failure sounds like it goes up with cell size, but it also scales up with the number of cells...if you go from 8 to 800 cells, you need to improve the cell reliability by a factor of 100 to maintain the same system-level reliability. Is that realistic?

Tom.

Topic: RE: FAA Grounds B787 Part 7
Username: nomadd22
Posted 2013-01-31 06:33:05 and read 26740 times.

Quoting tdscanuck (Reply 45):
The probability of a cell failure sounds like it goes up with cell size, but it also scales up with the number of cells...if you go from 8 to 800 cells, you need to improve the cell reliability by a factor of 100 to maintain the same system-level reliability. Is that realistic?

I sure the heck don't know anything about the certification, but that just doesn't make sense to me. A cell failure when you have 800 cells isn't a system failure and has no real impact on the system. Writing the standard so a cell failure that has no impact other than a 1% drop in battery capacity is the same as a cell failure that causes total battery failure and meltdown sounds more than a little insane to me. By disallowing the Tesla type architecture, the FAA has required a battery that's less reliable, and has a much greater chance of causing real problems when it fails.

[Edited 2013-01-31 06:34:52]

Topic: RE: FAA Grounds B787 Part 7
Username: rheinwaldner
Posted 2013-01-31 06:39:44 and read 26680 times.

Quoting tdscanuck (Reply 45):
I fully agree that having batteries catch fire is not an indication of reliability but I don't see how injecting even more complexity and failure modes into the BMS is going to to help the reliability situation.

You have to weight up the complexity increase by the risk reduction of going to smaller cells.

What we do know, is that millions small-cell batteries (less than maybe 10Ah per cell) are in use and can be considered as proven. They did cause troubles to some degrees in consumer applications, but in a professional environment they should be manageable to perform safely.

The Dreamliners >70Ah cells are called inherently unsafe by people who only build vehicles that can be left at the roadside the latest 15 seconds after the wish to do so.

Quoting tdscanuck (Reply 45):
Without a rewrite of the regulations or a redesign of the battery, Tesla's battery is blatantly uncertifiable.

It does not need to be Teslas battery. There are different requirements for cars e.g. in the area of crash impact.

But the principles of the Tesla battery should be valid for the dreamliner:
- Reduce cell size.
- Have a layout, where at least a bit better separation can be achieved.

Quoting tdscanuck (Reply 45):
The probability of a cell failure sounds like it goes up with cell size, but it also scales up with the number of cells...if you go from 8 to 800 cells, you need to improve the cell reliability by a factor of 100 to maintain the same system-level reliability. Is that realistic?

Tesla's batteries seem to be more stable overall. Otherwise we would have heard the incidents by now. So the 100 times more complex BMS seems to be outweighted by more than 100 times more stable cells.

Topic: RE: FAA Grounds B787 Part 7
Username: tdscanuck
Posted 2013-01-31 06:48:36 and read 26626 times.

Quoting rheinwaldner (Reply 47):
So the 100 times more complex BMS seems to be outweighted by more than 100 times more stable cells.

If that's really true, I can't see why they'd go for the giant-cell architecture, except maybe maximum power density.

Quoting nomadd22 (Reply 46):
I sure the heck don't know anything about the certification, but that just doesn't make sense to me. A cell failure when you have 800 cells isn't a system failure and has no real impact on the system.

What the FAA wrote (that's relevant here) was:
(i) A battery temperature sensing and over-temperature warning
system with a means for automatically disconnecting the battery from
its charging source in the event of an over-temperature condition,
or,
(ii) A battery failure sensing and warning system with a means
for automatically disconnecting the battery from its charging source
in the event of battery failure.

I think the applicability would require the FAA to concede that the over-temperature of a *cell* was permissible as long as it didn't over-temp the battery, and that failure of a cell could not be considered failure of the battery.

My read on it is that the FAA special condition wasn't written to take that kind of hundreds-of-levels-of-redundancy at the cell level into account.

Tom.

Topic: RE: FAA Grounds B787 Part 7
Username: cornutt
Posted 2013-01-31 07:14:09 and read 26256 times.

Quoting nomadd22 (Reply 46):
I sure the heck don't know anything about the certification, but that just doesn't make sense to me. A cell failure when you have 800 cells isn't a system failure and has no real impact on the system. Writing the standard so a cell failure that has no impact other than a 1% drop in battery capacity is the same as a cell failure that causes total battery failure and meltdown sounds more than a little insane to me.

Consider the reliability and redundancy requirements. If you have 800 cells, you have a massively complex BMS with 800 sets of sensors, 800 signal conditioning circuits, and 800 relays so that individual cells can be taken off line. Can the BMS detect faults in all of that circuitry so as to maintain redundancy? What happens if an isolation relay fails to switch? Can you detect it, and if you can, do you take the whole battery offline? Even if you can line up all of the testing and all of the paperwork to show that it's safe and get it certified, you've created a maintenance nightmare due to the complexity of the system.

As far as Elon Musk goes, if I was working for him right now, I'd be ashamed. His remarks have not been helpful, and his using the issue to grandstand and draw attention to himself is very unseemly. He seems to forget that a lot of the people he's calling idiots are the same people that he's trying to get to come work for him.

Topic: RE: FAA Grounds B787 Part 7
Username: Stitch
Posted 2013-01-31 07:18:22 and read 26255 times.

Quoting rheinwaldner (Reply 37):
Any other electrloyte would reduce the batteries capacity. So there would be structural changes anyway to make the battery accordingly larger.

It depends on the electrolyte. Lithium nickel manganese cobalt has high energy density and high energy output (like lithium cobalt oxide), so it might very well provide the same performance with the same cell dimensions as the current battery. Lithium iron phosphate, which has a lower energy density, has been reported to be able to provide the same performance with one additional cell.

Topic: RE: FAA Grounds B787 Part 7
Username: ServantLeader
Posted 2013-01-31 09:17:51 and read 25050 times.

There is no way the FAA will let the 787 fly with the current lithium ion battery system -- too much evidence that it is unreliable and unsafe -- this will mean a complete redesign and a minimum of 18 months on the ground. This is going to leave a mark.

Topic: RE: FAA Grounds B787 Part 7
Username: PW100
Posted 2013-01-31 09:32:31 and read 24822 times.

Quoting AA737-823 (Reply 5):
This question has been addressed; a NiCd battery of similar capacity would be too large to fit on the E&E racks. It could have been designed that way from the beginning, but with significant penalties, and at this point it's sort of a "gee-whiz, we coulda done..." head scratch thing.

I would be absolutely flabbergasted if Boeing didn't have a team working full steam on this. I'm pretty sure that they have several core teams working separately on different solutions and options, ranging from setting extra inspection intervals for the existing battery, containment actions, to a (temporary) replacement of a different design and chemistry.
.

Quoting PITingres (Reply 13):
Just a guess on my part

Probably very close to intial design choices.
.

Quoting Stitch (Reply 14):
Because it increases complexity and the fault tree

While that might be the case, complexity has never stopped the industry from introducing new technologies. That's why today's aeroplanes are much more efficient than those of 20 years ago. If it's worth it, it'll be done, eventually.
.

Quoting tdscanuck (Reply 21):
Why would you sacrifice the airframe to protect the battery?

Because it is no different then a slightly lower capacity battery freezing up and sacrificing the same airframe because of the BMS protecting the battery against over-dis-charge (which seems to be the situation with the majority of the rumoured 100 - 150 battery replacements to date).
.

Quoting tdscanuck (Reply 21):
No, the whole point is that, once you hit what you're calling "Threshold 2" you have to electrically separate the battery from the aircraft

That is still the case in the described scenario. Only difference is that you will not reach that level, because of the extra safety features embedded in the BMS logic. So you won't have to replace the battery.

Off course, this scenario has a great deal of hindsight advantage, as I agree that Boeing probably did not foresee the large amounts (100 - 150 as rumoured) of battery replacements because of apparent over-dis-charge, to date.
.

Quoting tdscanuck (Reply 21):
Each Boeing cell is monitored independantly too. I'm not a battery guy...does the size of the cell impact the ability to monitor it?

That is (amongst others) what's being suggested, if not claimed by Mr Musk (and also earlier described in the previous thread by fellow member rheinwaldner).
.

Quoting tdscanuck (Reply 21):
Doesn't that greatly increase the complexity off the BMS . . .

Again, while that might be the case, complexity has never stopped the industry from introducing new technologies. I'm sure you would agree that's why today's aeroplanes are much more efficient than those of 20 years ago. If it's worth it, it'll be done, eventually

Quoting tdscanuck (Reply 21):
. . . , and hence the probability of a BMS or cell failure?

Good question. I'm not able to judge that.
Worthwhile mentioning,Tesla experience using the same battery chemistry seems to suggest they have this under control.
.

Quoting tdscanuck (Reply 21):
Tesla doesn't have a requirement from the FAA to sever the battery from the car, or to guarantee that the car is absolutely, positively, never without power. An unpowered car rolls to a stop. An unpowered airplane...

Agreed. The automotive industry has different regulations with respect to safety.

However, considering public exposure and outcry if something goes wrong (ie Toyota's US throttle nightmares - PR-wise), automotive has come a long way towards extreme reliability standards. That should not be underestimated. The thing is that where aerospace produces hundreds or thousands of airframes of a specific model at most, automotive production produces millions of cars of a specific model. The numbers are at least a factor 10^3 larger than typical airliners. That does have a big impact in probability analysis.



Rgds,
PW100

Topic: RE: FAA Grounds B787 Part 7
Username: JoeCanuck
Posted 2013-01-31 09:48:32 and read 24569 times.

Quoting NAV20 (Reply 23):

Thanks for the replies, guys. But are those 'stabler' and 'safer' versions already in service and fully tested? Or will Boeing have to be the 'pioneer' again?

Cessna is testing, (and may already have certified), Lithium Iron Phosphate batteries for their CJ-4.

Quoting btfarrwm (Reply 26):
If most of the problem with the Lithium Ion batteries has to do with improper charging and discharging, as the recent New York Times Article would suggest, how much of a design change would be required to make the batteries removable?

If you look at the famous Sony laptop failures, their runaways were caused by contamination, not improper charging. I understand the investigators have already ruled out improper charging in the 787 cases.

Quoting rheinwaldner (Reply 37):
Any other electrloyte would reduce the batteries capacity. So there would be structural changes anyway to make the battery accordingly larger.

There are other Lithium battery chemistries which have been calculated to fit into the current 787 battery box.

Quoting Stitch (Reply 50):
Lithium iron phosphate, which has a lower energy density, has been reported to be able to provide the same performance with one additional cell.
Quoting ServantLeader (Reply 51):
There is no way the FAA will let the 787 fly with the current lithium ion battery system -- too much evidence that it is unreliable and unsafe -- this will mean a complete redesign and a minimum of 18 months on the ground. This is going to leave a mark.

The could if the faults were manufacturing flaws. Eliminate those and you eliminate the dangers. Couple that with more robust containment, and most issues would be resolved. The current containment was robust enough to contain enough of the residue and energy from the runaway batteries to prevent serious damage to the plane...a better system could surely be found for that.

Topic: RE: FAA Grounds B787 Part 7
Username: PITingres
Posted 2013-01-31 10:09:40 and read 24333 times.

Quoting ServantLeader (Reply 51):
There is no way the FAA will let the 787 fly with the current lithium ion battery system ... this will mean a complete redesign and a minimum of 18 months on the ground.

Well, I'm glad THAT's settled.  

Topic: RE: FAA Grounds B787 Part 7
Username: alberchico
Posted 2013-01-31 10:31:15 and read 24078 times.

Just a moment of light humor to provide a brief interlude:

http://diytravelexpert.com/wp-content/uploads/2013/01/2013-01-22-cw0696.jpg

Given the FAA's reputation as a ''tombstone agency'' we should be lucky this problem was spotted and addressed as quickly as it was....

Topic: RE: FAA Grounds B787 Part 7
Username: Stitch
Posted 2013-01-31 10:39:26 and read 23954 times.

Quoting alberchico (Reply 55):
Given the FAA's reputation as a ''tombstone agency'' we should be lucky this problem was spotted and addressed as quickly as it was....

The FAA is hardly the only regulatory body in the US, much less the world, with that kind of mentality.

Topic: RE: FAA Grounds B787 Part 7
Username: strfyr51
Posted 2013-01-31 11:21:13 and read 23454 times.

Quoting tropical (Reply 8):

So far as we can tell from working the airplane, the electrical load on the airplane is actually pretty well in the normal range.
Lord KNOWS there's enough power on the airplane for the electrical load. The Bleed less engines are to preserve power in climb and cruise and to increase the fuel economy as there's nothing coming off the gas path of the engines that does NOT produce power out of the exhaust. the lack of Bleed related valves, inter stage, Press regulating, High Pressure, Nose cowl anti-icing, are the key to the range and at this point the 787 with Bleeds would be not much more than the 767 in Carbon Fiber. I'm looking for the engines to be on wing 65-75,000 Hours barring environmental damage.
Even if they can stay on 50-60,000 hours they will have nearly paid for themselves in efficiency.

Topic: RE: FAA Grounds B787 Part 7
Username: packsonflight
Posted 2013-01-31 11:23:45 and read 23504 times.

Quoting rheinwaldner (Reply 47):
But the principles of the Tesla battery should be valid for the dreamliner:
- Reduce cell size.
- Have a layout, where at least a bit better separation can be achieved.

Possibly the reason why Airbus is going with 4 batteries for the A350
On top of that I guess that total battery capacity is way smaller given the conventional architecture of the aircraft.

Topic: RE: FAA Grounds B787 Part 7
Username: SFORunner
Posted 2013-01-31 11:46:07 and read 23203 times.

Semi-interesting article in the New Yorker.

http://www.newyorker.com/talk/financ...013/02/04/130204ta_talk_surowiecki

Quote:
The Dreamliner was supposed to become famous for its revolutionary design. Instead, it’s become an object lesson in how not to build an airplane.

To understand why, you need to go back to 1997, when Boeing merged with McDonnell Douglas. Technically, Boeing bought McDonnell Douglas. But, as Richard Aboulafia, a noted industry analyst with the Teal Group, told me, “McDonnell Douglas in effect acquired Boeing with Boeing’s money.” McDonnell Douglas executives became key players in the new company, and the McDonnell Douglas culture, averse to risk and obsessed with cost-cutting, weakened Boeing’s historical commitment to making big investments in new products.


Quote:
“Some of the board of directors would rather have spent money on a walk-in humidor for shareholders than on a new plane,” Aboulafia says. So the Dreamliner’s advocates came up with a development strategy that was supposed to be cheaper and quicker than the traditional approach: outsourcing.


Quote:
In 2011, Jim Albaugh, who took over the program in 2009, said, “We spent a lot more money in trying to recover than we ever would have spent if we’d tried to keep the key technologies closer to home.” And the missed deadlines created other issues. Determined to get the Dreamliners to customers quickly, Boeing built many of them while still waiting for the F.A.A. to certify the plane to fly; then it had to go back and retrofit the planes in line with the F.A.A.’s requirements.

Topic: RE: FAA Grounds B787 Part 7
Username: cornutt
Posted 2013-01-31 11:54:32 and read 23023 times.

Quoting strfyr51 (Reply 57):
the lack of Bleed related valves, inter stage, Press regulating, High Pressure,

Not to mention that by getting rid of bleed air, you eliminate a significant fire hazard.

Topic: RE: FAA Grounds B787 Part 7
Username: justloveplanes
Posted 2013-01-31 12:13:55 and read 22783 times.

Quoting tdscanuck (Reply 48):
I think the applicability would require the FAA to concede that the over-temperature of a *cell* was permissible as long as it didn't over-temp the battery, and that failure of a cell could not be considered failure of the battery.

I think that is the correct approach, because as you pointed out, the current regs may have been written with the current 787 in mind. With the new design, failures are tolerable to a certain percent of storage capacity, current delivery or voltage deviation. Within say, 5 %, should be good to go and enough to make it to the next airfield as a normal condition. Ideally, individual cells could be replaced, lowering maintenance costs and reducing necessary inventory at airfields.

Topic: RE: FAA Grounds B787 Part 7
Username: AeroWesty
Posted 2013-01-31 12:19:48 and read 22729 times.

Quoting SFORunner (Reply 59):
Semi-interesting article in the New Yorker.

And it gets its very first paragraph wrong:

"Its braking, pressurization, and air-conditioning systems are run not by hydraulics but by electricity from lithium-ion batteries."

Topic: RE: FAA Grounds B787 Part 7
Username: cornutt
Posted 2013-01-31 12:25:18 and read 22671 times.

Quoting AeroWesty (Reply 62):
And it gets its very first paragraph wrong

First rule of working in the aerospace industry: Never, ever listen to anything the mainstream media has to say about aerospace. Yeah, I trust the New Yorker on technical issues about as much as I trust Jim Albaugh on cuisine issues.

Topic: RE: FAA Grounds B787 Part 7
Username: RickNRoll
Posted 2013-01-31 12:31:15 and read 22562 times.

Quoting tdscanuck (Reply 45):

If wisps of smoke are escaping, it's not a sealed case, hence doesn't build pressure, hence isn't explosive. We already had people yelling, at considerably length, that release of flammable gas was totally unacceptable and that's what the battery you describe was doing.

But if a small amount or smoke is all that is vented out, then it is going to be pretty easy to have a dedicated tube to vent it to the outside directly through the existing vents. There must be a lot more going on inside that case, so I'm guessing this is a pressure relief valve to limit how much pressure is contained inside.

