Problems with the Dreamliner battery

[Dotini]

Wow, that is really bad news for Boeing if they can't completely nail this problem down to a fixable root cause. I sure hope Boeing has a 'Plan B' that won't take a year of downtime to qualify a new electrical sub-system.

Boeing management is currently feuding with its engineers. Perhaps a lengthy strike could allow force majeure to be invoked over the delivery schedule and any late delivery penalties.

We know the NTSB and FAA are looking not only into the specific battery woes, but also the design, manufacturing, and underlying certification processes are all up for review. In my humble opinion, all this will take roughly 18-24 months to be resolved.

Since industry analysts are well aware of these issues, it's remarkable how well the price of Boeing stock is holding up.

Respectfully submitted,
Steve

 

[nsaspook]

http://seattletimes.com/html/businesstechnology/2020373450_boeing787xml.html?syndication=rss

The initial redesign includes a fireproof battery box, made of titanium or steel, several sources said. That will seal the cells, keeping moisture out and flames in.

It also includes a venting system that will directly evacuate to the outside any vapor and liquid flowing from the battery.

In the two recent battery overheating incidents, flammable liquid and vapor sprayed out of the battery and across the electronics bay where the battery sits, before reaching an outflow valve.

Longer term, the battery box will be enlarged to provide more separation between the battery’s eight cells, several sources said.

That will help ensure that overheating of one cell doesn’t spread to others — a so-called “thermal runaway” that occurred in both recent incidents.

The battery control system will have sensors to monitor the temperature and voltage of each individual cell rather than the battery as a whole, one source said.

And the same source said engineers are also working on using an inert gas such as halon or nitrogen to expel the oxygen generated when a battery overheats.

 

[OmCheeto]

... and any cowboy will tell you : "Always drink upstream of the herd".

old jim

So how much is this fiasco going to cost all of the parties involved?

And all because of an insignificant, pitiful battery.

This strikes me as pathetic beyond words.

 

[Dotini]

We will know a little bit more by this evening's late news; but a "no" vote and strike authorization does not mean that a walkout is imminent. IF Boeing management doesn't agree to return to the bargaining table by the end of February then something will happen after the 1st week of March. A strike is a get-out-of-delivery-delay-jail free card, BUT I'm not sure that a strike trumps an FAA grounding order.

http://seattletimes.com/html/businesstechnology/2020373450_boeing787xml.html
Boeing has short and medium term plans. Real pain will ensue beyond 9 months.

Meanwhile, back in Everett, 787s are stacking up at the rate of 4 per month and 1 per month in South Carolina.

The original 787 Li-ion battery was certified on the basis that there would only be one "smoke event" per 10 million hours of operation. The 50 787s delivered only have about 50K hours of operation as of January 16, 2013, and have experienced 2 "smoke events".

Not root cause yet but little buggers called dendrites are suspect: http://seattletimes.com/html/businesstechnology/2020342832_787probexml.html

Respectfully,
Steve

 

[AlephZero]

Boeing has short and medium term plans.

The short term plan seems to be "well, we haven't any idea what caused the problem, but hey, let's put the battery in a metal box with a pipe venting overboard to let the smoke out".

That must be a good plan. It's taken "hundreds" of Boeing engineers working "round the clock" to come up with it, according to their press releases.

Even that will take 3 months to certify and retrofit, assuming the FAA are prepared to sign it off. But I can't see the FAA signing anything off until the NTSB have issued a formal investigation report. The only promise date for that is "maybe we can issue a preliminary report by the end of February," but that will only be a record of the facts, not an analysis of the actual problem.

I'm inclined to believe LOT airline's time estimates (October at the earliest for a fix). They don't have anything to lose by being honest.

 

[jim hardy]

http://seattletimes.com/html/businesstechnology/2020373450_boeing787xml.html?syndication=rss
"...The battery control system will have sensors to monitor the temperature and voltage of each individual cell rather than the battery as a whole,..."

What ? One sensor?
As sensitive as these things are to temperature,
IMHO it's very bad judgement to accept the time lag for temperature to transit beween an overheating individual cell and a single sensor that's monitoring the whole battery.
Somebody should have kaboshed that.
Those sensors need to be in intimate contact with their respective cells. Inside them if possible.

If that's what really happened, it is a symptom of too much delegation of design responsibility . And inadequate review.

But it's hard to believe.
So I'll wait on more info about the monitoring & control system architecture.

