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mattya9
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NTSB Unhappy With Steps Taken So Far By FAA On 787

Thu May 29, 2014 6:50 pm

It says in the article, "The NTSB is plainly unhappy with the steps taken so far by the FAA to understand the specific risks posed by lithium-ion batteries". I thought the battery problem was fixed?

http://news.yahoo.com/787-safe-fly-n...n-t-think-094500241--politics.html

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nomadd22
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NTSB Unhappy With Steps Taken So Far By FAA On 787

Thu May 29, 2014 6:54 pm

That's a long way from saying the plane isn't safe to fly. We can go to Yahoo news for garbage headlines like that without having to see them here.
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Stitch
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NTSB Unhappy With Steps Taken So Far By FAA On 787

Thu May 29, 2014 6:58 pm

I assume this article is in regards to the NTSB's suggestions in regards to testing new systems technologies in commercial aircraft, which we were recently discussing here:
Ntsb Safety Recommendation: 787 Battery Issue (by hivue May 22 2014 in Civil Aviation)
 
a318
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NTSB Unhappy With Steps Taken So Far By FAA On 787

Thu May 29, 2014 6:59 pm

Seeing as the FAA announced the 5.5 hour ETOPS rating; I'd say the 787 is just as safe, if not safer then any other commercial aircraft in the air!
 
art
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NTSB Unhappy With Steps Taken So Far By FAA On 787

Thu May 29, 2014 7:00 pm

Err... no. Perhaps the NTSB is saying that here is a question mark. May be small, tiny, miniscule.

To quote -

The NTSB is plainly unhappy with the steps taken so far by the FAA to understand the specific risks posed by lithium-ion batteries: “Aircraft manufacturers,” says the Board, “need to evaluate whether additional requirements and testing are necessary to ensure aircraft-level safety.”
 
KELPkid
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NTSB Unhappy With Steps Taken So Far By FAA On 787

Thu May 29, 2014 7:01 pm

Well, considering that the 787 has now racked up hundreds of thousands of flight hours without a serious incident...and there are ~140-150 of trhem in service now    The only serious problem was that Boeing underestimated the occurence of LiIon thermal runaway scenarios. And now steps have been taken to assume that 1) it has a realistic chance of happening in service and 2) to prevent it from doing any damage when it happens. IIRC, NH or JA has had one battery incident since the fixes were implemented, and this one did far less damage with the new battery containment system...
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mattya9
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NTSB Unhappy With Steps Taken So Far By FAA On 787

Thu May 29, 2014 7:08 pm

Quoting KELPkid (Reply 5):

My thoughts exactly; hence why I put a "?" in my title. I hadn't heard of any major issues since the ANA incident a little while back. Wanted to post the article just in case anyone had heard something similar from any other news sources.

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Ruscoe
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NTSB Unhappy With Steps Taken So Far By FAA On 787

Thu May 29, 2014 11:42 pm

My overall impression is that the problem of why the batteries failed is not fully understood, but Boeing has put in place design changes to the battery itself, to make a thermal run away very low probability.
Then on top of that they have added their titanium containment box, which has been shown to work in testing, to protect the aircraft should a catastrophic battery event occur.

I have read of one event since the battery fix where a few cells failed in the battery, but there was no thermal event, and the box encasement works as planned. (Sorry can't remember where or when)

I think it is likely that the NTSB wants to know the root cause of the problem, not only for the 787, or the future 350, but because there have been several aircraft brought down carrying Li-ion batteries carried as freight, where the batteries were thought to be the culprit that started the fire.

So I hope someone keeps looking, bit imo it should not make the 787 unsafe, or stop Airbus introducing the batteries on the 350 in the future,

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Stitch
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NTSB Unhappy With Steps Taken So Far By FAA On 787

Fri May 30, 2014 12:00 am

Quoting Ruscoe (Reply 7):
I have read of one event since the battery fix where a few cells failed in the battery, but there was no thermal event, and the box encasement works as planned.

It was a single cell failure in a JL 787 parked at NRT on 14 January 2014. There was some electrolyte leakage, but it was by design as the safety valve had opened in response to the pressure increase and the new containment system worked as designed.
 