Topic: RE: FAA Grounds B787 Part 7
Username: rcair1
Posted 2013-01-31 12:37:45 and read 22522 times.

Quoting rheinwaldner (Reply 37):
see that the design is not good at the prevention of failure propagation between cells.
Quoting PW100 (Reply 2):
BTW, apparently the Tesla BMS does have a sort of double threshold set-up, as I've not heard or read of any, let alone 100 - 150 of Tesla batteries,

But you can brick them. There are big warnings about not letting your Tesla get too discharged.
BTW - if you brick your tesla - it is not covered under warranty - and the cost to replace the battery is $40K, not the $12K here. That $12K is the pre-plan price you can pay toward replacement at the end. To be fair - not many Teslas have bricked. The new model S's have more aggressive brick control procedures - so it is less likely.

While Tesla is cool - let's stop making like they are the god's of batteries. Plenty of problems with Telsa's.

Too other things about Teslas
- Major driver in the battery choice was cost - these are standard 'off the shelf' batteries.
- Complexity and lower reliability - they are complex. Cells can die - and they allow the car to continue to run - because they know cells will die. How many cells would you allow to die on your 787 before you replaced them? Certification nightmare. What if a cell burned up - and you did such a good job isolating it - you just though it died. Is that 'fire' acceptable - well - depends on the containment.... Hmmmm

The point is - there are design trade-offs that must be made for any battery system. It is really easy to sit here in my office in Colorado and second guess the engineers designing it - but as an EE, I've been on the other side. too

Quoting 7BOEING7 (Reply 4):
and if it's your nickel , it's $8-12K.
Quoting ComeAndGo (Reply 6):
8 - 12K vs 16K !! And warranted for 8 years !!

$40K if they brick - warrenty does not cover it.

Quoting tdscanuck (Reply 21):
Doesn't that greatly increase the complexity off the BMS, an hence the probability of a BMS or cell failure?

Yes - Twins versus Quads. Which is more reliable (from the previous string). Twins....

Topic: RE: FAA Grounds B787 Part 7
Username: 7BOEING7
Posted 2013-01-31 12:47:18 and read 22375 times.

Quoting packsonflight (Reply 58):
Possibly the reason why Airbus is going with 4 batteries for the A350
On top of that I guess that total battery capacity is way smaller given the conventional architecture of the aircraft.

As was noted above, the evolutionary "architecture" of the airplane has nothing to do with the battery requirement.

Quoting tdscanuck (Reply 21):
They're a huge factor in the amount of power the airplane requires. However, that has essentially nothing to do with the battery size or design.

Topic: RE: FAA Grounds B787 Part 7
Username: rheinwaldner
Posted 2013-01-31 13:06:33 and read 22144 times.

Quoting tdscanuck (Reply 48):
If that's really true, I can't see why they'd go for the giant-cell architecture, except maybe maximum power density.

Maybe because on paper the weight of the containment would turn out the lowest. A compact cube offers the largest volume per surface area. That means for a given volume of content, the weight of the shell would be minimized. So having more space between cells and another layout would require more steel (or whatever other material) for the containment.

That might be one argument for the current cramped layout. Possibly again a case of too much emphasis on weigth reduction.

Quoting cornutt (Reply 49):
If you have 800 cells, you have a massively complex BMS with 800 sets of sensors, 800 signal conditioning circuits, and 800 relays so that individual cells can be taken off line.

- First the dreamliner would never need 800 cells. Between 8 and 800 there is wide range were a reasonable cellcount could end up. So maybe 160 would be fine (a so called 8s20p-battery).

- Second such a battery would not require 160 (temperature) sensors. The primary parameter to monitor and control is voltage. For temperature monitoring thermography in combination with digital image recognition would be a clever, cheap and 787-worthy solution. Also smoke and fire detection are possible for a larger area of cells.

- Third the signal conditioning would be very cheap technology in the whole context even with 160 cells.

- Fourth you don't need a single relay to cut off a cell. Have you seen the massive, fix steal connectors between the cells on the existing battery? There is no relay! So why would you need relays for the smaller cells if the current whopper-cells don't have one? Just to complete: electronic switches will do that job.

Here is a link where the challenges of large format cells are discussed for automotive applications:
http://www.lithiumbalance.com/automo...e/battery-management-in-automotive

Specifically safety is mentioned as the single biggest challenge with such batteries:
Safety is the single biggest challenge for large format Lithium Ion cells. Smaller cells such as the typical 18650 size cells can be equipped with built-in, passive, safety features. In advent of a mishap, a single cell with a capacity of 2.2AH (9Wh) is of manageable impact compared with a 50AH or even 400AH (1.6kWH) unit.

Topic: RE: FAA Grounds B787 Part 7
Username: cornutt
Posted 2013-01-31 13:57:30 and read 21654 times.

Quoting rheinwaldner (Reply 67):
- First the dreamliner would never need 800 cells. Between 8 and 800 there is wide range were a reasonable cellcount could end up. So maybe 160 would be fine (a so called 8s20p-battery).

So if I understand the terminology, that's 8 "layers" of 20 parallel cells each.

Quoting rheinwaldner (Reply 67):
- Second such a battery would not require 160 (temperature) sensors. The primary parameter to monitor and control is voltage. For temperature monitoring thermography in combination with digital image recognition would be a clever, cheap and 787-worthy solution. Also smoke and fire detection are possible for a larger area of cells.

The thermography would be a cool solution if it had been thought of about four years ago. There's no way in hell that software gets developed to DO-178C standards and certified in a few months, even with people working on it 24/7. As a long-range improvement it's worth looking at, but it isn't going to solve the immediate problem.

Quoting rheinwaldner (Reply 67):
- Third the signal conditioning would be very cheap technology in the whole context even with 160 cells.

It's a reliability issue. Might be solvable; I haven't had occasion to look at A-spec parts for that sort of thing in a while, so parts with the necessary reliability numbers might be available now. Last time I looked they weren't, but that was years ago.

Quoting rheinwaldner (Reply 67):
- Fourth you don't need a single relay to cut off a cell. Have you seen the massive, fix steal connectors between the cells on the existing battery? There is no relay! So why would you need relays for the smaller cells if the current whopper-cells don't have one? Just to complete: electronic switches will do that job.

The current battery has no cell cutouts because there is no point; with all of the cells in series, the battery can't achieve spec voltage with one cell bypassed. If a cell fails, it cuts out the whole battery (at least in theory). Presumably, with a multi-cell battery, we want to continue to operate with some number of cells failed so that we overcome the failure probability calculation with multiple cells. The problem that arises is: what if a cell shorts? If it does that, then even if the resulting event is fully contained to that cell, you've still got the problem of having a short across that layer. That will prevent other cells in the layer from charging and lower the overall battery voltage. (And no, I don't think you can just assume that the short will always burn itself out... carbon tracking and all that...)

So you need to be able to cut out individual cells, or small groups of cells, and once they are cut out you need for them to say cut out until the battery is serviced. Latching relays make a tidy solution for that; the BMS causes the relay to open, and then it stays open until reset via voltage applied to a test bus which the flight system has no connection to. If you do it with electronic devices, the BMS has to remember which ones to keep open, and it has to retain this information across power cycles. That's some more complexity; not a lot, but it's one more bit of software and complex hardware to certify. And the electronic devices themselves probably don't save space or weight vs. the latching relays, considering the amount of current they have to carry.

Look, there are some good ideas here. But it's not as simple as "oh pop this in, and the 787s will be flying again next week". And I'm particularly resenting the implication that the problem would be easily solvable, or could have been entirely avoided in the first place, except for Boeing engineers being stubborn and stupid. We've got some posts here simultaneously arguing that the certification criteria for the existing design should have been a lot more strict, and that they can bypass all those criteria with some magic bit of technology. There is no such thing as a zero-risk solution, and to argue otherwise is dishonest.

Topic: RE: FAA Grounds B787 Part 7
Username: RickNRoll
Posted 2013-01-31 14:21:59 and read 21606 times.

Rumor of a fix Boeing is considering.

"Sources say that Boeing is seriously considering a better containment system that solves both the collateral damage to other sensitive equipment and deals with the smoke better. The plan is to build a stronger and larger containment box or dome around the battery, and vent smoke and potential debris overboard through a hose or other channel. "

http://www.king5.com/news/aerospace/...87-battery-problems-189115821.html

Which seems to be in line with I what I have been seeing as a possible solution.

Just a rumor from "sources" though, at the moment.

Topic: RE: FAA Grounds B787 Part 7
Username: blrsea
Posted 2013-01-31 14:32:04 and read 21351 times.

Quoting RickNRoll (Reply 69):
"Sources say that Boeing is seriously considering a better containment system that solves both the collateral damage to other sensitive equipment and deals with the smoke better. The plan is to build a stronger and larger containment box or dome around the battery, and vent smoke and potential debris overboard through a hose or other channel. "

Looks similar to the way the other company was making for Cessna. I believe the details of that company are in the previous thread.

Topic: RE: FAA Grounds B787 Part 7
Username: ComeAndGo
Posted 2013-01-31 16:01:53 and read 21071 times.

Quoting rcair1 (Reply 65):
Yes - Twins versus Quads. Which is more reliable (from the previous string). Twins....

unless of course you're virgin and that A330 hits a flock of vultures on take off in Orlando and both engines are out.

Topic: RE: FAA Grounds B787 Part 7
Username: Kaiarahi
Posted 2013-01-31 17:03:08 and read 20808 times.

Quoting ComeAndGo (Reply 71):
unless of course you're virgin and that A330 hits a flock of vultures on take off in Orlando and both engines are out.

And here was I thinking this was an aviation forum - virgins, vultures?

Topic: RE: FAA Grounds B787 Part 7
Username: NAV20
Posted 2013-01-31 17:26:29 and read 20776 times.

Quoting RickNRoll (Reply 69):
Which seems to be in line with I what I have been seeing as a possible solution.

Just a rumor from "sources" though, at the moment.

This story adds the point that the solution would probably be 'interim in nature.'

"The actual mechanics of this would of course be more complex, but the principle of containment and disposal of risk are straightforward, and possibly interim in nature if the unofficial reports are correct.

"The reports make more sense of the confidence Boeing management expressed for a prompt solution to the problem during an earnings conference call earlier this week."


http://blogs.crikey.com.au/planetalk...aks-a-fix-while-ana-seeks-damages/

Pretty obviously the only way Boeing (and the airlines) can hope to get the aircraft back in the air in the short term.

Topic: RE: FAA Grounds B787 Part 7
Username: packsonflight
Posted 2013-01-31 17:28:43 and read 20757 times.

Quoting RickNRoll (Reply 69):
Just a rumor from "sources" though, at the moment.

King5 is not the most respected news outlet...

I think we will be witnessing the 787 delay PR spin all over again. How many delays did Boeing officially announce on the 787 program? was it more than 10 or more than 20? In hindsight we see that the management at no time announced more than a fraction of the delay needed at each time.

Take for example the infamous Potemkin rollout of the 787. If the management did not realise the troubles the program was in at that time, they should not be trusted to run a hotdog stand, let alone the mighty Boeing company.

Topic: RE: FAA Grounds B787 Part 7
Username: Stitch
Posted 2013-01-31 17:54:43 and read 20692 times.

Quoting packsonflight (Reply 74):
King5 is not the most respected news outlet...

They are in Seattle, so they likely have better access to Boeing personnel working on the issue than, say, The New Zealand Herald.



Quoting packsonflight (Reply 74):
I think we will be witnessing the 787 delay PR spin all over again.

As Boeing will not be the one controlling return to service, I am not sure how they can "delay" it to the point they need to spin.

Topic: RE: FAA Grounds B787 Part 7
Username: tdscanuck
Posted 2013-01-31 18:57:52 and read 20543 times.

Quoting PW100 (Reply 52):
Quoting tdscanuck (Reply 21):
Why would you sacrifice the airframe to protect the battery?

Because it is no different then a slightly lower capacity battery freezing up and sacrificing the same airframe because of the BMS protecting the battery against over-dis-charge

Yes, it's hugely different. You're talking about giving the battery the ability to shut down the airplane (that's "Threshold 1" in this scenario). That's what I mean by sacrificing the airplane to save the battery. The current battery can't shut the airplane down, it will continue to power it for as long as it can.

On it's face, the two threshold idea is uncertifiable because you've set up, by design, a single-point failure that will take down the airplane. If the Threshold 1 "nice shutdown" activates in flight you're going to die.

Quoting ServantLeader (Reply 51):
this will mean a complete redesign and a minimum of 18 months on the ground.

How do you get 18 months? Boeing (with Thales and Hamilton-Sunstrand) managed to redesign, retrofit, test, and certify a hugely more complex change to the power system in 6 months after the ZA002 power panel issue.

Quoting packsonflight (Reply 58):
On top of that I guess that total battery capacity is way smaller given the conventional architecture of the aircraft.

No. The battery capacity is driven, primarily, by the need to keep critical avionics running in the event of total power failure. The A350 and 787 have basically the same avionics architecture and requirements. The unique electrical architecture on the 787 has nothing to do with the batteries.

Quoting packsonflight (Reply 74):
How many delays did Boeing officially announce on the 787 program? was it more than 10 or more than 20?

Less than 10.

Tom

Topic: RE: FAA Grounds B787 Part 7
Username: packsonflight
Posted 2013-01-31 19:19:16 and read 20600 times.

Quoting Stitch (Reply 75):
As Boeing will not be the one controlling return to service, I am not sure how they can "delay" it to the point they need to spin.

By now I guess Boeing has a pretty good idea what has to be done to get the 787 in to the air again, and what the timeframe will be, but I guess they keep saying the service entry is right around the corner...

Quoting tdscanuck (Reply 76):
The unique electrical architecture on the 787 has nothing to do with the batteries.

So you are saying that the capacity of the 787 battery is similar to a battery from a 767 and 330?

Topic: RE: FAA Grounds B787 Part 7
Username: prebennorholm
Posted 2013-01-31 19:20:23 and read 20610 times.

Quoting RickNRoll (Reply 69):
"Sources say that Boeing is seriously considering a better containment system that solves both the collateral damage to other sensitive equipment and deals with the smoke better. The plan is to build a stronger and larger containment box or dome around the battery, and vent smoke and potential debris overboard through a hose or other channel. "

This is one of the "solutions" which was brought forward here at a.net already in thread #1. It deals with the collateral damage and smoke/smell issues, but it adds weight, takes up space, and it doesn't deal with the reliability issue.

When Boeing says that they sold 2000 replacement batteries for "old type planes" last year, then we can easily calculate that batteries on average last a few years, even if "old planes" have only one single battery - I have no idea how many planes have multiple batteries like the 787, if any.

From a maintenance perspective, won't airlines expect 787 batteries to be at least as reliable as present norm? At least since this rumor indicates that the weight advantage will go away or be much reduced by additional hardware.

Such a system will, if implemented, become a little more complicated than described. The containment box, or dome, will need its own ventilation system, and its outflow pressure valve will have to be made to deal with the thick paste from a thermal runaway to let the gasses/smoke get out, or a filter or other separation system must be included.

Topic: RE: FAA Grounds B787 Part 7
Username: prebennorholm
Posted 2013-01-31 19:53:46 and read 20502 times.

Quoting packsonflight (Reply 77):
So you are saying that the capacity of the 787 battery is similar to a battery from a 767 and 330?

That's correct. The APU battery is dimensioned to start the APU. Whether the APU shall provide power by compressed air or electric power to start the main engines, that doesn't mean any significant size difference of the APU. Very likely electric power is in fact more efficient, allowing a smaller APU?

If you think about the batteries providing power for actually moving flight controls for any significant time, extending flaps/spoilers, provide anti icing, etc, forget it. If you run out of main engine generators, APU, and RAT at 30,000 feet, then you are no better off than in a traditional airliner. That will never happen, therefore the batteries serve the same purposes as on other airliners.

Those batteries have a capacity of around roughly 2 kw/h each. One could power your vacuum cleaner for a couple of hours, but it could no way wash your underwear in your washing machine.

There has been much talk on this thread about Li-Ion batteries on electric cars. That was relevant from a technology point of view. But these 787 batteries are 20 - 40 times smaller than the batteries of full size electric cars, which are specified with 200+ miles range. One could move a Tesla about 6-7 miles. Maybe 8-9 miles because the Tesla car would be a half ton lighter with a 787 battery only.

[Edited 2013-01-31 20:08:53]

Topic: RE: FAA Grounds B787 Part 7
Username: francoflier
Posted 2013-01-31 20:17:21 and read 20429 times.

Quoting prebennorholm (Reply 79):
, but it could no way wash your underwear in your washing machine.

Hang on. Short cycle, low temperature, I think it could...
 
Quoting prebennorholm (Reply 78):
I have no idea how many planes have multiple batteries like the 787

It is my belief that most airliners have 2 batteries. In fact, even small turboprops have 2 batteries as well.

Quoting prebennorholm (Reply 79):
That will never happen, therefore the batteries serve the same purposes as on other airliners.

Isn't one of the major differences the fact that it replaces the park brake accumulator in the 787?
No big drain though.

Topic: RE: FAA Grounds B787 Part 7
Username: RickNRoll
Posted 2013-01-31 20:41:25 and read 20332 times.

Quoting francoflier (Reply 80):
Isn't one of the major differences the fact that it replaces the park brake accumulator in the 787?
No big drain though.