 

[nsaspook]

I think the FAA and the NTSB believes Boeing played them for fools with the battery special conditions and will force a compete redesign with a different battery type before the plane will fly again. Just containing the fire is not really a option when you need the battery to fly the plane safely.

http://www.evworld.com/focus.cfm?cid=15

The FAA is on the hot seat. Five years ago, they accepted Boeing’s arguments and granted permission to use lithium-ion batteries on the Dreamliner, “if potential fire is contained and fumes vented”. They now have a dilemma – hurting an important domestic industry by doing their job, or becoming discredited if another problem occurs.

 

[OmCheeto]

hmmmm

After offering to help Boeing with its lithium-ion battery problems, Elon Musk is somewhat raising the stakes. Musk, who heads both Tesla Motors and space exploration company SpaceX, has now called the batteries in the Boeing 787 "inherently unsafe" in an e-mail to trade publication Flightglobal.

ref

I've often whined about them using AA sized cells in electric cars. I just found out why they do that, on purpose:

For example, with seven thousand 18650 cells the surface area is roughly 27 square meters. If there were an imaginary set of 20 much larger cube-shaped cells that enclosed the same volume, the surface area would be only 3.5 square meters, more than seven times smaller. Surface area is essential to cooling batteries since the surface is where heat is removed; more is better. Also, because of their small size, each cell is able to quickly redistribute heat within and shed heat to the ambient environment making it essentially isothermal. This cooling architecture avoids “hot spots” which can lead to failures in large battery modules.

ref

I guess it made me crazy imagining trying to connect 7000 cells, or trying to locate one bad cell out of 7000.

 

[Ptero]

Those sensors need to be in intimate contact with their respective cells. Inside them if possible.

That won't work. At least, it will not warn of a problem until the battery is in runaway mode. Why? Because the shorts start at points measured in sub-cubic mm volume. Sure, the sensor might pick up a rising temp indication, but in preventing runaway thermal episodes, you are depending on luck, not engineering.

Amazingly, Boeing, in full recognition of this fact and desparate to get the Dreamliner fleet flying again, proposed to the FAA a new containment box with stainless steel walls nearly one-half an inch thick with a tube venting super-heated gas (plasma) outside the plane at locations at the cockpit and near the trailing edge of the wings. I read this in the Seattle paper, and the reporter speculated that this was not really a good idea because the battery could possibly vent flames during fueling.

And when are the likely times for a runaway condition? On the tarmac during fast charging. I suspect this is exactly what happened to the JAL B-787. But that is not the most serious example the FAA has to deal with. The B-787 that landed with the battery box on fire in Japan came close to erupting into flames in the cockpit IN THE AIR. This could have brought down the plane, killing everyone on board.

I am perplexed at Boeing's response. Obviously, at this juncture, the Li-Cobalt batteries have to be replaced with some other safer type. All safer types require greater volume to produce an equivalent output. The space engineered and built for the box is not large enough so a nightmare retrofit will be necessary. This is a solvable problem but Boeing is in a serious pickle here, on one hand losing millions per day and on the other, having originally provided to the FAA the data and formal assurances on the Li-Co batteries. Not only are they eating crow and losing money, but they have embarrassed the FAA and likely also pissed them off, so a quick return to the skies for the Dreamliner is out of the question in the absence of political corruption (which is not unheard of) or a jiggered peer review (probably harder to pull off).

What is wrong with Boeing? I keep asking myself this. The Li-Co problem was well known. There is no excuse. Has Boeing done something to make their engineers less capable, as NASA did on the loss of a billion-dollar Mars probe when an engineer confused imperial with metric measurement? Was it brought about, perhaps, by government policy, such as hiring mandates? The Boeing incident is even more peculiar because many engineers were involved in this decision. It was not just one who made the mistake, as in the NASA case. I don't know how badly this will hurt Boeing. It will be a deep wound. The only thing I'm certain of is that we taxpayers will end up paying for it in some future military contract.

 

[Ptero]

Digging, I found this. Not sure what to make of it. For now, a coincidence.
-----------------
Updated Boeing Statement on 787 Dreamliner ZA002 Incident

EVERETT, Wash., Nov. 11, 2010 /PRNewswire/ -- Boeing continues to investigate Monday's incident on ZA002. We have determined that a failure in the P100 panel led to a fire involving an insulation blanket. The insulation self-extinguished once the fault in the P100 panel cleared. The P100 panel on ZA002 has been removed and a replacement unit is being shipped to Laredo. The insulation material near the unit also has been removed.