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777Jet
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NTSB Unhappy With Steps Taken So Far By FAA On 787

Fri May 30, 2014 6:49 am

Quoting a318 (Reply 3):
Seeing as the FAA announced the 5.5 hour ETOPS rating; I'd say the 787 is just as safe, if not safer then any other commercial aircraft in the air!

Likewise. In fact, if the NTSB came out tomorrow and actually said it was not safe I would ignore them as long as the 787 still had its current ETOPS rating  

[Edited 2014-05-29 23:50:29]
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wjcandee
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NTSB Unhappy With Steps Taken So Far By FAA On 787

Fri May 30, 2014 8:13 am

Quoting art (Reply 4):
To quote -

The NTSB is plainly unhappy

It's an artcle from The Daily Beast. It's not journalism. Journalists don't uses phrases like "The NTSB is plainly unhappy." That's a judgment. That makes this an opinion piece fronting as journalism.

The fact is that the NTSB is talking about what it views as the need for changes in how certification of future aircraft is accomplished when they are going to fly with Li-on batteries. It also recognizes that there are lots of lithium batteries flying around out there without anything like the containment structure that exists on the 787.

With regard to that structure, there is no indication -- none -- that the current setup isn't sufficient to contain and vent the gasses from a full-fledged thermal runaway of an entire 787 battery. In fact, the original setup would likely have been adequate with any kind of in-flight conflagration involving the battery. The revised setup is intentionally overdesigned.

It's not a bad thing that the NTSB thinks that the use of lithium batteries should generally be reviewed. However, that hardly makes the 787 unsafe, particularly after the alterations that have been made.
 
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PITingres
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NTSB Unhappy With Steps Taken So Far By FAA On 787

Fri May 30, 2014 1:11 pm

Quoting mattya9 (Thread starter):
"The NTSB is plainly unhappy with the steps taken so far by the FAA to understand the specific risks posed by lithium-ion batteries". I thought the battery problem was fixed?

You're mixing up two different things. It helps if you read or at least skim the NTSB letter that the article is about.

The NTSB is worried that a) we don't know enough about why these batteries fail catastrophically; b) the tests that were used to qualify Li batteries are plainly insufficient and we don't know enough to come up with a sufficient set of qualifying tests; b) the process by which certification guidelines for lithium batteries were drawn up might be flawed; and c) in general, the process by which we arrive at certification guidelines for new and possibly incompletely-understood technologies might be flawed.

This is very different from a safety of flight problem, and nowhere in the letter (that I can see) does the NTSB express a concern that there is still a safety of flight issue. The original design assumed that we knew enough about that batteries to prevent a fire. That turned out to be wrong, so the current design allows a fire and prevents it from being a problem. (Of course, it also takes additional steps to discourage a battery failure, but since we don't understand the failure mode completely, we don't know if those steps would suffice by themselves.)

So no, the NTSB is not saying that the 787 isn't safe to fly.
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DTWPurserBoy
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NTSB Unhappy With Steps Taken So Far By FAA On 787

Fri May 30, 2014 1:12 pm

Fires with lithium ion batteries on aircraft is not a new one. There have been instances of cargo fires that were believed started by shipments of these and there have been instances of passenger laptops catching fire inflight. Every year we have to go through a special fire extinguishing scenario in recurrent training on how to put a fire out on them. You can't just dump a fire extinguisher on them--they reignite very quickly, even when covered with ice.
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PanAm1971
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NTSB Unhappy With Steps Taken So Far By FAA On 787

Fri May 30, 2014 2:08 pm

This also smacks of a careful CYA maneuver by the NTSB. If something happens... they can say they warned the FAA. This is a common Washington activity among many agencies covering all sorts of safety issues and should not be interpreted as anything else beyond bureaucratic maneuvering.
 
rfields5421
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NTSB Unhappy With Steps Taken So Far By FAA On 787

Fri May 30, 2014 4:49 pm

Quoting PanAm1971 (Reply 13):
This also smacks of a careful CYA maneuver by the NTSB. If something happens... they can say they warned the FAA.

Not really.

The NTSB is often in disagreement with the FAA, ICAO and other national aviation authorities over 'safety' issues. They have the same type disagreements with the Department of Transportation over automobile, bus and truck safety, the Coast Guard and DOT over marine safety and over pipeline safety.