Why were so many batteries being locked out because they had been drained compeletly?

Topic: RE: FAA Grounds B787 Part 7
Username: rheinwaldner
Posted 2013-01-31 21:13:40 and read 20253 times.

Quoting rcair1 (Reply 65):
and the cost to replace the battery is $40K, not the $12K here

The cost difference is, because the Tesla battery has much higher capacity. More than four times higher.

Quoting cornutt (Reply 68):
Presumably, with a multi-cell battery, we want to continue to operate with some number of cells failed so that we overcome the failure probability calculation with multiple cells.

You can take cells out of order by simply applying the exact same voltage to the cell, that the cell would have if it would be disconnected. If you do that, no longer any current flows through the cell. This could be achieved during charging by reducing the voltage across one cell until the whole current, that flows through the string of the other cells flows parallely to that to that cell. If the voltage would be reduced below the cell idle voltage, the cell would change into discharging mode, which is also not what we want. So applying the cells idle voltage would be the goal.

Quoting cornutt (Reply 68):
If you do it with electronic devices, the BMS has to remember which ones to keep open, and it has to retain this information across power cycles.

The BMS needs a memory for a lot more things anyway.

Quoting cornutt (Reply 68):
But it's not as simple as "oh pop this in, and the 787s will be flying again next week". And I'm particularly resenting the implication that the problem would be easily solvable

Absolutely, correcting this battery will take a long time.

Quoting cornutt (Reply 68):
or could have been entirely avoided in the first place, except for Boeing engineers being stubborn and stupid.

It could have been avoided by a more conservative design. Using still Lithium batteries.

Quoting RickNRoll (Reply 69):
"Sources say that Boeing is seriously considering a better containment system that solves both the collateral damage to other sensitive equipment and deals with the smoke better.

Bandaid tactics IMO.

Topic: RE: FAA Grounds B787 Part 7
Username: spacecadet
Posted 2013-01-31 21:26:27 and read 20202 times.

Quoting packsonflight (Reply 77):
By now I guess Boeing has a pretty good idea what has to be done to get the 787 in to the air again, and what the timeframe will be

I don't see how they have any better idea than the NTSB does at this point, given that the NTSB are leading the investigation and have said flat out that they have no idea what Boeing needs to do to get the 787 back in the air yet.

Quoting RickNRoll (Reply 69):
Rumor of a fix Boeing is considering.

This fix wouldn't accomplish anything as far as getting the plane back in the air unless Boeing has some inside information from the FAA about doing and end-run around the NTSB. This solution doesn't seem to solve the NTSB's main problem at all, which is that destructive battery failures are happening way too frequently on the 787.

Unless Boeing is actively conspiring with the FAA on a way to get the 787 flying before the NTSB releases its findings and recommendations, then they're just tilting at windmills with this "solution". Either that or the rumor is baseless.

The third possibility is that Boeing intentionally leaked this information to gauge reaction from sources inside the FAA and/or NTSB.

Topic: RE: FAA Grounds B787 Part 7
Username: 7BOEING7
Posted 2013-01-31 21:28:27 and read 20224 times.

Quoting rheinwaldner (Reply 82):
Quoting RickNRoll (Reply 69):"Sources say that Boeing is seriously considering a better containment system that solves both the collateral damage to other sensitive equipment and deals with the smoke better.
Bandaid tactics IMO.

That's the way many AD's are handled--come up with procedures or a "quick fix" hardware/software wise--get the airplanes back in the air safely--come up with the ideal solution down the road--happens a lot.

Topic: RE: FAA Grounds B787 Part 7
Username: ADent
Posted 2013-01-31 22:28:28 and read 20060 times.

Quoting spacecadet (Reply 83):
I don't see how they have any better idea than the NTSB does at this point, given that the NTSB are leading the investigation and have said flat out that they have no idea what Boeing needs to do to get the 787 back in the air yet

At some point Boeing needs to come out and say "No more Li-Ion on 787" and retrofit NiCd batteries and get the 787s back in the air - just like Cessna did with the Citation CJ4.

I don't need KING 5 to tell me this plan is detailed out and sitting on an executives desk. If the long lead tasks have not been started (software is my guess) then management should be changed.

Topic: RE: FAA Grounds B787 Part 7
Username: seahawk
Posted 2013-01-31 22:50:02 and read 19963 times.

If they fix the containment, they fixed the problem. How often the batteries fail is not a safety concern.

Topic: RE: FAA Grounds B787 Part 7
Username: packsonflight
Posted 2013-01-31 23:04:34 and read 19968 times.

Quoting tdscanuck (Reply 76):
How do you get 18 months? Boeing (with Thales and Hamilton-Sunstrand) managed to redesign, retrofit, test, and certify a hugely more complex change to the power system in 6 months after the ZA002 power panel issue.

That was easy. The only thing Thales had to do was to put a sticker above the switch panel reading:

"WARNING In order to avoid FOD take your screwdriver with you when you leave the E/E!"

Topic: RE: FAA Grounds B787 Part 7
Username: Unflug
Posted 2013-02-01 00:06:39 and read 19742 times.

Quoting tdscanuck (Reply 76):
Yes, it's hugely different. You're talking about giving the battery the ability to shut down the airplane (that's "Threshold 1" in this scenario). That's what I mean by sacrificing the airplane to save the battery. The current battery can't shut the airplane down, it will continue to power it for as long as it can. On it's face, the two threshold idea is uncertifiable because you've set up, by design, a single-point failure that will take down the airplane. If the Threshold 1 "nice shutdown" activates in flight you're going to die.

Here I don't understand your line of thought (probably for the first time). As I understood, the batteries will normally not be discharged in flight. It was stated several times that the over discharge taking the batteries out of normal operation must have occurred on the ground. Neither the first nor the second threshold should ever be reached in flight.

The second threshold would reduce the amount of energy the battery is able to provide by maybe 5% or 10%. If this reduction would bring down an aircraft, the design with this specific battery size would have to be called not certifiable anyway.

Topic: RE: FAA Grounds B787 Part 7
Username: XT6Wagon
Posted 2013-02-01 00:21:37 and read 19673 times.

Quoting Unflug (Reply 88):
Here I don't understand your line of thought (probably for the first time). As I understood, the batteries will normally not be discharged in flight. It was stated several times that the over discharge taking the batteries out of normal operation must have occurred on the ground. Neither the first nor the second threshold should ever be reached in flight.

It doesn't matter if it "shouldn't" happen, you don't want to tell the regulators that the battery that is the last line of defense against power loss to critical systems will call it a day earlier than it might otherwise have because you want to save a little money. Trust me the FAA would much rather see you say "the battery will set itself on fire to get the last joule to the flight control systems" than "the battery shuts off at 10% above absolute minimum to prevent needing to remove the battery for bench testing". The first indicates you know just how bad things have gotten if you have no engine generators, the APU is dead, and the RAT is broken. Oh and you've managed to burn through quite a bit of stored energy. By the time you reach minimum charge in flight, you are already looking for a place to have the kindest, cuddliest crash possible.

Yet having a early cut out may CAUSE crashes as its a new and exciting failure point.

The real answer is the Airlines that are bricking the batteries need to either fire up the APU or connect ground power to minimize the stress on batteries not designed to keep the plane powered up for long periods.

(oh and yes, the FAA really wants you to shut down the battery just before it sets itself on fire, but if it had to pick too early and too late in this system... well its already mandated containment systems)

Topic: RE: FAA Grounds B787 Part 7
Username: rheinwaldner
Posted 2013-02-01 00:58:31 and read 19571 times.

Quoting 7BOEING7 (Reply 84):
That's the way many AD's are handled--come up with procedures or a "quick fix" hardware/software wise--get the airplanes back in the air safely--come up with the ideal solution down the road--happens a lot.

I am aware of that approach. And it is fine within some limits. But saying, the fire isn't fixed, so we just keep the fire in a safe box is far beyond those limits IMO. Thats like saying, we allow bombs in the baggage if they are just housed in a metal suitcase.

Quoting seahawk (Reply 86):
If they fix the containment, they fixed the problem. How often the batteries fail is not a safety concern.

Hopefully you never have to design systems that might cost the live of people in case of failure. And hopefully those who do, don't think like you.

The only problem you would like to have adressed seems to be the short term impact on the pocket... It will bite you the next time, that fire starts. And it will not restore public confidence. Especially after the next fire.

Topic: RE: FAA Grounds B787 Part 7
Username: Unflug
Posted 2013-02-01 01:25:40 and read 19485 times.

Quoting XT6Wagon (Reply 89):
It doesn't matter if it "shouldn't" happen, you don't want to tell the regulators that the battery that is the last line of defense against power loss to critical systems will call it a day earlier than it might otherwise have because you want to save a little money.

What do you mean by "a day earlier"? If ever used in flight the battery will not last for days. The battery normally is kept in a loaded condition and not used in flight. Quoting CM in thread #2:

The main battery is a required redundancy in the system (it provides power to the captain's instruments), but it is never used in flight during normal operations.

Quoting XT6Wagon (Reply 89):
Trust me the FAA would much rather see you say "the battery will set itself on fire to get the last joule to the flight control systems" than "the battery shuts off at 10% above absolute minimum to prevent needing to remove the battery for bench testing".

- Even in the worst case the battery does not provide power to the flight control systems.
- 10% less usable energy can be made up by using a 10% larger battery.
- On top of that, no one would prevent the system to use the second threshold only when on the ground.

Quoting XT6Wagon (Reply 89):
if you have no engine generators, the APU is dead, and the RAT is broken

In this case, the battery won't save the aircraft anyway. If the battery was to be able to replace engine power, APU and RAT it would have to be much, much larger.

Quoting XT6Wagon (Reply 89):
By the time you reach minimum charge in flight, you are already looking for a place to have the kindest, cuddliest crash possible.

Exactly.

Topic: RE: FAA Grounds B787 Part 7
Username: seahawk
Posted 2013-02-01 03:31:24 and read 19140 times.

Quoting rheinwaldner (Reply 90):
Hopefully you never have to design systems that might cost the live of people in case of failure. And hopefully those who do, don't think like you.

The only problem you would like to have adressed seems to be the short term impact on the pocket... It will bite you the next time, that fire starts. And it will not restore public confidence. Especially after the next fire.

Batteries fail. It just needs to be made sure that such a failure poses no danger to the whole system. And fixing the containment might not be an easy task, while keeping the current battery design. But any way it is unreasobale to demand that the batteries should not fail, because eventually every battery fails. It must be made sure that such a failure is easily contained.

Topic: RE: FAA Grounds B787 Part 7
Username: sphealey
Posted 2013-02-01 04:11:32 and read 19017 times.

Quoting seahawk (Reply 92):
Quoting XT6Wagon (Reply 89):
It doesn't matter if it "shouldn't" happen, you don't want to tell the regulators that the battery that is the last line of defense against power loss to critical systems will call it a day earlier than it might otherwise have because you want to save a little money.

What do you mean by "a day earlier"? If ever used in flight the battery will not last for days. The battery normally is kept in a loaded condition and not used in flight.

"Call it a day" is a colloquial phrase used in the US; it means "end of the work day", "stop working", or more generally "stop what you were doing". In this context XT6Wagon meant that the battery would shut down before it was completely exhausted. He did not mean literally '24 hours earlier'. Just a difference in language patterns.

sPh

Topic: RE: FAA Grounds B787 Part 7
Username: 2175301
Posted 2013-02-01 04:24:04 and read 18960 times.

Quoting rheinwaldner (Reply 82):

Bandaid tactics IMO.

There is not a single Airplane, Jetliner, Nuclear Power Plant, or anything in existence that is designed for absolute safety; and in fact what is agreed upon as a "safe enough" approach is often a "band-aid" tactic because there are no perfect design solutions for most issues.

So yes, this problem will in fact be fixed with some kind of "band-aid" approach.

Quoting spacecadet (Reply 83):
Unless Boeing is actively conspiring with the FAA on a way to get the 787 flying before the NTSB releases its findings and recommendations, then they're just tilting at windmills with this "solution". Either that or the rumor is baseless.

Welcome to the real world - It is quite common for the FAA to allow aircraft to fly long before the NTSB investigation is completed. In fact; I am not sure if there are any cases where the FAA waited until after the NTSB report was complete before approving some kind of change that allowed the aircraft to return to service. I believe you have a misunderstanding of the functions of the NTSB and the FAA; and their relationship.

Quoting seahawk (Reply 86):
If they fix the containment, they fixed the problem. How often the batteries fail is not a safety concern.

I am not sure of that. While a containment upgrade appears to be obvious; there may be changes to the monitoring/charging circuits even if there are no problems with the batteries themselves as roomer seems to indicate.

Quoting rheinwaldner (Reply 90):

I am aware of that approach. And it is fine within some limits. But saying, the fire isn't fixed, so we just keep the fire in a safe box is far beyond those limits IMO. Thats like saying, we allow bombs in the baggage if they are just housed in a metal suitcase.

But we do allow bombs in the cargo hold. I used to ship small explosive devices by air all the time (the operative word in this case is "small"; and of course the packaging was designed and tested to contain the detonation of a device - actually had to fully contain a device twice the size of what we were producing and shipping - in 10 out of 10 test with no damage visible to the outer box). The fact is that many things on an Aircraft can fail in such a way to release energy (including items in luggage). All that is required is that they be contained or have adequate space such that the failure/release of energy does not noticeably harm other things in the area.

The fact of the matter is that Boeing and the FAA will agree on at least a temporary fix, and later a permanent fix if needed with the understanding that some batteries will in fact fail and have thermal run away and a battery fire. LI-Ion batteries will not be found to be inherently unsafe for flight.

Have a great day,

Topic: RE: FAA Grounds B787 Part 7
Username: cornutt
Posted 2013-02-01 06:39:27 and read 18575 times.

Quoting rheinwaldner (Reply 82):
You can take cells out of order by simply applying the exact same voltage to the cell, that the cell would have if it would be disconnected. If you do that, no longer any current flows through the cell.

In other words, you need control of the charging current on a per-cell basis. That largely negates the advantage of the multiple cells.

Quoting rheinwaldner (Reply 82):
The BMS needs a memory for a lot more things anyway.

The existing BMS only has memory for maintenance purposes, if it has any at all. This is memory for a safety-critical purpose, that has to survive power cycles. You are hugely underestimating the safety implications and the certification effort.

Topic: RE: FAA Grounds B787 Part 7
Username: cornutt
Posted 2013-02-01 06:50:40 and read 18548 times.

Quoting spacecadet (Reply 83):
Unless Boeing is actively conspiring with the FAA on a way to get the 787 flying before the NTSB releases its findings and recommendations, then they're just tilting at windmills with this "solution".

Several points: (1) the NTSB is not the regulatory body, the FAA is. The NTSB has no stake in whether the aviation busines survives or not. They routinely ask for things that are clearly impractical (e.g., that fuel not catch fire in a crash). (2) As others have said, interim solutions are pretty routine for short-term resolution of ADs, and if it gets the top of the fault tree back to a good number and is acceptable to the operators, what's the diff? (3) The NTSB will probably not release its final report for several years. There is no statuatory requirement that the FAA wait on the NTSB's final report. The FAA has the authority to revise the terms of the AD at any time that it sees fit. (4) I'm really getting sick of seeing these trollish statements that say "if the 787 ever flies again, it proves that there is a conspiracy between Boeing and the FAA".

Topic: RE: FAA Grounds B787 Part 7
Username: Stitch
Posted 2013-02-01 07:38:44 and read 18397 times.

Quoting RickNRoll (Reply 81):
Why were so many batteries being locked out because they had been drained compeletly?

In many cases, it was because ground crews were using the batteries for longer than Boeing's recommended time limits.



Quoting spacecadet (Reply 83):
This fix wouldn't accomplish anything as far as getting the plane back in the air unless Boeing has some inside information from the FAA about doing and end-run around the NTSB. This solution doesn't seem to solve the NTSB's main problem at all, which is that destructive battery failures are happening way too frequently on the 787.

The NTSB's concern was that a battery fire or leaking electrolytes could damage critical systems. Yes, the NTSB would prefer that a battery never catch fire, but if wishes were horses... NiCad and lead acid batteries can catch fire, as well, even if the statistical probability is much lower than with Li-Ion.



Quoting rheinwaldner (Reply 90):
But saying, the fire isn't fixed, so we just keep the fire in a safe box is far beyond those limits IMO.

That is what the Special Conditions call for.

Topic: RE: FAA Grounds B787 Part 7
Username: Tristarsteve
Posted 2013-02-01 07:52:55 and read 18328 times.

Quoting Stitch (Reply 97):
Quoting RickNRoll (Reply 81):
Why were so many batteries being locked out because they had been drained compeletly?

In many cases, it was because ground crews were using the batteries for longer than Boeing's recommended time limits.

Do you know why?
In normal service we rarely use the Main battery. The aircraft sits on ground power all the time. Once in a while I might be on an off-pier stand, and do a real battery start, but very rarely. Its quite scary on an A320 or B767 to turn on the batteries and see a couple of lights blink on, and nothing else. Then use the batteries to start the APU, and have no indications at all until the APU Generator comes on line.

On the B767 when you shut the aircraft down fully and turn off all power, as you walk away you look back and see the nose gear park brake set light is on. It comes off the hot battery bus. OK for an overnight, but if the aircraft is there for a week, better to unscrew it!
Is there something like this on the B787 that was not seen at Seattle when they had GPU in all the time?

p.s. I have worked on the line for 30 years and changed one battery in all that time.