Damage to the ZA002 P100 panel is significant. Initial inspections, however, do not show extensive damage to the surrounding structure or other systems. We have not completed our inspections of that area of the airplane.

The P100 panel is one of several power panels in the aft electronics bay. It receives power from the left engine and distributes it to an array of systems. In the event of a failure of the P100 panel, backup power sources – including power from the right engine, the Ram Air Turbine, the auxiliary power unit or the battery – are designed to automatically engage to ensure that those systems needed for continued safe operation of the airplane are powered. The backup systems engaged during the incident and the crew retained positive control of the airplane at all times and had the information it needed to perform a safe landing.

Molten metal has been observed near the P100 panel, which is not unexpected in the presence of high heat. The presence of this material does not reveal anything meaningful to the investigation.

Inspection of the surrounding area will take several days and is ongoing. It is too early to determine if there is significant damage to any structure or adjacent systems.

As part of our investigation, we will conduct a detailed inspection of the panel and insulation material to determine if they enhance our understanding of the incident.

We continue to evaluate data to understand this incident. At the same time, we are working through a repair plan. In addition, we are determining the appropriate steps required to return the rest of the flight test fleet to flying status.

Boeing will continue to provide updates as new understanding is gained.

Contact:

Lori Gunter
787 Communications
+1 206-931-5919

SOURCE Boeing
http://boeing.mediaroom.com/index.php?s=43&item=1515

 

[jim hardy]

And when are the likely times for a runaway condition? On the tarmac during fast charging.

ptero - that was my point. Batteries warm up during charge and that needs to be sensed early not late. One overtemperature sensor for the whole pack(if indeed that's what they did) would be, well, indicative of amateurism. One cannot assume all cells are equal tempereature, a single sensor will only tell you that one cell is afire or nearly so and about to spread...
My reactor had fifty-one thermocouples immediately above core to monitor for local temperature anomalies. That's in adition to redundant bulk temperature sensors for control and protection.

but i am of the same thoughts as you on this point - airplanes should use a safer battery chemistry.

old jim

 

[Ptero]

Jim, I was pointing out that, based on the literature I have read, heat sensors are not effective in finding the point of failure inside a Li-Co batttery. Nothing is. The only way to tell what happened is after the fact, with an "autopsy," if you will. But sensors will only provide an average temperature while likely missing entirely the "hot spot" as it develops.

My point is that people can easily be misled into thinking that temperature sensors on Li-Co batteries can provide the same kind of safety assurance they have demonstrated on metal-hydride, nickle-cadmium and even lithium-magnesium types. But Li-Co is a strange beast. When they work, they work really well and lull you into a false sense of security. It appears to me that we have gotten way ahead of ourselves in thinking that the larger ones can be managed safely.

Part of this false sense of safety comes from the design of thermal-triggered open circuits designed into each cell. A good discussion begins here around page 25 of Lithium-Ion Batteries Hazard and Use Assessment - Final Report:

http://www.nfpa.org/assets/files/PDF/Research/RFLithiumIonBatteriesHazard.pdf

Unfortunately, the reliability of this feature does not prevent a thermal runaway if it is in progress, but rather is intended to prevent too rapid discharge or charge conditions from damaging or degrading the battery.

 

[jim hardy]

Thanks ptero

you posted that NFPA paper a few pages back and it IS an eye opener.
One could surround that battery with extremely sophisticated monitors and still have it go pyrotechnnic.

I am still curious just how far Boeing's "battery charger subcontractor" went with his monitoring.

Unfortunately, the reliability of this feature does not prevent a thermal runaway if it is in progress, but rather is intended to prevent too rapid discharge or charge conditions from damaging or degrading the battery.

Agreed, with that chemisty it likely just 'shuts the barn door after the horse has gone.'

old jim

 

[Ptero]

This morning, Aviation International News published a story about lithium ion battery types being incorporated into business jets. It appears that several new models from various manufacturers have backed away from lithium. Last year, for instance, Gulfstream had designed in lithium power for its G650 but recently redesigned the system in favor of nickel-cadmium. AIN also says it was told by Cessna on October 18, 2012 that the new Citation X would be fitted out with dual lithium battery packs, but the necessary FAA special order has still not been issued. Cessna's Soverign and CJ4 have also received FAA clearance for lithium batteries but following a lithium iron-phosphate battery fire onboard a CJ4 during fast-charging the FAA issued this Airworthiness Directive, effective November 1, 2011:

We are adopting a new airworthiness directive (AD) for certain
Cessna Aircraft Company (Cessna) Model 525C airplanes. This emergency
AD was sent previously to all known U.S. owners and operators of these
airplanes. This AD requires replacing certain lithium-ion batteries
installed as the main aircraft battery with either a Ni-Cad or a lead
acid battery. This AD was prompted by a report of a battery fire that
resulted after an energized ground power unit was connected to one of
the affected airplanes equipped with a lithium-ion battery as the main
aircraft battery. We are issuing this AD to correct the unsafe
condition on these products.