The job of the NTSB in addition to accident investigation is to identify issues and make recommendations to improve the safety process of transportation channels.

The NTSB is not limited to practical technical or financial considerations. The NTSB is not in the business of writing implementation regulations or defining inspection standards.

It is the job of the FAA (and other DOT agencies) to evaluate NTSB recommendations, determine if they are things which need to be implemented, and determine how to implement those items. To write the regulations, the compliance standards and the inspection standards.


Yes, the NTSB is concerned about the entire process of certification of Lithium batteries for use in aircraft, and automobiles, and eventually boats, maybe even trains some day.

That's all this statement/ release says.
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strfyr51
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NTSB Unhappy With Steps Taken So Far By FAA On 787

Fri May 30, 2014 6:20 pm

Since the NTSB is not Now nor were they in on the design and testing OF the batteries And?
Since the Boeing Fix is over a year OLD?? I'm not sure Why the NTSB needs to KNOW why the batteries failed.
What the crux of the matter is, is to monitor whether the batteries fial AGAIN.. Things fail on airplanes all the time.
Nobody can ever know what or why anything failed until the repair is accomplished and the part is torn down for Evaluation and repair.
Boeing tore down the suspect batteries and redesigned the battery and the cases.
On top of that they installed them in a vault like apparatus to isolate them. Overkill?? maybe..
But who better to cause the overkill Before the problem got too big and caused a loss of public confidence?
 
KELPkid
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NTSB Unhappy With Steps Taken So Far By FAA On 787

Fri May 30, 2014 10:07 pm

Quoting strfyr51 (Reply 15):
Since the NTSB is not Now nor were they in on the design and testing OF the batteries And?
Since the Boeing Fix is over a year OLD?? I'm not sure Why the NTSB needs to KNOW why the batteries failed.
What the crux of the matter is, is to monitor whether the batteries fial AGAIN.. Things fail on airplanes all the time.
Nobody can ever know what or why anything failed until the repair is accomplished and the part is torn down for Evaluation and repair.
Boeing tore down the suspect batteries and redesigned the battery and the cases.
On top of that they installed them in a vault like apparatus to isolate them. Overkill?? maybe..
But who better to cause the overkill Before the problem got too big and caused a loss of public confidence?

IMHO, the only way they are ever going to find out what is going on is to put a datalogger on the battery cells that show intake current, and a datalogger on the charging bus that shows current being fed to the battery, and do this for every plane in operation until another one pops a battery cell, and then corollate the data with the FDR and/or maintenance loggers to figure out what was going on on board the plane at the time   
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PITingres
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NTSB Unhappy With Steps Taken So Far By FAA On 787

Fri May 30, 2014 11:11 pm

Quoting strfyr51 (Reply 15):
I'm not sure Why the NTSB needs to KNOW why the batteries failed.

Because it's an unknown. The batteries weren't supposed to be able to fail like that. It's not so much the failure per se, it's the gap between the original engineering model / analysis and the actual result that is troubling. If I were a battery engineer, I'd want to know myself.

If the battery guys had said "yeah, these things just pop off every now and then", I think it would be different. And of course the containment would have been designed in from the start if that were the case.

From a practical standpoint, the new containment box is eating up the weight savings of Li battery (leaving only the energy density / size benefit). If we knew exactly what conditions lead to battery failure, maybe the box could be lightened up a bit.
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SANFan
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NTSB Unhappy With Steps Taken So Far By FAA On 787

Fri May 30, 2014 11:36 pm

Quoting mattya9 (Thread starter):
It says in the article, "The NTSB is plainly unhappy with the steps taken so far by the FAA to understand the specific risks posed by lithium-ion batteries".

I strongly suggest the title of this thread be changed! Even on a top aviation forum like this, the current thread title is VERY misleading -- question mark or not.

bb
 
rg787
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NTSB Unhappy With Steps Taken So Far By FAA On 787

Sat May 31, 2014 3:52 am

If I got this thing correctly, we don't know how or why these batteries fail, we only know they start a hell of a fire and if not well contained it could bring an airplane down. Well, if I am right, thats a big issue. Yes, things fail and yes, things happen every now and then, the problem with not knowing why and how they happen is that you don't know the limit of it.