Topic: RE: FAA Grounds B787 Part 7
Username: PHX787
Posted 2013-02-01 08:30:29 and read 18211 times.

http://www.japantoday.com/category/n...mages-from-boeing-for-787-troubles


NH wants compensation. Whoever told me in the other threads that they didn't have a right to do this, now u can stop complaining about me.

Topic: RE: FAA Grounds B787 Part 7
Username: seahawk
Posted 2013-02-01 08:42:56 and read 18113 times.

Quoting 2175301 (Reply 94):
I am not sure of that. While a containment upgrade appears to be obvious; there may be changes to the monitoring/charging circuits even if there are no problems with the batteries themselves as roomer seems to indicate.

That seems obvious, as the battery is also a reliability concern. However the FAA has 2 points to consider, the first thing is the safety of the plane and its system in case of a violent battery failure. The second, but I hope this one has been considered from the start, is the safe operation of the plane with a failed battery. I hope they have defined expected and acceptable failure rates for those batteries. If those are exceeded it is another thing that needs to be fixed, but there might be band-aid solutions possible to keep the planes flying. (increased battery changes, battery charges only outside the plane, etc.)

Topic: RE: FAA Grounds B787 Part 7
Username: cornutt
Posted 2013-02-01 09:06:18 and read 18002 times.

Quoting Tristarsteve (Reply 98):
Is there something like this on the B787 that was not seen at Seattle when they had GPU in all the time?

That's a good question, and one that I haven't found an answer to. I'm sure that there is some kind of recommendation from Boeing on how long the airplane should be left sitting on the ground on battery power, and probably some procedures for maximizing the battery life when doing that.

The other thing that I haven't found an answer to is whether or not United is seeing the same battery life problems that JAL and ANA are. So far, I haven't found anything that says they are. If they aren't, then what is United doing different?

Topic: RE: FAA Grounds B787 Part 7
Username: AeroWesty
Posted 2013-02-01 09:14:17 and read 18215 times.

Quoting PHX787 (Reply 99):
http://www.japantoday.com/category/n...mages-from-boeing-for-787-troubles

Interesting observation from ANA's CFO in there:

"Tonomoto said ANA revenue will be eroded by about 3% for this fiscal year ending March 31 if the 787 services can’t be resumed, but that will translate to minimal impact on profit. Such losses will be gradually reduced over coming months, he said."

Even with the 787 grounded, ANA is still expecting a profit growth of 12% in the current fiscal year.

Topic: RE: FAA Grounds B787 Part 7
Username: spacecadet
Posted 2013-02-01 09:33:40 and read 18114 times.

Quoting 2175301 (Reply 94):
Welcome to the real world - It is quite common for the FAA to allow aircraft to fly long before the NTSB investigation is completed.

Name me one other case in the history of this country where the FAA grounded an entire type and then let it fly again before the cause of the problems that led to the grounding was found. Just name one. I'll wait.

Quoting cornutt (Reply 96):
Several points: (1) the NTSB is not the regulatory body, the FAA is.

See above.

Quoting Stitch (Reply 97):
The NTSB's concern was that a battery fire or leaking electrolytes could damage critical systems.

Read their statements again. More carefully this time.

[Edited 2013-02-01 09:34:34]

Topic: RE: FAA Grounds B787 Part 7
Username: Stitch
Posted 2013-02-01 09:37:35 and read 18104 times.

Quoting spacecadet (Reply 103):
Read their statements again. More carefully this time.

Yeah, they say fire on a plane is unacceptable.

Well, you can't guarantee that you'll never have a fire on a plane - heck, it happens multiple times every year in some form or another - so that statement is irrelevant as it applies to lifting the grounding and certifying a commercial airliner.

That is why the NTSB has no direct authority over groundings or certification. They're allowed to ask for the impossible, but they are not allowed to require it.

[Edited 2013-02-01 09:39:00]

Topic: RE: FAA Grounds B787 Part 7
Username: flood
Posted 2013-02-01 09:42:33 and read 18094 times.

Quoting cornutt (Reply 101):
The other thing that I haven't found an answer to is whether or not United is seeing the same battery life problems that JAL and ANA are. So far, I haven't found anything that says they are. If they aren't, then what is United doing different?

According to CBS, UA has had to replace "multiple" batteries as well:
http://www.cbsnews.com/8301-18563_16...d-airlines-replaced-787-batteries/

Topic: RE: FAA Grounds B787 Part 7
Username: Kaiarahi
Posted 2013-02-01 09:55:18 and read 17978 times.

Quoting spacecadet (Reply 103):
Quoting 2175301 (Reply 94):
Welcome to the real world - It is quite common for the FAA to allow aircraft to fly long before the NTSB investigation is completed.

Name me one other case in the history of this country where the FAA grounded an entire type and then let it fly again before the cause of the problems that led to the grounding was found.

DC10. The NTSB report wasn't completed until months after the grounding was lifted.

Topic: RE: FAA Grounds B787 Part 7
Username: JHwk
Posted 2013-02-01 10:00:32 and read 17979 times.

The idea of using a Tesla-styled architecture with commodity Li-Ion 18650 cells would work, aside from the fact that you need a brand new BMS system and have to get the system certified. The 18650s are good for 2.2Ah, and you would likely want 10% extra cells, so you would need 8x36 cells for 71Ah. You would individually fuse each cell at a minimum, which would protect against short circuits. Each 3.7V block would be roughly 7.5x3.5x3" with moderate spacing, giving you an overall dimension comparable to the existing unit and potentially smaller with moderate cooling provisions. It doesn't seem like more extensive cooling provisions are really required since the duration of charge and discharge are so short, but it would appear that you could accommodate it with minimal change.

After going through all that, you are still stuck with a more volatile chemistry.

Topic: RE: FAA Grounds B787 Part 7
Username: cornutt
Posted 2013-02-01 11:01:47 and read 17724 times.

Quoting flood (Reply 105):
According to CBS, UA has had to replace "multiple" batteries as well

Copy that. So much for that theory.

Topic: RE: FAA Grounds B787 Part 7
Username: rheinwaldner
Posted 2013-02-01 12:09:19 and read 17400 times.

Quoting cornutt (Reply 95):
In other words, you need control of the charging current on a per-cell basis. That largely negates the advantage of the multiple cells.

Do you know what the balancer does today? Nothing else. You should be more careful with foregone conclusions.

Quoting cornutt (Reply 95):
The existing BMS only has memory for maintenance purposes, if it has any at all.

Are you sure? From where do you know? You can get computer lipo chargers with balancer and unique memory settings for invidually, electronically tagged batteries for less than 100$. Don't underestimate the existing BMS.

Quoting cornutt (Reply 95):
You are hugely underestimating the safety implications and the certification effort.

How do you know? I made no statement how large I estimate the certification effort would be.

Topic: RE: FAA Grounds B787 Part 7
Username: cornutt
Posted 2013-02-01 12:40:08 and read 17224 times.

Quoting rheinwaldner (Reply 109):
Are you sure? From where do you know? You can get computer lipo chargers with balancer and unique memory settings for invidually, electronically tagged batteries for less than 100$. Don't underestimate the existing BMS.

And how much of that is FAA qualified and certified?

Quoting rheinwaldner (Reply 109):
How do you know? I made no statement how large I estimate the certification effort would be.

Your previous statement answers that question. And yes, I have a pretty good idea what the certification effort would be, at least for the software.

Topic: RE: FAA Grounds B787 Part 7
Username: alberchico
Posted 2013-02-01 12:58:10 and read 17130 times.

How much damage was caused to the aircraft that had the battery fire ? Was the damage too extensive ?

Topic: RE: FAA Grounds B787 Part 7
Username: PW100
Posted 2013-02-01 13:42:17 and read 16961 times.

Quoting tdscanuck (Reply 76):
Yes, it's hugely different. You're talking about giving the battery the ability to shut down the airplane (that's "Threshold 1" in this scenario). That's what I mean by sacrificing the airplane to save the battery. The current battery can't shut the airplane down, it will continue to power it for as long as it can.

You have much more knowledge than I have on this subject, so please bear with me as apparently I have a grave misunderstanding of things here.

If, and I repeat, IF I understand correctly, in the current set-up the BMS will shut down (brick, dead, you name it) once the battery reaches a pre-determined low voltage level and/or high discharge rate.
So if, for whatever reason, the current battery set-up reaches that low-voltage preset level, the BMS will stop battery feed and it will be taken off-line. How is that different to the scenario you just described above? I just don't understand???

I thought, but perhaps I'm way off here, that the BMS will prevent such a low-voltage condition, as that might cause cell imbalances which has the potential (. .) to trigger thermal runaway.

Quoting tdscanuck (Reply 76):
. . . On it's face, the two threshold idea is uncertifiable because you've set up, by design, a single-point failure that will take down the airplane. If the Threshold 1 "nice shutdown" activates in flight you're going to die

The ANA 787 did not crash in flames. As it's critical battery went bezerk, surely it must have been taken off line at some point in flight . . . ?

You have made it quite clear in the earlier threads that a battery fire would not shut the whole plane down; loosing a battery was supposedly a minimal risk event. The 787 always has at least four live generators while in flight. If a generator fails, or even when an engine fails (losing two generators), it still has two or even three generators providing ample power to start up the APU and bring on another two generators on line.

Even if that does not work, there is always the RAT drop that will feed emergency utilities, providing minimum power requirement to maintain controlled flight. Does the RAT provide sufficient power for APU start?

PW100

Topic: RE: FAA Grounds B787 Part 7
Username: rcair1
Posted 2013-02-01 14:11:33 and read 16831 times.

Quoting AeroWesty (Reply 36):
The war of words continues. Musk and the MIT professor Sadoway claim Boeing doesn't have the engineering to prevent the domino effect which increases the risk of a thermal runaway within the battery packs. Meanwhile, Boeing's Sinnett claims that not only do they have that engineering, they've also designed the appropriate containment to keep planes safe if thermal runaway does occur.

Where do they go from there?

To the bathroom I hope - a public pissing match is not helping anybody. It destroy credibility and reputation on both sides.

Quoting rheinwaldner (Reply 82):
The cost difference is, because the Tesla battery has much higher capacity. More than four times higher.

I was not clear - the 12K I was refering to is the quoted cost of the Tesla battery in this forum. People have said the Tesla battery cost 12-16K. That is not correct. The pre-planed purchase price from Telsa, knowing you will need to buy a battery, is 14K. The price of the battery if you brick your Tesla is 40K+. I was not comparing the price difference between the 787 battery and the Tesla battery - I was debunking the idea that the Tesla battery is only 12K.

Quoting packsonflight (Reply 77):
So you are saying that the capacity of the 787 battery is similar to a battery from a 767 and 330?

I've not see a response from Tom - so I'll make a comment which I hope is correct. What I think he was saying was that the battery capacity of the 787 is driven, not by the all electric architecture, but by the higher level of electronics/avionics.
In other words - there are more computers and such for the 787 battery to run. Those would be there even if the 787 flight controls were hydraulic.
The 787 battery is bigger than the 767 - but because of the computer/avionics load - not the electrically driven controls.

Quoting Unflug (Reply 88):
Here I don't understand your line of thought (probably for the first time). As I understood, the batteries will normally not be discharged in flight. It was stated several times that the over discharge taking the batteries out of normal operation must have occurred on the ground. Neither the first nor the second threshold should ever be reached in flight.

The key is NORMALLY. In flight, the main battery is used to run the flight control computers/avionics in the event of loss of all generators. Very unlikely- but it is there. It is the last step that keeps the computers up and running - the ship flyable. It is not normally discharged at all during flight - but it is part of the emergency systems - and I believe it cannot be MEL'd. In other words - if they loose the main battery - they land and do not take off again till fixed.

Quoting Unflug (Reply 91):
What do you mean by "a day earlier"? If ever used in flight the battery will not last for days. The battery normally is kept in a loaded condition and not used in flight. Quoting CM in thread #2:

It is used in an emergency. It needs to be there and charged for that emergency.

Quoting JHwk (Reply 107):
The idea of using a Tesla-styled architecture with commodity Li-Ion 18650 cells would work, aside from the fact that you need a brand new BMS system and have to get the system certified.

Of course they 'could' work (would is more subjective). I think the 787 architecture "could" work - so could NiCads, probably not NiMH. There are lots of things that could work - that does not make them best - and I include in that the 787 current battery design. They may change it - whether forced or not. But - no solution is perfect.

Quoting JHwk (Reply 107):
After going through all that, you are still stuck with a more volatile chemistry

And you'd have a certified containment system - just like the current one.

Topic: RE: FAA Grounds B787 Part 7
Username: 7BOEING7
Posted 2013-02-01 15:07:50 and read 16611 times.

Quoting rcair1 (Reply 113):
I've not see a response from Tom - so I'll make a comment which I hope is correct. What I think he was saying was that the battery capacity of the 787 is driven, not by the all electric architecture, but by the higher level of electronics/avionics.
.

Let's just talk about the Main battery and assume we MEL'd the APU battery. If you lose all 4 engine generators, can't start the APU and the RAT fails the MAIN battery will provide power to the Captain's essential flight instruments just like the 777. He'll know which way is up/down, what altitude he's at and what speed he's going and a few other things but if he's not on the ground in about 30 minutes +/- (depending on battery life) he better be able to see where he's going because he will lose that. I'm guessing this doesn't take much more power than the same setup in the 777--it's a very small display.
The other use for the MAIN battery is as backup power for the electric brakes which would be why it would have to have more power--if it does.

Quoting rcair1 (Reply 113):
In other words - there are more computers and such for the 787 battery to run. Those would be there even if the 787 flight controls were hydraulic.
The 787 battery is bigger than the 767 - but because of the computer/avionics load - not the electrically driven controls.

It's fly-by-wire but the controls are still hydraulically powered. The electronic part are the 3 PMG's which power the flight control computers. If those all fail temporary batteries takeover until another power source powers the 28VDC system which again if you've lost everything else is the Main battery--but again it won't last forever.In this case we're talking about both engines falling off or seizing up (4 generators/3 pmgs), an APU that doesn't start and a RAT that doesn't drop--it's not your day.

Topic: RE: FAA Grounds B787 Part 7
Username: Tristarsteve
Posted 2013-02-01 15:08:43 and read 16623 times.

Quoting rcair1 (Reply 113):
the main battery is used to run the flight control computers/

Well actually the flight control computors have their own separate batteries (two of them) that are dedicated to that function. B777 is the same.

Topic: RE: FAA Grounds B787 Part 7
Username: phxa340
Posted 2013-02-01 16:18:44 and read 16417 times.

Finally some good news .... if they are making progress one can assume they finally might have discovered a root cause.

http://www.chicagotribune.com/busine...bre91017e-20130201,0,2402767.story

Topic: RE: FAA Grounds B787 Part 7
Username: 7BOEING7
Posted 2013-02-01 16:25:48 and read 16342 times.

Quoting phxa340 (Reply 116):
Finally some good news .... if they are making progress one can assume they finally might have discovered a root cause.

Or, unfortunately, that they are just ruling things out.

Topic: RE: FAA Grounds B787 Part 7
Username: Stitch
Posted 2013-02-01 16:40:39 and read 16317 times.

Quoting 7BOEING7 (Reply 117):
Or, unfortunately, that they are just ruling things out.

I would think ruling some things out would be a positive development, as it narrows the fault analysis tree.

Topic: RE: FAA Grounds B787 Part 7
Username: RickNRoll
Posted 2013-02-01 17:16:45 and read 16158 times.

Quoting phxa340 (Reply 116):

Finally some good news .... if they are making progress one can assume they finally might have discovered a root cause.

They didn't actually claim anything, just that they are doing something, which people always like to know.

Topic: RE: FAA Grounds B787 Part 7
Username: ComeAndGo
Posted 2013-02-01 17:19:29 and read 16174 times.

That Article has zero information. Oh yeah, we're getting older.

Topic: RE: FAA Grounds B787 Part 7
Username: par13del
Posted 2013-02-01 17:23:33 and read 16182 times.

Quoting PW100 (Reply 112):
So if, for whatever reason, the current battery set-up reaches that low-voltage preset level, the BMS will stop battery feed and it will be taken off-line. How is that different to the scenario you just described above? I just don't understand???

My understanding is as follows:
In the current situation the battery "bricks" based on a pre-set of conditions, there is no return from that, the battery has to be removed and returned to the OEM for repair. Fault tree = battery no brick continue operation, battery brick remove.

Threshold 1 is now a recoverable situation, there is no longer the sure knowledge that the battery must be removed, so we now have to verify and assertain whether the indication is valid, a faulty sensor, or software glitch, an entire new fault tree must be designed to investigate the issue and determine whether it is safe to put the battery back online. One can now question the battery.

Quoting PW100 (Reply 112):
I thought, but perhaps I'm way off here, that the BMS will prevent such a low-voltage condition, as that might cause cell imbalances which has the potential (. .) to trigger thermal runaway.

Not prevent it but when it dectects a low voltage or high discharge rate the BMS shuts down the battery, bricks it so it has to be removed.

Topic: RE: FAA Grounds B787 Part 7
Username: NAV20
Posted 2013-02-01 17:28:16 and read 16237 times.

Quoting 7BOEING7 (Reply 117):
Or, unfortunately, that they are just ruling things out.

According to the link phxa340 provided, the actual quote was:-

"Our investigators are moving swiftly and we are making progress," spokeswoman Kelly Nantel told Reuters after the U.S. safety board issued a seventh update on the investigation.'

