Sharing our solution

Tonight during a live webcast from Japan, which you can watch a replay of here, we unveiled the specifics of our permanent solution to the 787 battery issue. That solution is the result of a detailed and rigorous process involving people from around the globe who put in thousands of hours of work—and we’re very confident this solution is the right one.

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The three layers of protection we’ve developed address the factors identified by the Boeing technical team as possible causes of battery failure. The findings were also verified by an independent group of lithium-ion battery experts from a number of industries, universities and national laboratories. Let’s walk through each of them.

Enhanced Production Controls and Operating Processes

The first layer of improvements is taking place during the manufacture of the batteries in Japan. Boeing teamed with Thales, the provider of the integrated power conversion system, and battery maker GS Yuasa to develop and institute enhanced production standards and tests to further reduce any possibility for variation in the production of the individual cells— as well as the overall battery.

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Enhanced production standards are built into the new battery design.

Four new or revised tests have been added to screen cell production, which now includes 10 distinct tests. Each cell will go through more rigorous testing in the month following its manufacture including a 14-day test during which readings of discharge rates are being taken every hour. This new procedure started in early February and the first cells through the process are already complete. There are more than a dozen production acceptance tests that must be completed for each battery.

We’ve also decided to narrow the acceptable level of charge for the battery, both by lowering the highest charge allowed and raising the lower level allowed for discharge. Two pieces of equipment in the battery system - the battery monitoring unit and the charger— are being redesigned to the narrower definition. The battery charger will also be adapted to soften the charging cycle to put less stress on the battery during charging.

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Improved Battery Design Features

Changes inside the battery will help reduce the chances of a battery fault developing and help to further isolate any fault that does occur so that it won’t cause issues with other parts of the battery.

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To better insulate each of the cells in the battery from one another and from the battery box, two kinds of insulation will be added. An electrical insulator is being wrapped around each battery cell to electrically isolate cells from each other and from the battery case, even in the event of a failure. Electrical and thermal insulation installed above, below and between the cells will help keep the heat of the cells from impacting each other.

Wire sleeving and the wiring inside the battery will be upgraded to be more resistant to heat and chafing and new fasteners will attach the metallic bars that connect the eight cells of the battery. These fasteners include a locking mechanism.

Finally, a set of changes is being made to the battery case that contains the battery cells and the battery management unit. Small holes at the bottom will allow moisture to drain away from the battery and larger holes on the sides will allow a failed battery to vent with less impact to other parts of the battery.

New Battery Enclosure

The battery case will sit in a new enclosure made of stainless steel. This enclosure will isolate the battery from the rest of the equipment in the electronic equipment bays. It also will ensure there can be no fire inside the enclosure, thus adding another layer of protection to the battery system. The enclosure features a direct vent to carry battery vapors outside the airplane.

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New titanium fixtures are being installed in the electronics equipment bays to ensure the housing is properly supported.

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The battery will now sit inside a new enclosure made out of stainless steel. A stainless steel panel is seen on the right.

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Already testing

With the FAA’s permission, we’ve already started testing to gain FAA approval of the battery enhancements. During engineering testing, which occurs prior to certification testing, the team demonstrated that the new housing could safely contain a battery failure that included the failure of all eight cells within the battery. The “ultimate” load is the equivalent of 1.5 times the maximum force ever expected to be encountered during a battery failure. The housing easily withstood this pressure and did not fail until the pressure was more than three times the ultimate load.

Through another test, the team demonstrated that fire cannot occur within the new enclosure. Its design eliminates oxygen, making the containment unit self-inerting. Inerting is a step above fire detection and extinguishing as it prevents a fire from ever occurring. The design also vents all vapors by venting directly outside of the airplane rather than into the equipment bay.

As we’ve said before, we’ll use two 787s for ground and in flight testing of this solution. We’re also simultaneously moving out on an effort to resume deliveries.

During the webcast, Boeing Commercial Airplanes president and CEO Ray Conner said he spoke for all 170,000 Boeing employees when he said our number one priority is the safety of everyone who flies on our airplanes. I couldn’t agree more—and look forward to being one of the first people back on board the 787 when it takes to the skies again.