Lets say until now, we had fires and other consequences caused by the failing of the batteries that gone until a certain point and that Boeing or whoever uses Li-ion batteries over designed protection measures to prevent this from causing a big catastrophe. Ok, now imagine if beyond the failure of these batteries, something else happens and, combined, these two things can't be controlled or can cause the protection measure not to be sufficient. Well, you have a plane going down.

As people always say, a catastrophe is a combination of failures. To this point we are letting those batteries fail and to this point they haven't caused much of a problem beyond repair, but this could change.

Just my two cents, I am not an engineer nor a mech, so I don't know what else could be caused by those batteries or failures inside the cells, but it could be a problem.
 
mptpa
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NTSB Unhappy With Steps Taken So Far By FAA On 787

Sat May 31, 2014 5:27 am

That heading for this thread is an utter exaggeration and should be changed. NTSB never said B787s are unsafe. They only said that FAA should 're-evaluate' the way they test the Li-Ion to address the risks that were not part of the original certification tests (to put through real life scenario instead of lab conditions).
 
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Stitch
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NTSB Unhappy With Steps Taken So Far By FAA On 787

Sat May 31, 2014 2:55 pm

Quoting nomadd22 (Reply 1):
That's a long way from saying the plane isn't safe to fly. We can go to Yahoo news for garbage headlines like that without having to see them here.
Quoting mptpa (Reply 20):
That heading for this thread is an utter exaggeration and should be changed.
Quoting SANFan (Reply 18):
I strongly suggest the title of this thread be changed! Even on a top aviation forum like this, the current thread title is VERY misleading -- question mark or not.

It's all about the page hits - this one is closing on 14,000 views, whereas the "Ntsb Safety Recommendation: 787 Battery Issue" thread only has 5000.  
Quoting rg787 (Reply 19):
If I got this thing correctly, we don't know how or why these batteries fail, we only know they start a hell of a fire and if not well contained it could bring an airplane down.

We don't know why they fail, but in both cases where they did, there was not a "hell of a fire" and neither frame was anywhere near being in danger of suffering a hull loss.
 
prebennorholm
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RE: Ntsb Unhappy With Steps Taken So Far By FAA On 787

Sun Jun 01, 2014 1:10 am

Quoting rg787 (Reply 19):
If I got this thing correctly, we don't know how or why these batteries fail...

Yes and no. We don't know the exact reasons for the 787 battery failures. But we know a whole string of reasons which may cause a Li-Ion thermal runaway, such as:

–Mechanical Damage
–External Short Circuit
–Overcharge
–Too Fast Charge
–Over-discharge
–Too Fast Discharge
–Low Temperature Recharging
–High Temperature Storage
–Manufacturing Contamination or Defect

We also know that minor abuse may cause invisible "damage" which combined with aging may cause severe shrinks of safe operating windows.

And we also know that a thermal runaway destroys the cell making it for most practical things impossible to trace the exact cause by examining the cell.

What we don't know is how to eliminate all possible reasons for a thermal runaway.

Some reasons can be eliminated by battery management systems which are guarantied never to fail, combined with 100% fool proof manitenance procedures. Which isn't so relevant since it is hardly an obtainable goal, and it won't eliminate all reasons.

All sorts of batteries fail one day, that's nothing special for Li-Ion. What is special for Li-Ion is the intensity of smoke and heat generation when it fails.

Some posters have mentioned that the 787 containment system is "overkill". No, it is not. It is exactly designed to contain and exhaust the bad products of a battery failure. No more, no less.

The Yahoo News article is very bad journalism. It's a very long string of badly structured information. Having read it carefully twice I may think that I have figured what dissatisfies NTSB. I think that NTSB wants to tell FAA that they shall be more cautious when making new certification rules for new technologies which are introduced by plane manufacturers. Boeing, Thales and GS-Yuasa obviously failed with the original 787 battery system, but FAA should, according to NTSB, have mandated procedures which would have uncovered their failure.