In 'officialese,' expressions like 'moving swiftly' are rarely if ever employed. As an ex-bureaucrat that strongly suggests to me that the investigation is moving in a more 'targeted' way than previously.

Also, the latest NTSB press release says:-

"Next week, the NTSB battery testing team will initiate a non-invasive "soft short" test of all cells of the exemplar battery. This test will reveal the presence of any high resistance, small or "soft" shorts within a cell. Also, an NTSB investigator will travel to France with the battery contactor from the JAL event battery, for examination at the manufacturer. The battery contactor connects a wiring bundle from the airplane to the battery."

http://www.ntsb.gov/news/2013/130201b.html

Perhaps the more knowledgeable posters on here can shed light on the part 'battery contactors' play in electrical circuits, and in what sort of circumstances they could contribute to battery trouble?

Topic: RE: FAA Grounds B787 Part 7
Username: phxa340
Posted 2013-02-01 17:29:11 and read 16228 times.

Quoting ComeAndGo (Reply 120):
That Article has zero information.

Yea it does ... in the previous 6 announcements the NTSB sounded vague and directionless, at least now they sound a little more confident, that in itself could mean something .... or nothing.

Topic: RE: FAA Grounds B787 Part 7
Username: ComeAndGo
Posted 2013-02-01 21:25:50 and read 15760 times.

Quoting NAV20 (Reply 122):
In 'officialese,' expressions like 'moving swiftly' are rarely if ever employed. As an ex-bureaucrat that strongly suggests to me that the investigation is moving in a more 'targeted' way than previously.

I can watch my hair grow longer.

I think it might have something to do with the secretary of transportation stepping down.

Topic: RE: FAA Grounds B787 Part 7
Username: sweair
Posted 2013-02-02 00:20:58 and read 15446 times.

How big would a fuel cell have to be to replace the batteries in an aircraft? One for the APU and one or two instead of batteries? I would use jet fuel instead of hydrogen for fuel. Could the waste heat be of use in the aircraft?

Topic: RE: FAA Grounds B787 Part 7
Username: sweair
Posted 2013-02-02 01:54:31 and read 15303 times.

http://www.aviationweek.com/Article....e-xml/awx_09_07_2012_p0-493403.xml

Quite large it seems, maybe with time these will go down in size and weight.

Topic: RE: FAA Grounds B787 Part 7
Username: fcogafa
Posted 2013-02-02 02:18:36 and read 15483 times.

Flightglobal is running an article titled

'Air India RFP proof of solid 787 demand despite investigations: lessor'

but it is behind a log in....

Topic: RE: FAA Grounds B787 Part 7
Username: Chipmunk2307
Posted 2013-02-02 02:20:15 and read 15433 times.

Hello All, long time reader of this web site and first time poster.

Apologies if this might have been questioned previously as I only check in once a day and may have missed this in this very long discussion thread.

What my query was, if all of the operators of the 787 have had to replace batteries outside of the "normal" maintenance schedule, and given the current circumstances for grounding, would this make Boeing liable in anyway, of being negligent for not reporting this to the relevant supervisory authorities?

If the FAA/NTSB is of the opinion that the aircraft should be grounded (which has been done), should the manufacturer also be responsible for reporting abnormal maintenance issues to the appropriate authority?

I realise that there is a lot of passion within this thread and I'm certainly not wanting to suggest that a party has been deliberately or unknowingly negligent, but shouldn't abnormal issues be pro-actively be reported before an AD be issued? Both Boeing and Airbus get real time data from a lot of their aircraft as well as regular updated information from their clients so they would know what is happening. So why not act sooner, perhaps?

Thanks in advance to the usual contributors who are well informed and work in the industry.

Cheers
CMB

P.S Much respect to Ferpe, CM, Stich, and TdsCanuck for your inputs into the A350XWB Prototypes forum, an interesting read on how a new plane is born.

Topic: RE: FAA Grounds B787 Part 7
Username: rwessel
Posted 2013-02-02 03:26:49 and read 15222 times.

Quoting sweair (Reply 125):
How big would a fuel cell have to be to replace the batteries in an aircraft? One for the APU and one or two instead of batteries? I would use jet fuel instead of hydrogen for fuel. Could the waste heat be of use in the aircraft?

Mostly reposting what I said in another thread:

Fuel cells are not great replacements for emergency batteries.

If you had H2/O2 powered fuel cells, you'd need enough power to open the valves to the tanks, assuming the tanks were pressurized. You'd also need some regulation, but that can be done mostly mechanically.

You'd also be looking a reasonable lag before these came up to full power, which they won't do until the catalyst gets warm enough.

If you're running Jet-A and air into your fuel cell, you'll need to heat up the reformulator first, so you can decomposed the Jet-A, which will take both time and a fair bit of power.

A battery will supply power *right now*.

A fuel cell might be a reasonable alternative to an APU, but *not* the batteries. But the maturity of such a fuel cell is questionable, especially at the power levels that many APUs generate – the 787’s APU, for example, is a small turbine (~750shp) driving a pair of 225KVA generators. That’s somewhat exotic territory for fuel cells.

Also, fuel cells don't produce all that much power (watts) for a given weight of fuel cell. They are useful because they can convert fuel into (electrical) energy (watt-seconds or Joules) with considerable efficiency, so the total mass of your fuel+fuel-cell system can be much, much lower than trying to same number of Joules out of a battery. But it will delivery those Joules much more slowly than a battery (IOW, fewer watts).

Batteries are much better for high, but relatively short, loads.

Topic: RE: FAA Grounds B787 Part 7
Username: flyingbird
Posted 2013-02-02 03:59:49 and read 15203 times.

From Flightradar24 Facebook

Air India have been flying with 2 Boeing 787 Dreamliner today!
VT-ANI as AIC553 http://www.flightradar24.com/data/airplanes/vt-ani
VT-ANL as AIC555 http://www.flightradar24.com/data/airplanes/vt-anl

Topic: RE: FAA Grounds B787 Part 7
Username: sweair
Posted 2013-02-02 04:46:29 and read 14978 times.

Quoting flyingbird (Reply 130):

Is that not a bug in flightradar showing the wrong model?

Topic: RE: FAA Grounds B787 Part 7
Username: aloges
Posted 2013-02-02 05:04:54 and read 14961 times.

Quoting sweair (Reply 131):
Is that not a bug in flightradar showing the wrong model?

Probably not, there was also VT-ANK operating AIC551 today. FR24.com says it went to VTZ (Visakhapatnam), airindia.com says it went to BOM just like 553 and 555. However, none of the flights can be found in Air India's downloadable pdf timetable or on the airport websites of DEL and BOM. The flight number also don't bear a resemblance to Air India's regular numbers for flights between those cities.

Test flights? Leprechauns in the database?   

Topic: RE: FAA Grounds B787 Part 7
Username: Stitch
Posted 2013-02-02 05:26:09 and read 14860 times.

Quoting Chipmunk2307 (Reply 128):
What my query was, if all of the operators of the 787 have had to replace batteries outside of the "normal" maintenance schedule, and given the current circumstances for grounding, would this make Boeing liable in anyway, of being negligent for not reporting this to the relevant supervisory authorities?

The batteries needed replacement because the safety features on them were operating as designed. Therefore, there should be no liability involved.


Quoting Chipmunk2307 (Reply 128):
If the FAA/NTSB is of the opinion that the aircraft should be grounded (which has been done), should the manufacturer also be responsible for reporting abnormal maintenance issues to the appropriate authority?

They were abnormal in terms of the number of events, but the events were caused by the safety features of the battery operating as designed. Reports imply the majority of these events were triggered by ground crew not properly managing their time and running the batteries longer than Boeing specified. Reports state that such issues are not required to be reported as they are not safety-related.

Topic: RE: FAA Grounds B787 Part 7
Username: Aesma
Posted 2013-02-02 11:10:40 and read 14183 times.

About Li-ion batteries in aircraft I mentioned the Antares 20E before, let me now mention the Antares DLR-H2 test-bed for fuel cell powered flight :

http://hfr-rehost.net/http://www.dlr.de/dlr/en/Portaldata/1/Resources/bilder/portal/portal_2012_4/Antares.jpg

As you can see it's quite bulky, with one pod for the cell and one pod for the H2 tank. It gives 700Km of range. The Antares H3 is now in development, with 4 pods, and an expected range of 6000Km, endurance of 50h, probably a drone ultimately.

Topic: RE: FAA Grounds B787 Part 7
Username: sweair
Posted 2013-02-02 11:16:42 and read 14148 times.

A fuel cell would not be shut off it would provide current constantly during flight. Maybe batteries would still be needed as a backup if the fuel cell/s fail?

Topic: RE: FAA Grounds B787 Part 7
Username: KELPkid
Posted 2013-02-02 11:37:44 and read 14099 times.

Quoting ComeAndGo (Reply 124):
I can watch my hair grow longer. I think it might have something to do with the secretary of transportation stepping down.

Why?

The NTSB is a separate entity....which only has an advisory role to the FAA.

Although the FAA falls under DOT, unless the FAA chief gets replaced, I seriously doubt they will be rescinding the emergency AD anytime soon. If they do, someone at the FAA will be eating some serious crow  

Topic: RE: FAA Grounds B787 Part 7
Username: cornutt
Posted 2013-02-02 14:15:16 and read 13762 times.

Full text of the 1 February NTSB press release here:

http://www.ntsb.gov/news/2013/130201b.html

The one thing that jumps out at me is that they are going to be examining the battery contactor. I haven't heard anything previously about the contactor possibly having a role. I guess they're looking at the possibility of the contactor creating a short across the battery somehow.

If you look down near the end of the press release, there is a URL to another page that has some interesting photos and presentations.

Topic: RE: FAA Grounds B787 Part 7
Username: flyingbird
Posted 2013-02-02 17:23:55 and read 13284 times.

Quoting sweair (Reply 131):
Is that not a bug in flightradar showing the wrong model?

Flightradar24 have a static database of route numbers that can sometimes be incorrect. But if an aircraft transponder ModeS code is shown on map that it's flying (in this case 800732 and 8005F2), then it's flying. It's almost impossible to generate such error.

According to FR24 Facebook comments VT-AND will be flown to BOM soon as well.

Topic: RE: FAA Grounds B787 Part 7
Username: NAV20
Posted 2013-02-02 18:03:50 and read 13184 times.

Quoting cornutt (Reply 137):
I haven't heard anything previously about the contactor possibly having a role. I guess they're looking at the possibility of the contactor creating a short across the battery somehow.

It's OK, cornutt, not offended if you missed this, there are lots of posts on here!  :-

Quoting NAV20 (Reply 122):
Also, the latest NTSB press release says:-

"Next week, the NTSB battery testing team will initiate a non-invasive "soft short" test of all cells of the exemplar battery. This test will reveal the presence of any high resistance, small or "soft" shorts within a cell. Also, an NTSB investigator will travel to France with the battery contactor from the JAL event battery, for examination at the manufacturer. The battery contactor connects a wiring bundle from the airplane to the battery."

http://www.ntsb.gov/news/2013/130201b.html

Perhaps the more knowledgeable posters on here can shed light on the part 'battery contactors' play in electrical circuits, and in what sort of circumstances they could contribute to battery trouble?

Instinct only - but this does 'suggest' that maybe they're narrowing down the possibilities a bit?

Topic: RE: FAA Grounds B787 Part 7
Username: PHX787
Posted 2013-02-02 19:17:08 and read 13032 times.

Quoting NAV20 (Reply 139):
Instinct only - but this does 'suggest' that maybe they're narrowing down the possibilities a bit?

I sure hope that's the case, if they were instead broadening the horizons of possibilities, I would be groaning so loud right now, because it only means a longer grounding period.

Topic: RE: FAA Grounds B787 Part 7
Username: NAV20
Posted 2013-02-02 19:48:59 and read 12991 times.

Quoting PHX787 (Reply 140):
if they were instead broadening the horizons of possibilities, I would be groaning so loud right now

Agreed, PXH787, that's the other possible (and much less hopeful) scenario. I suppose I'm clinging to the "moving swiftly.....making progress" NTSB announcement that accompanied the altered approach. Just maybe they're finding evidence that it could well be another part of the system, not the batteries, that is causing the problem.

One thing I don't understand is why they've grounded the aeroplane entirely. I'm sure that the Boeing test pilots have enough faith in the aeroplane to take them up (over water if necessary) and carry out some 'investigations' in flight, with 'everything hot.' Might give much better information than just testing everything in the laboratory or at 'ground idle'?

[Edited 2013-02-02 19:49:51]

Topic: RE: FAA Grounds B787 Part 7
Username: liquidair
Posted 2013-02-02 19:50:39 and read 12979 times.

Lithium is such a bitch! So emotionally stable... but thermally.... Ouch!

Topic: RE: FAA Grounds B787 Part 7
Username: blrsea
Posted 2013-02-02 20:53:43 and read 12908 times.

A boeing engineer blames the outsourcing strategy for the numerous electical failures on the 787. Goes as far as to say that more problems with the electical panels can be expected!

Boeing 787’s problems blamed on outsourcing, lack of oversight

Quote:
...
Boeing’s 787 Dreamliner has suffered numerous electrical system flaws beyond the battery problems that led to its current grounding, according to engineers with knowledge of the situation.

Company engineers blame the 787’s outsourced supply chain, saying that poor quality components are coming from subcontractors that have operated largely out of Boeing’s view.

“The risk to the company is not this battery, even though this is really bad right now,” said one 787 electrical engineer, who asked not to be identified. “The real problem is the power panels.”

Unlike earlier Boeing jets, he said, the innards of the 787 power distribution panels — which control the flow of electricity to the plane’s many systems — are “like Radio Shack” with parts that are “cheap, plastic and prone to failure.”
...
...
Following that in-flight problem, United in late December reported continuing “sporadic issues with our 787 generators and power distribution panels.”

Sinnett said last month that, “While we don’t have the specific exact root cause, the issues have all been traced back to a single lot of (circuit) boards manufactured at one time by a subtier supplier.”
...
...
Traditionally, he said, Boeing’s in-house experts created detailed specifications for every part of the plane made by suppliers, and had the in-house technical capability to closely monitor whether the work came up to spec.

“They needed complete knowledge of what was going on,” said Hart-Smith. “I warned that if they outsourced too much work, the day would eventually come when there wouldn’t be enough in-house capability to even write the specs.”
...
...
The Boeing engineer with direct knowledge of the electrical systems is not optimistic.

“We talk to supplier management all the time,” he said. “These parts are such bad quality.”

To catch and eliminate minor system faults that he blames on persistent problems with the quality of parts, Boeing has routinely been flying nine or 10 pre-delivery flights of each 787 before it hands the plane over to a customer, he said.

On its other jets, Boeing typically makes just two pre-delivery flights, one by Boeing, then one by the customer.
...
...
He said the company has been to focused on individual, narrow fixes.

“We have not done a real redesign,” he said. “We should be examining the entire electrical system.”

Topic: RE: FAA Grounds B787 Part 7
Username: kanban
Posted 2013-02-02 21:06:47 and read 12822 times.

Quoting blrsea (Reply 143):

A boeing engineer

nice cherry picking.. and biased extraction. one or two boeing engineers not connected with the program and pissed off about the union negotiations really do not have a lot of creditability.. There are always some within a large company who being either more risk taking or less risk taking than the plan, love to go to the press and complain. It's their right, however treat them with a grain of salt. A company is not run as a democracy with everyone in agreement.

Topic: RE: FAA Grounds B787 Part 7
Username: blrsea
Posted 2013-02-02 21:13:17 and read 12799 times.

Quoting kanban (Reply 144):
nice cherry picking.. and biased extraction.

Did you even read the article before accusing me of cherry picking and biased extraction? Can you please point out the other side of the same extracts which the author has posted in the article that I missed??

As regards to your comment regarding engineers not associated with the program, read the article. Even the extract that I posted talks about the electical engineer who know the 787 system.

Dude, why do you see agendas when none exists? I am not dissing any company in here. I have made relatively few posts on these threads, and most have been posting articles from Seattle times. jeez, some people see boeing-baters behind every post. Grow up!  

Topic: RE: FAA Grounds B787 Part 7
Username: cornutt
Posted 2013-02-02 21:17:22 and read 12786 times.

Quoting blrsea (Reply 143):
A boeing engineer

It wasn't me!   

Quoting NAV20 (Reply 141):
'm sure that the Boeing test pilots have enough faith in the aeroplane to take them up (over water if necessary) and carry out some 'investigations' in flight, with 'everything hot.' Might give much better information than just testing everything in the laboratory or at 'ground idle'?

That may be coming. First they need a working theory on what is actually happening, so that they can design a test flight with the proper flight profile and instrumentation. It sounds like they may be zeroing in on that.

BTW: any battery guys here -- what do they mean by a "soft short"?

Topic: RE: FAA Grounds B787 Part 7
Username: SonomaFlyer
Posted 2013-02-02 21:48:24 and read 12714 times.

The article makes sense given the issues and the fact Boeing elected to dole out the work - including design - to subcontractors. You lose quality control that way and it can bite you in the ass down the road.

The problems UA faced sound like issues with the panels. IF the panels are not working as specified, the ripple effect of over charge/under charge or other types of spikes can have a negative effect on the entire electrical system. That can include knocking generators offline and affecting the batteries.