The Spectrum Aeronautical S-40 has also recently canceled its plans for lithium batteries. And all this pales in the face of the huge Airbus redesign of its newest transport which drops Li-Ion in favor of bulkier but safer Ni-cadmium. See "Airbus scraps troubled battery for A350".

Now, I have been told by many people, some expert, who flatter themselves that they are knowledgeable in this area, that automotive lithium iron-phosphate batteries are safe and do not share the negative qualities of lithium cobalt-oxide batteries. However, "http://www.nfpa.org/assets/files/PDF/Research/RFLithiumIonBatteriesHazard.pdf" states that all types of lithium batteries can be subject to thermal runaway. This is not exactly what we were told following the Chevy Volt lithium iron-phosphate battery fires. The NHTSA closed the investigation of the Chevy Volt after blaming one fire on loss of coolant, stating "the agency’s investigation has concluded that no discernible defect trend exists." Two other fires were blamed on faulty charging systems. One of these fires resulted in the loss of an entire home and the other in the loss of a garage, in addition to both Chevy Volts. A new Fisker Karma EV was also blamed for burning down a home in Texas, while another self-immolated in California. Nether were plugged in.

The CJ4 fire was blamed on improper charging using certified equipment. Although the FAA blamed the mechanic for following improper procedure, it nonetheless issued the AD forcing the replacement of the lithium iron-phosphate batteries. (A lead-acid replacement was chosen by the operator.)

I ask again, what is going on? When the problem is human error, the FAA typically issues a procedural directive and additionally may incorporate some fail-safe devices such as switch locks. It does not force replacement of the entire system. This appears unusual and contradictory when compared to the NHTSA action where no system replacement was mandated. And why was the NTHSA investigation of the Chevy Volt fires fast-tracked, then suddenly closed when FAA investigations can go on for years, as mentioned a few posts back?

(Another curious point is that the CJ4 lithium iron-phosphate battery was manufactured by A123 Systems, which was readying for assembly of the Chevy Volt battery packs for this year when it suddenly went bankrupt.)

See this article by the same AIN reporter for more.

See this list of battery fires in NA from the FAA.

_________________
"it ain't what you don't know
that gets you in trouble,
it's what you 'know' that ain't so."
-- Mark Twain

 

[nsaspook]

A human interest side of the story. http://www.reuters.com/article/2013/02/28/uk-boeing-dreamliner-pilots-idUSLNE91R00920130228

The pilots Reuters spoke to said the 787 is easy to fly, though one was wary about any quick fix to the battery problems.

"Personally, I'm not satisfied by Boeing's proposals as the fundamental cause has not been identified," he said. "I want to fly, but I won't until it's certain the aircraft is safe."

As they wait for the all-clear, pilots' routines have been turned upside-down.

One of the pilots, used to constant jet-lag and skipping meals because of his flight schedule, now eats three home-made meals a day. He's put on weight and says his uniform has become a little tighter. For now, he's playing more sport and reviewing his flight manuals. The second pilot said he's keeping busy with gardening and DIY projects around his home. He also checks regulators' websites for updates on the 787 investigations.

 

[Ptero]

Fun with lithium.

https://www.youtube.com/watch?v=BliWUHSOalU

And in http://www.reuters.com/article/2013/03/02/us-boeing-787-oversight-idUSBRE92104W20130302, a description of "an occupation with a built-in conflict of interest" is interesting:

The U.S. Federal Aviation Administration (FAA) said it would no longer directly manage routine inspection of design and manufacturing. Instead, it would focus on overseeing a self-policing program executed by the manufacturers themselves through more than 3,000 of their employees assigned to review safety on behalf of the FAA. These so-called designees had existed for decades, but the FAA had vetted and controlled them. Under the new system, companies chose and managed them, to the point where the FAA even had trouble rejecting those they felt were unsuitable for the job, according to one government watchdog. As the drama of the overheating lithium-ion batteries on the Boeing 787 Dreamliner unfolds, that relationship is coming under intense scrutiny.