In fact they could have just googled "li-ion failure mode" and read a small fraction of the wealth of technical documents presented. Then they would have known that Li-Ion thermal runaway events can't be related to IF, but only to WHEN. Li-Ion batteries have been with us for 20+ years, and nothing fundamental has changed in that time frame. Only their operating windows have widened considerably. The first Li-Ion batteries were very restricted especially when talking charge rate and discharge rate, which delayed their introduction into many applications.
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hivue
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RE: Ntsb Unhappy With Steps Taken So Far By FAA On 787

Sun Jun 01, 2014 2:06 am

Quoting PITingres (Reply 17):
Quoting strfyr51 (Reply 15): I'm not sure Why the NTSB needs to KNOW why the batteries failed.
Because it's an unknown.

Originally it was more like an unknown unknown, which is the bane of engineers (what you don't know you don't know).



Quoting Stitch (Reply 21):
It's all about the page hits - this one is closing on 14,000 views, whereas the "Ntsb Safety Recommendation: 787 Battery Issue" thread only has 5000.

I'm the OP on that thread and spent a little while composing the title so as to try to make it sound interesting but not overstate the issue. Actually, I though just mentioning "787 battery" would get everyone's attention. 
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CO953
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RE: Ntsb Unhappy With Steps Taken So Far By FAA On 787

Sun Jun 01, 2014 5:21 pm

Quoting rg787 (Reply 19):
If I got this thing correctly, we don't know how or why these batteries fail, we only know they start a hell of a fire and if not well contained it could bring an airplane down. Well, if I am right, thats a big issue. Yes, things fail and yes, things happen every now and then, the problem with not knowing why and how they happen is that you don't know the limit of it.

Lets say until now, we had fires and other consequences caused by the failing of the batteries that gone until a certain point and that Boeing or whoever uses Li-ion batteries over designed protection measures to prevent this from causing a big catastrophe. Ok, now imagine if beyond the failure of these batteries, something else happens and, combined, these two things can't be controlled or can cause the protection measure not to be sufficient. Well, you have a plane going down.

As people always say, a catastrophe is a combination of failures. To this point we are letting those batteries fail and to this point they haven't caused much of a problem beyond repair, but this could change.

Just my two cents, I am not an engineer nor a mech, so I don't know what else could be caused by those batteries or failures inside the cells, but it could be a problem.

That's my two cents, as well. Not knowing what has caused the failures, yet still allowing the plane to fly, is a game of calculated risk that so far the 787 is winning. Yet, having the cause of the fires still to be unknown still allows the specter of an "unknown unknown" to shadow the plane, which is not optimum.

To put this in terms of U.S. Secretary of Defense Donald Rumsfeld's aphorism about the "known knowns," the "known unknowns" and the "unknown unknowns," the cause of the battery fires is a known unknown, which technically is manageable. Where the unknown unknown comes in is when trying to envision which combination of electrical factors is causing the known unknown, and the potential interplay which could have consequences outside of the immediate battery and affect the airframe's airworthiness in some unknown way ASIDE from the direct effects of a fire.

When the 787 is basically a flying computer, any electrical known unknown or unknown unknown is, IMO, still of high priority to solve. My low-tech '67 Mustang relied so little on the electrical instruments in the dashboard, that I was able to remove the entire instrument cluster and drive around without gauges, with the speedo cable spinning in front of my face, with no effect on the driveability. Try that with a new car. Any risk of electrical malfunction on a flying computer still does matter.
 
tortugamon
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RE: Ntsb Unhappy With Steps Taken So Far By FAA On 787

Sun Jun 01, 2014 9:43 pm

Quoting Stitch (Reply 21):
It's all about the page hits - this one is closing on 14,000 views, whereas the "Ntsb Safety Recommendation: 787 Battery Issue" thread only has 5000.

And now that is closing in on 15,000 views it looks like the title has been changed. Now comes the countdown until the thread falls off of the first page and into a-net obscurity. I give it no more than two days.