Hopefully the design of the panels themselves are sound and its a matter of quality control in part selection and assembly. If there is a flaw in the design of the panel, that will take a while to redesign/test/certify.

Topic: RE: FAA Grounds B787 Part 7
Username: Aesma
Posted 2013-02-02 23:15:10 and read 12555 times.

Quoting liquidair (Reply 142):
Lithium is such a bitch! So emotionally stable... but thermally.... Ouch!

Made me laugh  !

Quoting NAV20 (Reply 141):
One thing I don't understand is why they've grounded the aeroplane entirely. I'm sure that the Boeing test pilots have enough faith in the aeroplane to take them up (over water if necessary) and carry out some 'investigations' in flight, with 'everything hot.' Might give much better information than just testing everything in the laboratory or at 'ground idle'?

My guess is that Boeing was already doing that the entire time 787s were in the air but that didn't work. And that quote seems to confirm my idea :

Quoting blrsea (Reply 143):
To catch and eliminate minor system faults that he blames on persistent problems with the quality of parts, Boeing has routinely been flying nine or 10 pre-delivery flights of each 787 before it hands the plane over to a customer, he said.

Topic: RE: FAA Grounds B787 Part 7
Username: RickNRoll
Posted 2013-02-03 02:31:08 and read 12068 times.

Quoting Stitch (Reply 133):
The batteries needed replacement because the safety features on them were operating as designed. Therefore, there should be no liability involved.

Do we know the actual numbers, or a rough ratio. As I understand it, one of the problems was the batteries being drained to the point that they locked themselves. However, from articles we have seen here, that was only one of the reasons mentioned for them being replaced. IIRC, some of them were faulty.

Topic: RE: FAA Grounds B787 Part 7
Username: kmz
Posted 2013-02-03 05:01:17 and read 11693 times.

Quoting blrsea (Reply 143):
Boeing 787’s problems blamed on outsourcing, lack of oversight
Quote:
" Traditionally, he said, Boeing’s in-house experts created detailed specifications for every part of the plane made by suppliers, and had the in-house technical capability to closely monitor whether the work came up to spec.

“They needed complete knowledge of what was going on,” said Hart-Smith. “I warned that if they outsourced too much work, the day would eventually come when there wouldn’t be enough in-house capability to even write the specs.”

I also think that the point made in the article about outsourcing detailed specifications of dedicated systems is critical. You come to the point where you have no clue what the supplier is doing. And what is even worse, you will have a hard time arguing with a supplier when he comes to you and says ' I have to do it this way since it is not feasible this way'. You can only trust him. This makes innovation hard. I think that Airbus is not really different here. I have seen specs of systems where the cover page was form Airbus and the rest from the supplier (Please don't ask me about details).

Topic: RE: FAA Grounds B787 Part 7
Username: PITingres
Posted 2013-02-03 06:45:53 and read 11429 times.

Quoting blrsea (Reply 143):
(article extract) To catch and eliminate minor system faults that he blames on persistent problems with the quality of parts, Boeing has routinely been flying nine or 10 pre-delivery flights of each 787 before it hands the plane over to a customer, he said.

Problem is, I don't believe that is accurate. Nyc787's blog lists the number of test flights before delivery; unfortunately, the table doesn't carry that number after delivery, but if I'm recalling right, having more than 4 or 5 test flights was unusual. Not unheard of, and there were one or two planes that needed 9+ pre-delivery flights, but those were exceptions -- and in at least one case (Qatar) there was reason to believe that the extra flights had nothing to do with the power panels.

Topic: RE: FAA Grounds B787 Part 7
Username: trex8
Posted 2013-02-03 06:51:12 and read 11730 times.

Quoting RickNRoll (Reply 149):
Do we know the actual numbers, or a rough ratio. As I understand it, one of the problems was the batteries being drained to the point that they locked themselves. However, from articles we have seen here, that was only one of the reasons mentioned for them being replaced. IIRC, some of them were faulty.

per the Seattle Times article
http://seattletimes.com/html/busines...020241385_787deadbatteriesxml.html

“We have had at least 100, possibly approaching 150, bad batteries so far,” the person said. “It’s common.”

Most of the batteries were returned because they had run down so far that a low-voltage cutout was activated.

However, she acknowledged that there has been a series of problems and listed “the top three reasons for Boeing returning batteries” as batteries running down, being improperly disconnected, or exceeding their expiration date.

Topic: RE: FAA Grounds B787 Part 7
Username: sweair
Posted 2013-02-03 07:03:47 and read 11630 times.

A lot of BS in these threads, A and B can hardly be experts on every part in their products, it has never been this way and will never be this way, they contract someone who has this expertise and know everything about the product. A+B only integrate these parts into their products according to the specs they asked for.

Topic: RE: FAA Grounds B787 Part 7
Username: rcair1
Posted 2013-02-03 07:27:00 and read 11534 times.

Quoting blrsea (Reply 143):
nlike earlier Boeing jets, he said, the innards of the 787 power distribution panels — which control the flow of electricity to the plane’s many systems — are “like Radio Shack” with parts that are “cheap, plastic and prone to failure.”

Oh come on - professional engineers involved in a system do not talk like this. Disgruntled ones, ones looking for attention, may. I was an engineer in RnD and Manf for 25 years - still an active engineer - just not doing that. I've worked on far too many teams, on products both internally and externally sourced, for me to buy this statement as anything but bluster or overstatement. We may gripe to each other, but we don't go to the press with statements like this on products that are the lifeblood of our jobs. Of course - I didn't have a union protecting my back either. I would have been fired for this.

Quoting SonomaFlyer (Reply 147):
You lose quality control that way and it can bite you in the ass down the road.

Sorry - a long worn myth that is tired and useless. No company - NO COMPANY - makes all the components, motors, systems, sub-assemblies in relatively simple systems - and certainly not in complex ones like an aircraft. Sure - you _can_ have a quality problem with a outsourced sub-assembly. You can _also_ have a problem with an in-sourced one. Who designed the wing-body attachment systems on the 787 that failed testing - probably Boeing. Who designed the cracked 'legs' in the A380 wing - probably Airbus. Who designed the process that failed in RR engines on the 380 - RR.

I oversaw the quality of a product line that went from in-house design and production in the US (downstairs from my office) to ODM design and production in Taiwan. Where there problems - yes - but no more than on our own production line (I know - I was on 24 hr call for production quality issues in both cases - trust me - I worked very hard to make sure the systems worked). Did I enjoy shifting the product/production. NO. I would have much preferred to keep in in-house - it was more familiar and more comfortable. It was more convenient. Was it easier? No. Parts of my job got easier, parts harder. It was different. I also realized our competition was eating our lunch - and if we did not change it really did not matter if I kept the job in-house - we'd shut down the business within a year because there was not enough money coming in to pay my salary. BTW - 12-15 years later - the piece of that product line that is still 'in-house' is the S/W that ships with it - and frankly - it is crap. The designers have lost touch with the target/purpose. The h/w is fine - and you can buy 3rd party s/w that runs it nicely (better).

The one 'safety' related issue I remember for a product was a fire issue in a stepper motor that did not get de-energized appropriately. The device the motor was in was completely outsourced (built by Canon - that well known low quality OEM that makes crap - yeah right - Canon builds quality products). The f/w that caused the failure was WRITTEN IN HOUSE. When we saw the fires, some initially jumped to a problem in the OEM part. They were wrong. The good ones focused on the issue and determined what was wrong - and fixed it. A line of code commented out during testing and forgot to put back in.

Outsourcing - and particularly shifting from inhouse to outsource can cause issues - it is a different process and requires different tools and skills. It can delay schedules - and it is not the panacea management may claim or wish. (BTW - I've never been a manager...).A large shift to outsourcing can cause delay and I think it did in the 787 case. But the "everything somebody else builds must be cr*p is just silly." As a design engineer you trust other engineer's work daily - doesn't matter if they are in your building or one down the street or across the world.

Topic: RE: FAA Grounds B787 Part 7
Username: SonomaFlyer
Posted 2013-02-03 07:35:35 and read 11480 times.

Quoting rcair1 (Reply 154):
Outsourcing - and particularly shifting from inhouse to outsource can cause issues - it is a different process and requires different tools and skills. It can delay schedules - and it is not the panacea management may claim or wish. (BTW - I've never been a manager...).A large shift to outsourcing can cause delay and I think it did in the 787 case. But the "everything somebody else builds must be cr*p is just silly." As a design engineer you trust other engineer's work daily - doesn't matter if they are in your building or one down the street or across the world.

My point is that Boeing has never outsourced to this degree. The fact someone else designs and builds a part to a spec isn't terrible in itself but does mean Boeing must be vigilant to ensure the quality of the components and competence in assembly.

When it comes to the panels, we know there was a FoD issue which caused some design changes. However, one would assume the remainder of the panel design and electrical system in general passed all of Boeing's quality control and operation checks.

I guess the lesson is keep a sharper eye on your subs or design in-house and have someone else build your design?

Topic: RE: FAA Grounds B787 Part 7
Username: cornutt
Posted 2013-02-03 07:57:33 and read 11426 times.

Quoting rcair1 (Reply 154):
Sorry - a long worn myth that is tired and useless. No company - NO COMPANY - makes all the components, motors, systems, sub-assemblies in relatively simple systems - and certainly not in complex ones like an aircraft.

Reminds me of the old saying about Ford's River Rouge plant in Michigan -- that trees and rocks went in one end, and cars came out the other end. Of course, no auto manufacturer comes anywhere close to that these days.

Outsourcing is definitely a devil-in-the-details thing. In military projects it's pretty common to sub out a lot of subsystems, and let the subs write their detailed specs to system-level requirements provided by the prime. However, the prime (if they're smart) participates significantly in the sub's spec-writing process, and has the final say over the specs produced. It's the prime's job to understand all of the ways in which subsystems can interact and influence one another, and not all of those interactions are things that will be found in an interface control document.

When you sub something out, you are basically renting the sub's expertise. That can be a lot more cost-effective than maintaining the expertise in-house, but you have to understand what you're getting. I worked on one project where software was subbed to a contractor that had no previous experience in aerospace, and the work eventually had to be pulled back in house because the sub just fundamentally didn't "get it". They would do a good job if they were told exactly what to do, but the level of supervision required (we were having to keep people TDY at their site for weeks at a time) meant it was more cost-effective to do the work in house, even though the sub's rates were pretty low compared to ours.

Topic: RE: FAA Grounds B787 Part 7
Username: LTBEWR
Posted 2013-02-03 08:52:52 and read 11184 times.

Didn't the sub-contracting of the batteries and related electrical system components come from companies that did military aircraft sub-contrctors? Let us not forget the financial and political factors in outsourcing by Boeing of significant parts of the 787 to Japanese companies including the batteries sourced from there to help sales of the 787 to Japanese carriers.

I would also suspect that the Japanese companies involved with the battery problems are per their culture, with their peers, as well as to their country, deeply ashamed of these problems and will be very willing to make it right, even if at great cost.

Topic: RE: FAA Grounds B787 Part 7
Username: 7BOEING7
Posted 2013-02-03 10:33:56 and read 10887 times.

From Dominic Gates Seattle Times article:

"To catch and eliminate minor system faults that he blames on persistent problems with the quality of parts, Boeing has routinely been flying nine or 10 pre-delivery flights of each 787 before it hands the plane over to a customer, he said."


The press as usual tends to take statements without checking the facts. Although I can't speak to the earlier deliveries the "facts" about the last 16 looks like this:

Airplanes 16

Boeing flights 24 (1.5 flts/airpalne)

Customer flights 35 (2.2 flts/airplane)

Average flights 3.7 (take out the 8 flt outrider and you have 3.4 --which is about what the 737 numbers have been historically)

2 flts--3 3 flt--5 4 flts--5 5 flts--2 8 flts--1

The earlier airplanes probably took more flights and there may have been a couple that needed 7 or 8. All the early airplanes also needed an extra FAA flight as they were built before the production ticket was blessed, but to say they routinely took 9 or 10 flights is pure b******t. Dominic needs to check his facts from the engineer that obviously has an ax to grind.

Historically all Boeing airplanes nedd betweeen 2.5 and 3.5 flights before they deliver. The last 787 deliveries are right there with improvement to come.


[Edited 2013-02-03 10:36:21]

[Edited 2013-02-03 10:39:39]

Topic: RE: FAA Grounds B787 Part 7
Username: TheSultanOfWing
Posted 2013-02-03 10:43:17 and read 10823 times.

You wonder how all this affects the "break-even" number for the 787 program......

FH.

Topic: RE: FAA Grounds B787 Part 7
Username: ikramerica
Posted 2013-02-03 11:14:17 and read 10698 times.

Quoting flyingbird (Reply 138):
Flightradar24 have a static database of route numbers that can sometimes be incorrect. But if an aircraft transponder ModeS code is shown on map that it's flying (in this case 800732 and 8005F2), then it's flying. It's almost impossible to generate such error.

According to FR24 Facebook comments VT-AND will be flown to BOM soon as well.

India can allow moving the aircraft around domestically at their discretion.

Quoting NAV20 (Reply 141):
One thing I don't understand is why they've grounded the aeroplane entirely. I'm sure that the Boeing test pilots have enough faith in the aeroplane to take them up (over water if necessary) and carry out some 'investigations' in flight, with 'everything hot.' Might give much better information than just testing everything in the laboratory or at 'ground idle'?

It's what I've been asserting. The complete grounding is not fact based. It's fear based and CYA related. There is no reason that Boeing shouldn't be allowed to fly test aircraft or pre-delivery aircraft. They would be without passengers other than engineers, constantly near diversion points, would not risk the ETOPS rating of a carrier, etc.

Everyone knows I think the commercial grounding is overdone considering the lack of grounding or aircraft after deadly and more mysterious incidents, but at minimum, the complete grounding that even covers Boeing is beyond ridiculous and can't readily be explained by anyone in charge.

Topic: RE: FAA Grounds B787 Part 7
Username: sweair
Posted 2013-02-03 11:27:06 and read 10629 times.

AI flying around must be sort of an show of confidence in the 788 as they have been some of the most vocal against it. The test flight grounding is a step too far imo too, emotional decision making is seldom a good base.

Topic: RE: FAA Grounds B787 Part 7
Username: packsonflight
Posted 2013-02-03 11:44:02 and read 10555 times.

Quoting SonomaFlyer (Reply 155):
When it comes to the panels, we know there was a FoD issue which caused some design changes. However, one would assume the remainder of the panel design and electrical system in general passed all of Boeing's quality control and operation checks.

How can you state it was a FOD. Is that suddenly a fact now? Boeing only said possible FOD if I recall correctly.

Why the extensive rework of the panel if it only was a simple FOD issue? never made any sense to me. More like PR spin to play down issues with the design and behaviour of the system.

Topic: RE: FAA Grounds B787 Part 7
Username: Stitch
Posted 2013-02-03 11:48:03 and read 10592 times.

Quoting packsonflight (Reply 165):
More like PR spin to play down issues with the design and behaviour of the system.

No spin. Boeing admitted the system did not behave as designed.

Topic: RE: FAA Grounds B787 Part 7
Username: 7BOEING7
Posted 2013-02-03 12:01:40 and read 10535 times.

Airplanes grounded not the batteries:

http://www.huffingtonpost.com/2013/0...reamliner-batteries_n_2610986.html

It appears Dreamliner batteries can now be carried as cargo on passenger airplanes.

Topic: RE: FAA Grounds B787 Part 7
Username: sweair
Posted 2013-02-03 12:17:21 and read 10435 times.

Quoting 7BOEING7 (Reply 167):

If it is the batteries and not the plane that is at fault, what an egg on face for some...  

Topic: RE: FAA Grounds B787 Part 7
Username: na
Posted 2013-02-03 12:40:11 and read 10330 times.

Quoting sweair (Reply 168):

Quoting 7BOEING7 (Reply 167):

If it is the batteries and not the plane that is at fault, what an egg on face for some...  

What I dont understand in this affair is why Boeing doesnt or cant offer a quick interim fix with a proven kind of "old style" batteries.

Topic: RE: FAA Grounds B787 Part 7
Username: Stitch
Posted 2013-02-03 12:46:23 and read 10326 times.

Quoting na (Reply 169):
What I dont understand in this affair is why Boeing doesnt or cant offer a quick interim fix with a proven kind of "old style" batteries.

I can think of three reasons off the top of my head:

1) Because "old style" batteries can catch fire and leak, as well, Boeing would have to prove they have properly planned for such events just as they had to do for lithium-ion.

2) To provide the same amp-hours, "old style" batteries would be larger and heavier so Boeing would have to take into account where to place them, possibly needing a redesign of the EE bays. And that would impact meeting #1.

3) Boeing would have to certify that the "old style" batteries can provide the proper level of performance for the systems it needs to power.

Topic: RE: FAA Grounds B787 Part 7
Username: blrsea
Posted 2013-02-03 12:48:00 and read 10307 times.

Quoting na (Reply 169):
What I dont understand in this affair is why Boeing doesnt or cant offer a quick interim fix with a proven kind of "old style" batteries.

Can they use the 777 batteries since it is also proven? I believe the 787 batteries are 2-3 times the capacity of 777 batteries. Would FAA need to certify the bigger capacity "777 style batteries" again? If so, how much time would it add to the certification time?

There were reports on komonews.com earlier that Boeing was contemplating designing a better containment box for the batteries. I have no doubt that they are already testing it out. If that works, we might see the 787s in air in less than month.