Wasn't this what we did with the banks?

"They knew they had problems. They just said 'OK.'" -- former DOT Inspector General Schiavo

 

[AlephZero]

Fun with lithium.

https://www.youtube.com/watch?v=BliWUHSOalU

Back in the 1970s I knew a guy who worked for a specailist air-conditioning company. He was working on aircon for manufacturing some military devices using Lithium (I don't know if they were Li batteries back then - might have been some sort of pyrotechnics).

The "fun" part was keeping the entire factory permanently below 1% RH, to avoid the reactions with water as in the video. And moving the entire operation from the UK to the middle of a hot desert was not an acceptable option!

 

[Ptero]

The Boston Globe reports that it took firefighters 40 minutes to put out the lithium battery fire on the JAL Dreamliner in Boston. One might think this would be something to avoid happening in the air, perhaps over the Pacific Ocean.

But it now looks to me like we are witnessing one of the greatest kludges in the history of aviation taking place before our eyes. The engineers who said the lithium cobalt-oxide battery packs would work were wrong. They don't work. They catch on fire. And they come NOWHERE NEAR their safety expectations and MTBF. But they are part of a mission-critical system that they really can't change, the bean counters say, so they got another team of engineers to build a heavy stainless steel armor box around the problem so that when it burns up or explodes or whatever, the flames and smoke will hopefully be vented outside the plane.

This is not how engineering was done in the past on American equipment, not to mention American aircraft. I just read in the Indian press that the Indian Dreamliners will be flying with this FAA-approved kludge next month. What could go wrong?

Melting point of new stainless steel box: 2750 F
Melting point of old titanium box: 3040 F

This is how it's done, kids. This is how perfectly good airplanes fall out of the sky in flames. The engineers say it will work and they are proved wrong.

Oh, and there's this:

Swelling found in second battery on Japanese Dreamliner

 

[AlephZero]

Boeing are busy spamming the media about how fast this will get fixed. Google "787" for links.

The FAA made a statement last week contradicting them:

Industry and federal officials said the agency had rejected a request from Boeing to set a date to begin checking the solutions on flights by Boeing’s test aircraft.

Laura J. Brown, an agency spokeswoman, said Tuesday that “reports that we are close to approving test flights are completely inaccurate.”

http://www.nytimes.com/2013/02/27/business/regulators-await-boeing-battery-results.html?_r=0

But "don't believe everything you read in a newspaper" is hardly a new concept!

 

[Ryuk1990]

Elon Musk (co-founder of Tesla Motors and SpaceX) had this to say about the Dreamliner battery.

“The 787 batteries have very large cells, the battery cells are very big and they’re quite close together and there’s not enough insulation between the cells. So if one cell goes into thermal runaway and catches on fire, it’s going to cascade into the other cells.

The approach we take at Tesla and SpaceX is we have smaller battery cells with gaps between them, and we make sure that if there’s a thermal runaway event which creates quite a bit of fire and smoke that it directs that fire away from other cells, so you don’t have this domino effect….

The long term solution for having a battery pack that’s reliable and safe and lasts a long time is to reduce the size of the cells, and have more cells that are smaller and have bigger gaps and better thermal insulation between the cells.”

http://blogs.wsj.com/corporate-intelligence/2013/02/26/elon-musks-solution-to-boeings-battery-problem/

 

[jim hardy]

Does anyone know what method is used to cool the 787 battery pack?

Chevy Volt apparently has liquid coolant system for the battery that can tap into the car's passenger compatrment refrigeration system... they limit their battery to 104F.

I've not seen mention of a coolant system, and on what few pictures I've seen i expected to see connecting pipes for forced air or liquid but didn't..http://www.designnews.com/document.asp?doc_id=257987&cid=NL_Newsletters+-+DN+Daily&dfpPParams=ind_184,industry_aero,aid_257987&dfpLayout=article

also there's a low temperature threshold below which they shouldn't be charged.

Just curious,... 787 battery temperature control is a subject i haven't stumbled across.

http://www.coolingzone.com/index.php?read=508&onmag=true&type=marketing

 

[jim hardy]

here's some interesting stuff

manufacturer's sales sheet for the charger
http://www.securaplane.com/products/power-conversion

their patent on the 'inflection point' charging algorithm (you need a TIFF reader)
http://patimg2.uspto.gov/.piw?docid...1=5780994.PN.%26OS=PN/5780994%26RS=PN/5780994

a diagram of the battery enclosure
http://leehamnews.wordpress.com/2013/02/19/787-battery-diagrams/


old jim

 

[AlephZero]

If you thought this story couldn't get any stupider...