Much more responsible title though.

tortugamon
 
strfyr51
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RE: Ntsb Unhappy With Steps Taken So Far By FAA On 787

Sun Jun 01, 2014 11:24 pm

Quoting KELPkid (Reply 16):
IMHO, the only way they are ever going to find out what is going on is to put a datalogger on the battery cells that show intake current, and a datalogger on the charging bus that shows current being fed to the battery, and do this for every plane in operation until another one pops a battery cell, and then corollate the data with the FDR and/or maintenance loggers to figure out what was going on on board the plane at the time

The Battery charging system and the Batteries were NOT tested as a system during the prototyping of the electrical system. they only came together during assembly
This was a mistake and now there are Eicas inputs and outputs to monitor the batteries and charging system from the cockpit So this Might not EVER be in
doubt again but I feel it's too damn Late for the NTSB to re-open the investigation now. They should have had Reps there all
along working hand in hand with Boeing and Uasa to see what the Batteries were doing in REAL time rather than comment After the Horse ran out of the Barn Door.
And Also? Why NOW when the B787 has JUST been awarded 330 minute ETOPS Approval BY the FAA??
It looks like they're covering their Butts After the FACT!!
 
hivue
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RE: Ntsb Unhappy With Steps Taken So Far By FAA On 787

Mon Jun 02, 2014 3:13 pm

Quoting strfyr51 (Reply 26):
but I feel it's too damn Late for the NTSB to re-open the investigation now.

As has been pointed out a number of times, this is just a safety recommendation to the FAA, not a final report. The NTSB's investigation is ongoing.

Quoting strfyr51 (Reply 26):
They should have had Reps there all along working hand in hand with Boeing and Uasa to see what the Batteries were doing in REAL time rather than comment After the Horse ran out of the Barn Door.

The NTSB investigates after the fact (or after the horse is gone if you prefer).
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rg787
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RE: Ntsb Unhappy With Steps Taken So Far By FAA On 787

Mon Jun 02, 2014 6:28 pm

Quoting Stitch (Reply 21):
there was not a "hell of a fire"
Quoting Stitch (Reply 21):
anywhere near being in danger of suffering a hull loss

Hell of a fire or not, in danger of hull loss or not, sometimes a single and simple problem can escalate to something catastrophic. Ok, let's say it is impossible that something serious happens, which is at minimum optimism. The battery problem and its resulting fire made the whole 787 fleet stay grounded for quite sometime. Everytime this happens, and as some in the thread said, it is going to happen to every battery out there, the particular aircraft where it happened is going to be grounded for some time. Aircraft grounded means financial loss, and airlines don't want this, so lets just face it: Boeing needs a better solution for this.
 
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PITingres
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RE: Ntsb Unhappy With Steps Taken So Far By FAA On 787

Mon Jun 02, 2014 7:55 pm

Quoting rg787 (Reply 28):
Hell of a fire or not, in danger of hull loss or not, sometimes a single and simple problem can escalate to something catastrophic.

Well, "can" maybe, but given proper engineering one can be pretty sure it won't. There's only so much energy in a lithium battery even if you burn it in pure oxygen, so containment should be a fairly cut and dried engineering problem. The grounding happened because the designers didn't really expect a runaway and didn't engineer for it.

Quoting rg787 (Reply 28):
Everytime this happens, and as some in the thread said, it is going to happen to every battery out there, the particular aircraft where it happened is going to be grounded for some time

A very small time, on the order of hours I should think, unless there's a parts supply problem and that wouldn't be the aircraft's fault. One might as well say the same about tires.

I'm quite sure that Boeing would like a better solution, the containment is heavy and probably a nuisance. I very much doubt that it's anywhere near the top of the "must fix" list though.


[Edited 2014-06-02 12:58:32]

[Edited 2014-06-02 13:00:00]
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prebennorholm
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RE: Ntsb Unhappy With Steps Taken So Far By FAA On 787

Tue Jun 03, 2014 12:53 am

Quoting PITingres (Reply 29):
I'm quite sure that Boeing would like a better solution, the containment is heavy and probably a nuisance. I very much doubt that it's anywhere near the top of the "must fix" list though.

I don't think so. The Boeing engineers made a good job making a perfect containment and waste exhaust system. Exactly such a system will be needed on all future aircrafts which operate on large Li-Ion batteries, or they won't be certified for flight by EASA, FAA or whoever.

Yes, the weight advantage has mostly evaporated. But Li-Ion offers a lot of other advantages:
- A waiver from the general ban on NiCad isn't needed. (We have seen banned NiCad in other applications replaced by Ni-MH, which isn't suitable for cold weather ops.).
- Avoiding extra cost for disposal of environmentally very unfriendly NiCad when service life expires.
- Li-Ion is likely more reliable - less frequent failures.
- Li-Ion likely offers longer service life.
- Less maintenance - no need to replace battery for "refreshment" to avoid memory effect.
- All R&D resources for future improvements go to Ni-MH and Li-Ion, not NiCad due to the general ban.