Topic: RE: FAA Grounds B787 Part 7
Username: JoeCanuck
Posted 2013-02-03 12:56:19 and read 10277 times.

Quoting 7BOEING7 (Reply 167):

So are the batteries actually currently being flown around in cargo holds? The article doesn't say they are, just that regulations allow the shipping of Li-ion batteries heavier than 11 pounds if they are aircraft certified batteries.

Since the 787's are grounded because of the batteries, and the batteries are no longer certified for use in aircraft, they very likely no longer have the 'heavier than 11 pounds' exemption.

Topic: RE: FAA Grounds B787 Part 7
Username: sonomaflyer
Posted 2013-02-03 13:08:24 and read 10218 times.

Quoting blrsea (Reply 171):
Can they use the 777 batteries since it is also proven? I believe the 787 batteries are 2-3 times the capacity of 777 batteries. Would FAA need to certify the bigger capacity "777 style batteries" again? If so, how much time would it add to the certification time?

There were reports on komonews.com earlier that Boeing was contemplating designing a better containment box for the batteries. I have no doubt that they are already testing it out. If that works, we might see the 787s in air in less than month.

The power needs of the 787 are completely different and much more demanding than a 777. The bays in which the batteries are placed were designed with that battery in mind. To use a 777 battery (or mostly likely a series of 777 batteries will involve redoing battery placement, fit, hook up and re-certifying that part of the system. I don't think this would be a quick fix.

Also, there was also a design review by the FAA just underway on the electrical system in general. If there is data supporting that the issues resulting in the grounding had to do with anything other than the batteries, those parts (say the panels) will need to be checked and replaced (if defective) or something more extensive if its more than faulty parts.

Topic: RE: FAA Grounds B787 Part 7
Username: 7BOEING7
Posted 2013-02-03 13:42:59 and read 9993 times.

Quoting sonomaflyer (Reply 173):
The power needs of the 787 are completely different and much more demanding than a 777

True, but people keep using this statement in relationship to the batteries which I'm not so sure is correct. In case I missed it in the last million posts can somebody definitively say what the rating of the 777 and 787 batteries are for comparison. Both types have to start the APU and I'm guessing there is no big difference there. The only load the 787 battery would have that the 777 doesn't is being backup for the electric brakes and I'm not sure how much of a load that is. Everything else is probably close to the same requirement.

Topic: RE: FAA Grounds B787 Part 7
Username: YVRLTN
Posted 2013-02-03 15:41:50 and read 9644 times.

Quoting cornutt (Reply 137):
The one thing that jumps out at me is that they are going to be examining the battery contactor. I haven't heard anything previously about the contactor possibly having a role. I guess they're looking at the possibility of the contactor creating a short across the battery somehow.

I cant (and dont) believe Boeing are only just looking at this now. I posted back in the original threads the electricians already had a good idea of the issue. A highly volatile battery is the "weakest link" in this particular chain and its destruction is just the effect, not the cause of the issue. Obviously, this has now raised the issue of containment too but the effects are just different depending what system they are part of. Obviously the effect on a lithium battery is going to be a lot more spectacular than a windshield heater or a brake or a galley oven.

Quoting packsonflight (Reply 165):
How can you state it was a FOD. Is that suddenly a fact now? Boeing only said possible FOD if I recall correctly.

Why the extensive rework of the panel if it only was a simple FOD issue? never made any sense to me. More like PR spin to play down issues with the design and behaviour of the system.

What if a busted contactor was the FOD issue and it was never able to be substantiated as it burned up?

Quoting na (Reply 169):
What I dont understand in this affair is why Boeing doesnt or cant offer a quick interim fix with a proven kind of "old style" batteries.

If the issue is not the battery itself, what is to stop any other battery having the same effect? Sure, the current battery is more prone to violent events, but thats not too say a different type of battery could never have any type of event, which I believe is what the NTSB & FAA would like to achieve. So if you connect the same dodgy contactors to a different kind of battery, the risks go down due to the characteristics of the battery, but they do not go away.

Quoting JoeCanuck (Reply 172):
So are the batteries actually currently being flown around in cargo holds?

*Anything* can be flown around as cargo pretty much, as long as you pack it properly and segregate it from other incompatible classes.

Quoting kanban (Reply 144):
nice cherry picking.. and biased extraction. one or two boeing engineers not connected with the program and pissed off about the union negotiations really do not have a lot of creditability

While I agree this source has an ax to grind and I agree with the sentiments in this thread as to outsourcing, there is never smoke without fire (sorry for the horrible analogy...!) and there could well be substance to what he is staying, in principle anyway, if not in detail. I doubt Boeing would ever come out and say yeah this guy is right, even if he was due to the far reaching effect this would have, but I could see quiet changes being implemented in production procedures, or with certain suppliers at least, moving forward. And I am fine with that, Boeing do not need to inform Joe Public of the nitty gritty of their issues, all the public need to know is the FAA have approved their solution.

What doesnt add up though with all the above is how these events just started happening recently, maybe the two ANA & JAL fires were pure coincidence, but I dont believe in coincidences outside of throwing dice generally and the only thing I can really think of to make some sense of it is there has been some software change somewhere which has changed the way certain components function or the thresholds under which they operate.

Topic: RE: FAA Grounds B787 Part 7
Username: trex8
Posted 2013-02-03 16:27:56 and read 9487 times.

Quoting na (Reply 169):
What I dont understand in this affair is why Boeing doesnt or cant offer a quick interim fix with a proven kind of "old style" batteries.

Probably because a Ni-cd battery would take up far more space and weight than a Li-ion and there may be NO space in those bays without significant redesign of the bays. And I would think there would need to be some changes to the charging system/power software etc.

Topic: RE: FAA Grounds B787 Part 7
Username: Aesma
Posted 2013-02-03 16:51:45 and read 9456 times.

Quoting ikramerica (Reply 163):
It's what I've been asserting. The complete grounding is not fact based. It's fear based and CYA related. There is no reason that Boeing shouldn't be allowed to fly test aircraft or pre-delivery aircraft. They would be without passengers other than engineers, constantly near diversion points, would not risk the ETOPS rating of a carrier, etc.
Quoting sweair (Reply 164):
AI flying around must be sort of an show of confidence in the 788 as they have been some of the most vocal against it. The test flight grounding is a step too far imo too, emotional decision making is seldom a good base.

Are you two sure that Boeing really can't fly test flights if they need to ? I doubt it. But there is no point in doing a test flight if you don't have a clue of what to test for. That's what I was alluding earlier, Boeing has known for some time that some things aren't working properly (batteries, electrical system in general) but despite 50 787 in the air every day, they weren't finding the cause.

Topic: RE: FAA Grounds B787 Part 7
Username: rcair1
Posted 2013-02-03 19:26:05 and read 9110 times.

Quoting SonomaFlyer (Reply 155):
Quoting rcair1 (Reply 154):
Outsourcing - and particularly shifting from inhouse to outsource can cause issues - it is a different process and requires different tools and skills. It can delay schedules - and it is not the panacea management may claim or wish. (BTW - I've never been a manager...).A large shift to outsourcing can cause delay and I think it did in the 787 case. But the "everything somebody else builds must be cr*p is just silly." As a design engineer you trust other engineer's work daily - doesn't matter if they are in your building or one down the street or across the world.
Quoting SonomaFlyer (Reply 155):
My point is that Boeing has never outsourced to this degree. The fact someone else designs and builds a part to a spec isn't terrible in itself but does mean Boeing must be vigilant to ensure the quality of the components and competence in assembly.

I would encourage people to read my full post (154). This quoting makes it sound like I agree that outsourcing is the evil and the cause. I do not.

Quoting SonomaFlyer (Reply 155):
I guess the lesson is keep a sharper eye on your subs or design in-house and have someone else build your design?

I disagree. The lesson is you have to assure quality - no matter who builds the part. Remember - my example....

Quoting rcair1 (Reply 154):
The one 'safety' related issue I remember for a product was a fire issue in a stepper motor that did not get de-energized appropriately. The device the motor was in was completely outsourced (built by Canon - that well known low quality OEM that makes crap - yeah right - Canon builds quality products). The f/w that caused the failure was WRITTEN IN HOUSE. When we saw the fires, some initially jumped to a problem in the OEM part. They were wrong. The good ones focused on the issue and determined what was wrong - and fixed it. A line of code commented out during testing and forgot to put back in.

The one issue I dealt with that was safety related (fire - late at night after you left your office - this was office equipment) - was NOT an ODM issue - it was our internal code . The sharp eye was to the inside, not the outside.

Quoting packsonflight (Reply 165):
Why the extensive rework of the panel if it only was a simple FOD issue?

Maybe to make sure that similar FOD could not do the same thing?

Topic: RE: FAA Grounds B787 Part 7
Username: Aesma
Posted 2013-02-03 20:02:53 and read 9026 times.

The FOD caused the fire but the way the system responded is what entailed a redesign, that also included changes to the boxes to minimize the risk of FOD entering them.

Topic: RE: FAA Grounds B787 Part 7
Username: RickNRoll
Posted 2013-02-03 20:03:41 and read 9249 times.

Quoting rcair1 (Reply 178):
I disagree. The lesson is you have to assure quality - no matter who builds the part. Remember - my example....

You can't outsource risk.

Topic: RE: FAA Grounds B787 Part 7
Username: BestWestern
Posted 2013-02-03 20:44:28 and read 9128 times.

Quoting RickNRoll (Reply 180):
You can't outsource risk.

Many companies outsource Risk Management. The importance of risk identification is becoming bigger and bigger in companies.

Topic: RE: FAA Grounds B787 Part 7
Username: kanban
Posted 2013-02-03 22:43:10 and read 8798 times.

Outsourcing came to Boeing via several routes
1) there was heavy section outsourcing for the 757.. didn't work very well. Contracts with several major subs were cancelled and the process brought back in house
2)some Boeing components have always been outsourced (landing gear, a/c pack, api, engines, and up until the 80's engine buildups, struts, nacelles and thrust reversers).
3)Stonecipher believed the economics lay in out sourcing and being an assembly company rather than a manufacturing co.. he may have had the correct thoughts but MD lacked solid implementation and repeatable QA on both the military and commercial programs.
4) 1988 Boeing started delving into World Class Manufacturing and the Toyota manufacturing system.. again the idea was to manufacture as little as possible and become a assembly and integration company. Mulally bought in 100%. The thrust has been toward automotive assembly processes, moving lines, Just in Time parts delivery, Receiving Inspection was a bottle neck all the years I was there, it no longer exists. Parts are delivered directly to the installation points by and from the vendors.

many of the problems experienced in the 787 were a result of the golden handshake Boeing gave to managers. More knowledge left than was anticipated and was backfilled with green MBAs. They read the books, talked the jargon, but had no idea how to implement. There were massive assumptions that all subs were on board. The problem with new managers is they believe the impossible is possible and attempt to outdo each other being proactive. Too often this leads to red faces.

Aside from than that, even when we were a manufacturing company, there were many things that were subbed out.. flight management systems, batteries and electrical systems. Yes we even outsourced wire bundles, hydraulic tubes and insulation blankets.

Where the big change came was outsourcing the installation of these components. In Renton, we had enough problems just trying to move installation back across the tracks. I know lessons were learned by Manufacturing however Materiel or Purchasing or Contracts Management (whatever they call themselves now) was not part of the effort. They were still working out the kinks of suppliers delivering pre inspected quality parts directly to the Puget Sound manufacturing lines.

Watching the 787 unfold, it was obvious that the supply lines into the suppliers were fragile and not robust enough for the task at hand. What worked in Puget Sound because of a 15 year process development, didn't work where the culture was not up to speed. Example Boeing mechanics self inspect most of their work, yet the new subs while understanding the concept still 'believed' someone else would catch the errors.

However saying that, the current problems although not with old integrated suppliers, are probably wholly owed by one. The systems involved are not Boeing designed but procured as SCD's (specification control drawings). In them Boeing says "I want this procures to happen in a hardware system that has this inputs and these outputs, and fits an space envelope of x by y by z" . The result is vendor proprietary.

Normally Boeing would set up a integration lab and all the pieces would be hooked up and tested. I have no way of knowing if they did. However, looking at the pieces gleaned from the press, I suspect the situation we're facing would not have been identified because the lab sits in a building, where as I feel actual aircraft usage and abuse by rampers/cleaners not familiar with the limitations may be part of the mix. Note to rammers.. I'm not implying sloppiness or intentional mistreatment, but with the mix of systems/aircraft differences you face and the variability of crew members, perhaps the constraints were not adequately communicated. Right now there is a lot of pointing at the numbers of batteries removed and most of that is from over use... that issue clouds the main issue to some degree although there maybe some correlation.

There is installation question in this.. are the batteries and electrical components installed in FAL or in subassembly or a combination?

Topic: RE: FAA Grounds B787 Part 7
Username: WingedMigrator
Posted 2013-02-03 22:52:14 and read 8748 times.

Quoting BestWestern (Reply 178):
Many companies outsource Risk Management

Sure, but that should never be confused with outsourcing the risk itself. If it's your product, you own the risk, whether or not you like it or even know it.

Topic: RE: FAA Grounds B787 Part 7
Username: BestWestern
Posted 2013-02-03 22:59:17 and read 8732 times.

Quoting WingedMigrator (Reply 180):
Sure, but that should never be confused with outsourcing the risk itself. If it's your product, you own the risk, whether or not you like it or even know it.

The risk remains, but can be kind of out-sourced by insuring yourself against it, but to do that, you have to identify the risk, its gravity, likelihood of occurrence, frequency of occurrence and impact (financial and reputation) if it does happen.

I wonder what the damage to reputation the whole 787 saga has had on Boeing?

Topic: RE: FAA Grounds B787 Part 7
Username: rwessel
Posted 2013-02-04 00:04:53 and read 8569 times.

Quoting 7BOEING7 (Reply 171):
True, but people keep using this statement in relationship to the batteries which I'm not so sure is correct. In case I missed it in the last million posts can somebody definitively say what the rating of the 777 and 787 batteries are for comparison. Both types have to start the APU and I'm guessing there is no big difference there. The only load the 787 battery would have that the 777 doesn't is being backup for the electric brakes and I'm not sure how much of a load that is. Everything else is probably close to the same requirement.

One of the big differences is that to do almost anything on the 787, you have to fire up one of the main computer racks to manage the process. Open the refueling panel, and one of the racks fires up to manage the fuel loading, etc. That results in a substantially higher base load.

Topic: RE: FAA Grounds B787 Part 7
Username: BoeingVista
Posted 2013-02-04 01:39:55 and read 8284 times.

Quoting 7BOEING7 (Reply 174):
Both types have to start the APU and I'm guessing there is no big difference there.

The 777 APU is rated to produce 120 KVA whereas the 787 APU produces 450 KVA from 2 generators so we have to assume that the batteries used to start the 787 APU draw considerably more power than the 777's, the 787 batteries certainly have more power that 777 batteries

777 batteries: 47 Ah 48 kg ( x 2 = 96 kg) [As I understand it only one battery is involved in the start with the other as backup, could be wrong]
787 batteries: 65 Ah 29 kg

777 APU starter draw is described as 500 amps, 1000 peak down to 200 at starter cut off over 90 seconds = 12.5 Ah approximately 25% of total potential battery power.

If somebody who has read the 787 manual provide details of the current drain from starting the APU we could maybe work out now much 'work' the APU battery is required to do and its recharge cycle time.

Also we can see that the 787 batteries pack a punch.

777 batteries produce 1 amp hour per Kg,
787 batteries produce 2.25 amp hour per Kg and save 140 Kg in total weight.

Quoting Aesma (Reply 179):
The FOD caused the fire but the way the system responded is what entailed a redesign, that also included changes to the boxes to minimize the risk of FOD entering them.

Technically FOD was presumed to be the source of the fire, no FOD was ever found. The only way that Boeing could replecate the fault was to introduce FOD so they presumed this to be the source of the fault. The problem then as now is that the 787 leaves no evidence of what caused the electrical fault (discovered so far anyway).

[Edited 2013-02-04 01:41:47]

[Edited 2013-02-04 01:42:43]

Topic: RE: FAA Grounds B787 Part 7
Username: sphealey
Posted 2013-02-04 03:08:48 and read 7975 times.

Quoting BestWestern (Reply 178):
Quoting RickNRoll (Reply 180):
You can't outsource risk.

Many companies outsource Risk Management. The importance of risk identification is becoming bigger and bigger in companies.

The word "risk" should be removed from the vocabulary of US business. It has been stretched to the point of meaninglessness, and managers (particularly in financial institutions, but in manufacturing entities as well) now spend much of their time putting in 'processes' to 'manage' some hyper-technical concept whist completely ignoring the plain old-fashioned meaning of the word. Then are utterly surprised when the risk (the real risk, not the "risk") materializes.

sPh

Topic: RE: FAA Grounds B787 Part 7
Username: Aesma
Posted 2013-02-04 06:56:09 and read 7391 times.

Quoting BoeingVista (Reply 183):
The 777 APU is rated to produce 120 KVA whereas the 787 APU produces 450 KVA from 2 generators so we have to assume that the batteries used to start the 787 APU draw considerably more power than the 777

But the 777 APU makes compressed air. What would be interesting to know is its shp or simply the model used in both planes.

Topic: RE: FAA Grounds B787 Part 7
Username: planewasted
Posted 2013-02-04 07:22:54 and read 7278 times.