Comments (8)

Tim K (Ont Can.):

It is encouraging to see all this effort going in to getting the 787 back into service but this leads me to one silly question. It looks like there are thousands of highly educated and trained people, a number of companies and all the world's governing aviation agencies trying to figure out what happened or what the "root cause" of this problem is and it still has everyone stumped.

The 787 is currently in production, you can see every component separately, while being manufactured and before installation, every person who designed these systems is still alive to question , all the blueprints are available to be examined, this is not like a team of scientists discovering some dinosaur bones and trying to figure out how it died everything is still available to be examined and yet the root cause escapes discovery.

I have faith and trust in both Boeing and the FAA in doing the right thing but this still leads me to this question and concern... Just how complicated is the 787's electrical architecture that has everyone still scratching their heads and proceeding with these battery modifications without knowing the root cause really that wise?

Thiagarajan K Rengasamy (Kuala Lumpur, Malaysia):

Congratulations to the Boeing team for the comprehensive solution. Good Luck and lets get the 787s airborne again

Nandakumar Ravindran (Rockford, Illinois, USA):

Congrats Boeing team for the amazing solution. 787 is the greatest airplane. I feel proud to be the part of 787.

George M (Virginia):

I am so very proud of the Boeing team... this is the kind of American ingenuity and teamwork that produces a world-class product. As a Boeing shareholder and enthusiast, I applaud your efforts and look forward to beating Airbus at every turn!

Norman (Long Beach, CA):

Its been a hard and long road and there are more miles to go but I am confident in the engineering team at Boeing. It wont be long until we will the the 787 in her rightful place in the sky.

Martin Horowitz (Long Beach, CA):

I haven't seen any answer to the question about the internal battery separator(layer of material between the anode and cathode of the Battery) type anywhere. Does the Battery use a ceramic type separator

If not a battery the size of GC Yuasa cell could have a punch through without an overcharge condition.

If the battery compartment on the plane is not thermally well regulated the Boston Scenario MAX Cold, landing shock , max discharge to start the APU followed by recharge would cause a separator failure in much less than the rated battery life.

Note I am the delveloper of the C-17 Awods diagnostic system and former PHM lead on the NGC BAMS UAV.

Hugh Coleman (Kelso, Washington, USA):

We know more than is necessary about what the batteries in question did. Those that say we should get to the root cause seem to forget the process destroys evidence by it's nature. There is much more to investigation than being able to actually see something recreated or to recreate a problem. I would suggest we look at the battery cells that are being rejected by the new tests and see what they tell us before they self destruct.

Gabriel (Buenos Aires, Argentina):

I have doubts.

I fully agree that finding and addressing all the possible causes and not just the root cause is the best course of action even if the root cause was found, and the only possible one when the root cause is not found.

I also feel very confident that the containment actions (spacers between cells, new "bulletproof" enclosure, etc.) are very effective the keep the plane safe in the event of a cell or battery failure.

That said, if the root cause is not identified, there is always the possibility that it is not among all the potential causes identified, and hence not addressed.

At the same time, I have the (maybe irrational) feeling that root cause may be intrinsic to the technology, design and/or manufacturing, and very little seems to have been done to address that, other than non-disclosed improvements to the manufacturing process (doesn't sound like a real breakthrough) and enhanced tests, which is again a containment and not a correction and no test is a 100% effective screen, especially when you screen for the fault and not for the cause which is still unknown. In fact, if the new test are discarding more batteries, as implied in the post above, that might be an indicator of the (not so good) capability and robustness of the design and manufacturing process, even after the improvements.

So in my (still irrational) nightmares, I fear that in the future we might have a failure rate that is similar to that of the past. Now extrapolate these 2 failures in one year, knowing that the fleet size by now is maybe 5% of what it will be in a few years, and we are talking of dozens of these failures per year which, while safely contained, can be worrisome from a commercial and public image for Boeing and its customers, the airlines.

Yes, I know and concede, it's just a pessimistic scenario based on incomplete information, feelings, fears and nightmares and not on data and evidence, but at the same time I can't find data and evidence to give me a very high confidence that this scenario won't happen.

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