With the containment Li-Ion is just as safe as any other battery type (arguably a tiny bit safer). Battery fails, change battery, fly again, game over. Or - depending on circumstances - maybe even: Battery fails, MEL?

I am convinced that Boeing did the right thing when they decided to stay with Li-Ion, and together with FAA and other intellectual resources developed the system needed to make Li-Ion safe. This assumption is backed by the fact that Airbus has announced that they will revert to Li-Ion on the A350. All they need is the exact wording of the EASA and FAA final rulings related to Li-Ion batteries.
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KELPkid
Posts: 5247
Joined: Wed Nov 02, 2005 5:33 am

RE: Ntsb Unhappy With Steps Taken So Far By FAA On 787

Tue Jun 03, 2014 1:08 am

Quoting prebennorholm (Reply 30):
I am convinced that Boeing did the right thing when they decided to stay with Li-Ion, and together with FAA and other intellectual resources developed the system needed to make Li-Ion safe. This assumption is backed by the fact that Airbus has announced that they will revert to Li-Ion on the A350. All they need is the exact wording of the EASA and FAA final rulings related to Li-Ion batteries.

I'm quite certain, though, that Airbus will take advantage of 7 years of intervening battery technology research and use a safer chemistry than Boeing chose for the 787...similar to what Cessna chose for the Citation IV.
Celebrating the birth of KELPkidJR on August 5, 2009 :-)
 
prebennorholm
Posts: 7125
Joined: Tue Mar 21, 2000 6:25 am

RE: Ntsb Unhappy With Steps Taken So Far By FAA On 787

Tue Jun 03, 2014 2:42 am

Quoting KELPkid (Reply 31):
I'm quite certain, though, that Airbus will take advantage of 7 years of intervening battery technology research and use a safer chemistry than Boeing chose for the 787...similar to what Cessna chose for the Citation IV.

Cessna has been playing with Lithium Iron Phosphate (often called LiFe, or A123) as opposed to Li-Ion (Lithium Cobalt Oxide).

That's nothing like 7 years newer or such, both are well over 20 years old. And nothing fundamental has changed in either chemistry during this millenium, only slight gradual improvements of both.

LiFe is less unstable in failure mode than Li-Ion, and may therefore require a thinner containment box. But in principle they are equally toxic. Apart from that LiFe has some 20-25% lower energy density than Li-Ion, meaning that battery of equal capacity is that much heavier. Weight wise they fall nicely in between Li-Ion and NiCad.

Airbus says Li-Ion today. They may change their mind tomorrow. But should they change to LiFe, then it won't mean any fundamental change of safety design aspects.
Always keep your number of landings equal to your number of take-offs
 
XT6Wagon
Posts: 2734
Joined: Tue Feb 13, 2007 4:06 pm

RE: Ntsb Unhappy With Steps Taken So Far By FAA On 787

Tue Jun 03, 2014 2:54 am

Quoting PITingres (Reply 29):
The grounding happened because the designers didn't really expect a runaway and didn't engineer for it.

No, The grounding was due to a media shit storm and political hacks playing cover your butt.

It doesn't help that the NTSB seems to want the laws of physics to not apply to aircraft. ALL batteries in the market suffer "thermal runaway" when they suffer an internal short. Since we use them to store energy why are we suprised that they release energy when damaged? Yet the NTSB hasn't demanded that any other battery technology have *any* of the safeguards that they insist is the mere minimum to operate Li-Ion in an aircraft. God help them when someone tells them what an unsafe nasty dangerous product is a lead acid battery. Overheat or short one of those badboys and boom, explosive hydrogen everywhere, along with corosive acid and potential heat hot enough to light the plastic its case is made from. And almost every car on the road in america has this. Planes atleast are expensive enough to use the somewhat less dangerous but more expensive versions that don't use a liquid electrolyte. Still no one demanded they get full containment vessels when more than one went up in smoke the same week the 787 had issues.

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