Quoting BoeingVista (Reply 183):
777 batteries produce 1 amp hour per Kg,
787 batteries produce 2.25 amp hour per Kg and save 140 Kg in total weight.

But are the voltages the same? Total stored energy is amp hours times voltage.

Topic: RE: FAA Grounds B787 Part 7
Username: 7BOEING7
Posted 2013-02-04 08:38:21 and read 7077 times.

Quoting aloges (Reply 132):
Is that not a bug in flightradar showing the wrong model?Probably not, there was also VT-ANK operating AIC551 today. FR24.com says it went to VTZ (Visakhapatnam), airindia.com says it went to BOM just like 553 and 555. However, none of the flights can be found in Air India's downloadable pdf timetable or on the airport websites of DEL and BOM. The flight number also don't bear a resemblance to Air India's regular numbers for flights between those cities.Test flights? Leprechauns in the database?

They got permission to return to base.

http://www.huffingtonpost.com/2013/0...eing-787-dreamliner_n_2613649.html

[Edited 2013-02-04 08:39:51]

Topic: RE: FAA Grounds B787 Part 7
Username: par13del
Posted 2013-02-04 09:34:25 and read 6738 times.

Quoting Aesma (Reply 174):
Are you two sure that Boeing really can't fly test flights if they need to ? I doubt it. But there is no point in doing a test flight if you don't have a clue of what to test for.

Boeing is continuing to build 787's, those a/c require test flights which have nothing to do with the battery issue, I took their comments to be test flying in relation to production.

Topic: RE: FAA Grounds B787 Part 7
Username: sonomaflyer
Posted 2013-02-04 10:24:04 and read 6524 times.

Quoting 7BOEING7 (Reply 187):
They got permission to return to base.

http://www.huffingtonpost.com/2013/0....html

Yet again, the media got it wrong. The FAA grounding order has no legal effect on foreign carriers flying to/from foreign destinations. India's own regulators mirrored the FAA a short time later but have also allowed re-positioning flights.

I would expect the FAA to allow flight testing once Boeing is in a position to demonstrate (with NTSB input) what happened in the two events and have a fix in place. It's pinning down what happened that is the challenge in these cases.

Topic: RE: FAA Grounds B787 Part 7
Username: Wisdom
Posted 2013-02-04 10:53:01 and read 6374 times.

The FAA is right to ground everything.
Fire and smoke are very dangerous events. They can incapacitate both the aircraft and the crews flying them.

A fire on a test flight would be as dangerous as a fire on a commercial flight.
Fires can doom an aircraft in less time than you can ever imagine.

In well-known high profile crashes, it only took less than 5 minutes from detection to loss of control.

Air Canada 797 would be the best if you want to have an idea of what it looks like.
AC797 was lucky in that the source of the fire was far from the cockpit.

http://www.youtube.com/watch?v=8dOkBP-K0o0

Topic: RE: FAA Grounds B787 Part 7
Username: DTW2HYD
Posted 2013-02-04 11:15:11 and read 6214 times.

Quoting sweair (Reply 161):
AI flying around must be sort of an show of confidence in the 788

Probably they rigged a webcam in the electronics bay. Would be even easier if 787 has WiFi(Not sure if AI has it) and a iPad with flight crew.

Topic: RE: FAA Grounds B787 Part 7
Username: Navigator
Posted 2013-02-04 11:32:46 and read 6122 times.

Quoting rwessel (Reply 182):
One of the big differences is that to do almost anything on the 787, you have to fire up one of the main computer racks to manage the process. Open the refueling panel, and one of the racks fires up to manage the fuel loading, etc. That results in a substantially higher base load.

I agree. The 787 Dreamliner is more dependent on electrical power than other planes. The Airbus A350 will have about a third of 550kVA power requirement compared to the Dreamliner. The electrical architecture of the 787 requires a lot of power compared to any other airliner.

Topic: RE: FAA Grounds B787 Part 7
Username: PITingres
Posted 2013-02-04 12:59:20 and read 5695 times.

Quoting DTW2HYD (Reply 191):
Probably they rigged a webcam in the electronics bay.

I'll bet that they did no such thing. Why on earth would they bother? There's nothing they could do about a battery poof in flight anyway, and they would get all the feedback they need via ordinary cockpit messages if something does go wrong with it.

Topic: RE: FAA Grounds B787 Part 7
Username: kanban
Posted 2013-02-04 13:10:18 and read 5624 times.

Quoting PITingres (Reply 195):
There's nothing they could do about a battery poof in flight anyway,

They may have put two guys down there with several sacks of sand to pour on the batteries if needed.      

Topic: RE: FAA Grounds B787 Part 7
Username: TheSultanOfWing
Posted 2013-02-04 13:11:01 and read 5637 times.

What I wonder about is whether new B787 customers that were supposed to get their planes in January this year are suffering even further delays? Or will new customers likely see delivery delays in February or March?


Cheers,


FH

Topic: RE: FAA Grounds B787 Part 7
Username: prebennorholm
Posted 2013-02-04 15:18:47 and read 5167 times.

Quoting BoeingVista (Reply 183):
777 batteries: 47 Ah 48 kg ( x 2 = 96 kg) [As I understand it only one battery is involved in the start with the other as backup, could be wrong]
787 batteries: 65 Ah 29 kg

Two 777 batteries = 96 kg
Two 787 batteries = 58 kg

If we scale the 777 batteries to 787 capacity, then 96 x 65 / 47 = 133 kg

Quoting BoeingVista (Reply 183):
787 batteries produce 2.25 amp hour per Kg and save 140 Kg in total weight.

Something is wrong here. You cannot save 140 kg on something which is only 133 kg.

So saving on two 65 Ah 28VDC batteries is 133 minus 58 = 75 kg.

That saving - 75kg - could easily be reduced considerably, or evaporate away, if the fix ends up with improved containment systems.

Quoting BoeingVista (Reply 183):
777 batteries produce 1 amp hour per Kg,
787 batteries produce 2.25 amp hour per Kg

  

Topic: RE: FAA Grounds B787 Part 7
Username: DTW2HYD
Posted 2013-02-04 15:50:57 and read 5009 times.

Quoting kanban (Reply 194):
They may have put two guys down there with several sacks of sand to pour on the batteries if needed.

Or, Boeing can design drop-off external battery pods. In case of battery fire, switch to alternate battery power source, release bad battery and land at closest airport.

Topic: RE: FAA Grounds B787 Part 7
Username: 14ccKemiskt
Posted 2013-02-04 16:29:10 and read 4949 times.

Seems like the Dreamliner might be back in the air soon

http://seattletimes.com/html/busines...8074_dreamlinertestflightsxml.html

[Edited 2013-02-04 16:30:41]

Topic: RE: FAA Grounds B787 Part 7
Username: RickNRoll
Posted 2013-02-04 16:32:29 and read 4903 times.

Possibly not according to the article. The flights are for testing and investigation purposes only.

However, 787 passenger flights won’t resume soon. In airline service, the Dreamliner is still likely to stay grounded for weeks, if not months, two sources said.

Even when Boeing arrives at a workable fix, its engineers will have to design, build and thoroughly test the solution.


Boeing is making progress, which is good, but this is still in the investigation and exploring of fixes stage.

Topic: RE: FAA Grounds B787 Part 7
Username: 14ccKemiskt
Posted 2013-02-04 16:42:27 and read 4838 times.

Quoting RickNRoll (Reply 199):
Possibly not according to the article. The flights are for testing and investigation purposes only.

Well, a test flight is better than no flight.

But seriously, I'm not sure if even Boeing's top priority is to get the planes back in service asap. Even if the battery problems are fixed, the list of other flaws might be too long for them not to also address during this down-period. The battery failures has been spelled out as the main reason for the grounding but the other faults might have added to it.

Another grounding would be right out disastrous for the program.

Topic: RE: FAA Grounds B787 Part 7
Username: RickNRoll
Posted 2013-02-04 16:47:26 and read 4836 times.

Quoting 14ccKemiskt (Reply 200):
Well, a test flight is better than no flight.

Like I said, it looks like Boeing is making progress, which is good.

Topic: RE: FAA Grounds B787 Part 7
Username: prebennorholm
Posted 2013-02-04 16:55:22 and read 4913 times.

Quoting BoeingVista (Reply 183):
777 APU starter draw is described as 500 amps, 1000 peak down to 200 at starter cut off over 90 seconds = 12.5 Ah approximately 25% of total potential battery power.

If somebody who has read the 787 manual provide details of the current drain from starting the APU we could maybe work out now much 'work' the APU battery is required to do and its recharge cycle time.

Thanks a lot, BoeingVista, for those 777 figures. Yes, it would be interesting to have the same Numbers for the 787.

rcair1 provided this link to the 787 battery cell data sheet: http://www.s399157097.onlinehome.us/SpecSheets/LVP10-65.pdf

It says that maximum discharge rate is 5.0 CA. That means that maximum allowed discharge rate in amps is 5 times the capacity in amp hours - that's 5 x 65 = 325 amps. Compared to 777 data it seems to be a rather low figure. Which makes one wonder whether the 787 battery is operated too close to, or maybe beyond, its limits.

Discharge very much beyond limit is first of all very damaging to capacity. Degraded capacity might be one reason why so many batteries are reported to have drained prematurely?

Extremely severe violation of discharge limits can also produce internal shorts, which can trigger a thermal runaway.

On the other hand, a Li-Ion discharge limit of 5.0 seems a rather conservative figure by modern standards. Li-Ion batteries, which are designed for high power use, are today more like limited to 20 CA, not 5 CA.

Discharge rate has always been the weak point of Li-Ion batteries compared to NiCad and lead-acid. But in this respect they have improved impressively during the past. 5.0 CA was considered good ten years ago, but not in year 2013.

Any thoughts?

Topic: RE: FAA Grounds B787 Part 7
Username: KELPkid
Posted 2013-02-04 17:52:20 and read 4694 times.

Quoting DTW2HYD (Reply 197):
Or, Boeing can design drop-off external battery pods. In case of battery fire, switch to alternate battery power source, release bad battery and land at closest airport.

§ 91.15 Dropping objects.
No pilot in command of a civil aircraft may allow any object to be dropped from that aircraft in flight that creates a hazard to persons or property. However, this section does not prohibit the dropping of any object if reasonable precautions are taken to avoid injury or damage to persons or property.

 

Topic: RE: FAA Grounds B787 Part 7
Username: Shenzhen
Posted 2013-02-04 17:54:40 and read 4662 times.

Quoting RickNRoll (Reply 177):
You can't outsource risk.

It's called insurance.

Topic: RE: FAA Grounds B787 Part 7
Username: NAV20
Posted 2013-02-04 18:47:04 and read 4491 times.

Just to keep the 'factfile' up to date:-

1. This story explains why two Indian 787s were permitted to fly (without passengers) last week - high parking charges  :-

http://www.brisbanetimes.com.au/trav...rounding-order-20130205-2dvks.html

2. Boeing appear at least to be making progress on 'containment.'

"One fix Boeing is looking at closely is a way to strengthen the lithium ion battery%u2019s ability to contain any internal overheating and to improve the venting system whereby hot liquid or gaseous products exit the battery box and are directed outside the airplane, two sources said."

And, later in the same story, there is mention of the question of possible moisture being involved in the incidents:-

"According to an industry source, one theory Boeing is investigating is that moisture getting inside the battery may have contributed to the recent incidents."

http://seattletimes.com/html/busines...8074_dreamlinertestflightsxml.html

Just a hunch at this stage - but I have the feeling that moisture (affecting either the batteries themselves, or the associated wiring) may well turn out to be a contributing factor in the now-evident short-circuiting.

[Edited 2013-02-04 18:48:49]

Topic: RE: FAA Grounds B787 Part 7
Username: sonomaflyer
Posted 2013-02-04 18:49:06 and read 4452 times.

Quoting 14ccKemiskt (Reply 200):
But seriously, I'm not sure if even Boeing's top priority is to get the planes back in service asap. Even if the battery problems are fixed, the list of other flaws might be too long for them not to also address during this down-period. The battery failures has been spelled out as the main reason for the grounding but the other faults might have added to it.

Another grounding would be right out disastrous for the program.

Its safe to assume that Boeing has multiple teams working on multiple issues at the same time. They should have teams on:

1. Battery;
2. Panels/components of panels;
3. Software controlling the electrical system;
4. Charging/discharging system.

There may be some overlap and perhaps there are more or less categories but suffice to say, Boeing has to be working on examining the entire electrical system since that is where a vast majority of the issues for this plane reside.

[Edited 2013-02-04 18:51:27]

Topic: RE: FAA Grounds B787 Part 7
Username: prebennorholm
Posted 2013-02-04 18:54:40 and read 4432 times.

Quoting Shenzhen (Reply 204):
Quoting RickNRoll (Reply 177):
You can't outsource risk.

It's called insurance.

Oh, I didn't know that. A contractor fails to deliver to specs, and your lost billions just magically drop like autumn leaves on your bank account. I must tell that to my CEO tomorrow.

Or maybe better yet: I should quit my job tomorrow and start a new insurance company?

Maybe I am old-fashioned, but in my world there is no substitute to producing products and services which the customers want to pay for because they need them and can use them.

In other words, like RickNRoll said: You can't outsource risk.

Topic: RE: FAA Grounds B787 Part 7
Username: BoeingVista
Posted 2013-02-04 19:09:42 and read 4426 times.

Quoting prebennorholm (Reply 196):

Quoting BoeingVista (Reply 183):
777 batteries: 47 Ah 48 kg ( x 2 = 96 kg) [As I understand it only one battery is involved in the start with the other as backup, could be wrong]
787 batteries: 65 Ah 29 kg

Two 777 batteries = 96 kg
Two 787 batteries = 58 kg

I may have been a bit unclear here, the 777 has 2 sets of 2 batteries, 4 batteries total whereas the 787 has 2 sets of 1 battery 2 batteries total. I was doing the calculations for APU batteries so 1 set of batteries.

For weight we have 4 x 48 = 192 kg for 777 and 2 x 29 = 58 for 787 so 134 Kg difference per shipset so I had an adding error in there somewhere.

Quoting Aesma (Reply 185):
But the 777 APU makes compressed air. What would be interesting to know is its shp or simply the model used in both planes.

The 777 APU also makes electricity

777 APU is Honeywell 331-500
787 APU is Hamilton Sundstrand APS5000

Topic: RE: FAA Grounds B787 Part 7
Username: Unflug
Posted 2013-02-04 19:34:58 and read 4354 times.

Quoting kanban (Reply 194):
They may have put two guys down there with several sacks of sand to pour on the batteries if needed.

That's the way to go - creates new jobs, too!

 

Topic: RE: FAA Grounds B787 Part 7
Username: Shenzhen
Posted 2013-02-04 19:57:19 and read 4288 times.

Quoting prebennorholm (Reply 207):
Quoting Shenzhen (Reply 204):
Quoting RickNRoll (Reply 177):
You can't outsource risk.

It's called insurance.

Oh, I didn't know that. A contractor fails to deliver to specs, and your lost billions just magically drop like autumn leaves on your bank account. I must tell that to my CEO tomorrow.

Or maybe better yet: I should quit my job tomorrow and start a new insurance company?

Maybe I am old-fashioned, but in my world there is no substitute to producing products and services which the customers want to pay for because they need them and can use them.

In other words, like RickNRoll said: You can't outsource risk.

Insurance is the transfer of risk, there is no other purpose.

cheers

[Edited 2013-02-04 20:19:37]

Topic: RE: FAA Grounds B787 Part 7
Username: B777fan
Posted 2013-02-04 22:14:03 and read 3945 times.

Quoting NAV20 (Reply 122):
Perhaps the more knowledgeable posters on here can shed light on the part 'battery contactors' play in electrical circuits, and in what sort of circumstances they could contribute to battery trouble?

With these long threads it's hard to tell whether you got an answer to this or not.

A battery contactor is just a relay. They can be fancy or dead simple. The most simple is...

The big fat positive wire from the battery goes to one post on the contactor. The other post on the contactor is connected to what you want to power. Then a switch is thrown that opens or closes the contactor. It is a simple way to disconnect the battery immediately from both the load and/or charging circuit.

In the past they were all mechanical but that's not true anymore. They also are usually co-located with the battery so that the big fat wire from the postive post of the battery is as short as possible.

I would be surprised if the contactor wasn't located inside the battery box or immediately outside of it. I would also not be surprised if it was a solid state device talking with the battery control circuitry.

In a little Cessna, when you hit the Master switch you are closing a contactor that connects the battery to the main bus.

Topic: RE: FAA Grounds B787 Part 7
Username: RickNRoll
Posted 2013-02-04 22:32:02 and read 3891 times.

Quoting Shenzhen (Reply 204):
It's called insurance.
Quoting Shenzhen (Reply 210):
Insurance is the transfer of risk, there is no other purpose.

cheers

In a simple way, it is, but what we are talking about here is something more complex than risk we often can't control, such as flooding or earthquakes.

Say this incident could be and was insured for. Would the Boeing board be sitting back, relaxed saying "No matter, we have insurance".

Topic: RE: FAA Grounds B787 Part 7
Username: 777ER
Posted 2013-02-05 04:28:15 and read 3243 times.

FAA Grounds 787, Part 8 (by 777ER Feb 5 2013 in Civil Aviation)


The messages in this discussion express the views of the author of the message, not necessarily the views of Airliners.net or any entity associated with Airliners.net.

Copyright © Lundgren Aerospace. All rights reserved.
http://www.airliners.net/