Boeing's Ray Conner is now claiming it "would have been quicker" to fix the problem by chanigng the battery technology, but Boeing aren't going to do that.

http://www.ft.com/cms/s/0/9fdb29d8-8500-11e2-88bb-00144feabdc0.html#axzz2MigWUb5E

 

[Dotini]

Meanwhile, back at the suppliers, and on the factory floor, it's full speed ahead. Boeing has a strong business plan.

http://www.bizjournals.com/seattle/news/2013/03/04/boeings-ray-conner-confident-on-787.html?page=3
Currently the plan is to increase 787 production to seven monthly in mid-year, and then 10 monthly by the end of 2013.

“That could change if something goes sideways with FAA or something like that, but we’ll cross that bridge if we come to it,” Conner said. “Right now we’re on track to break to seven, and then go to 10.”

Respectfully,
Steve

 

[Ptero]

What could go wrong?
__________________

http://www.foxnews.com/leisure/2012...tery-pack-reportedly-caused-gm-lab-explosion/
__________________

In my experience, people who know what they are doing don't get hurt.

On the other hand, people who don't know what they're doing create situations where people get hurt. I just hope we don't see something like this happen in the cockpit of a passenger transport at 30,000 over the Pacific.

 

[nsaspook]

http://www.king5.com/news/local/FAA-delaying-approval-of-788-battery-fix-195778871.html

SEATTLE - KING 5 News has learned that the FAA is not yet ready to greenlight Boeing’s plan for a 787 fix. A source familiar with negotiations between Boeing and the FAA says the sides are still trying to figure out if Boeing should be given credit for certain battery tests already performed.

FAA approval, which was hoped for as early as today, is now not expected until next week at the earliest.

Credit, even if the plan was 100% solid (dubious) I would make them repeat every test with a randomly picked plane including a full charge single cell thermal runaway test.

 

[0xDEADBEEF]

Meanwhile, back at the suppliers, and on the factory floor, it's full speed ahead. Boeing has a strong business plan.

http://www.bizjournals.com/seattle/news/2013/03/04/boeings-ray-conner-confident-on-787.html?page=3
Currently the plan is to increase 787 production to seven monthly in mid-year, and then 10 monthly by the end of 2013.

“That could change if something goes sideways with FAA or something like that, but we’ll cross that bridge if we come to it,” Conner said. “Right now we’re on track to break to seven, and then go to 10.”

Respectfully,
Steve

But those are "batteries not included"

 

[AlephZero]

The NTSB Interiim Factual Report on the Boston incident:
http://www.ntsb.gov/investigations/2013/boeing_787/interim_report_B787_3-7-13.pdf

I just love section 1.9:

When smoke is detected, the avionics cooling function is designed to exhaust smoke overboard through fans in the cooling ducts and changing supply valve positions (and the use of differential pressure if the airplane is in flight). During this incident, the supply valves (which are electrically driven) lost electrical power after the APU shut down because the APU was the only source of electrical power being used at the time.

Translation: the fans to prevent smoke from the battery getting into the cabin didn't work, because they were powered by the battery that had caught fire.

You couldn't make this stuff up

 

[nsaspook]

Complete Docket: http://dms.ntsb.gov/pubdms/search/hitlist.cfm?docketID=54251&CFID=344434&CFTOKEN=65836259

Note: "Airworthiness Factual Report of Group Chairman"

 

[nsaspook]

http://www.aviationweek.com/Article.aspx?id=/article-xml/AW_03_18_2013_p28-559071.xml

Boeing and 787 operators around the world may be breathing easier following U.S. Federal Aviation Administration approval of the manufacturer's battery system redesign certification plan, but the hard work is only just beginning,

As the grounding of the 787 stretches into an unprecedented 10th week, Boeing has been told by the FAA the aircraft will only be cleared to return to service after the manufacturer conducts “extensive testing and analysis to demonstrate compliance with the applicable safety regulations and special conditions.”
...
The NTSB has announced plans to hold a forum and investigative hearing in April to review the battery's technology, safety and process used in its certification. The agency's investigation found—among other things—no record of the final production-standard charging system having been tested with the actual GS Yuasa-made battery. According to the NTSB report, Securiplane, the charging system developer, tested the unit with a simulated electric load instead of an actual battery. The company apparently took this precaution after having earlier suffered a fire at its facility during battery testing.