Special ‘task force’ studied lithium-ion batteries long before JAL 787 incident

A special task force was studying issues relating to the use of lithium-ion batteries in airliners long before the January 2013 Japan Air Lines fire. The effort began in 2008 and it met in December 2012, one month before the JAL fire.

Boeing, the FAA, Embraer, Airbus, GS Yuasa, American Airlines and ALPA are just a few who participated in these meetings, according to documents.

Randy Tinseth, VP Marketing for Boeing, referred to the group when he discussed the FAA approval to proceed with the Boeing plan to fix the 787 battery issues in his blog, here.

Tinseth writes:

The certification plan calls for a series of tests that show how the improved battery system will perform in normal and abnormal conditions. The test plans were written based on the FAA’s standards as well as applicable guidelines published by the Radio Technical Commission on Aeronautics (RTCA), an advisory committee that provides recommendations on ways to meet regulatory requirements. The RTCA guidelines were not available when the original 787 battery certification plan was developed.

We asked Boeing what the document was that Tinseth referred to above: it is a document numbered DO-311. There are a number of documents at RTCA containing the reference to DO-311.

DO-311 is described by RTCA as:

DO-311, Minimum Operational Performance Standards for Rechargeable Lithium Battery Systems
 
Issued 03-13-08
 
Prepared by SC-211
 
This document contains Minimum Operational Performance Standards (MOPS) for rechargeable Lithium battery systems to be used as permanently installed power sources on aircraft. Compliance with these standards is recommended as a means of assuring that the Lithium battery will perform its intended function(s) safely, under conditions normally encountered in aeronautical operations. These standards apply to the chemical composition, cell size, cell construction, cell interconnection methods within batteries, venting provisions, operational and storage environments, packaging, handling, test, storage and disposal of rechargeable Lithium batteries, installed separately or in avionics equipment aboard aircraft.
.

This recent document notes that there had not been, as Tinseth wrote, there had not been standards for the current uses of lithium-ion batteries:

Standards for non-rechargeable Lithium and for large rechargeable Lithium batteries exist in current RTCA documents; however certification guidance for small to medium size rechargeable lithium batteries and battery systems that are permanently installed on aircraft does not currently exist. The aviation industry is seeing increased use of these small and medium sized rechargeable Lithium batteries in Avionics and Cabin Systems equipment. Certification guidance addressing these batteries and systems will enable a more efficient and standardized certification approach across the industry.
.
The document also reveals that Boeing had been in touch with Embraer and Airbus, but no detail is provided. Guidelines from the committee are due this month.
.
This 2011 document contains a PPT presentation beginning on PDF page 10 that contains a lot of information about testing, the issues, etc., all pre-dating the January JAL fire. PDF page 45 specifically raises the concern about an internal short.
This December 2012 document is one month before the JAL fire.

31 Comments on “Special ‘task force’ studied lithium-ion batteries long before JAL 787 incident

  1. This problem will be solved. It has taken Boeing many weeks working with engineers and suppliers to come up with a solution. Considering the 787 is a next generation aircraft incorporating many new systems and designs, it appears to have been a success apart from the battery issue.
    The plan to keep the production going was the right decision as the demand for the 787 is very good and the modifications to the battery issue can be done on the finished frames.
    Hopefully a few years from now when hundreds of these fuel efficient are flying for the worlds leading airlines, the battery issue will be a distant memory and work can proceed on the 777-9X and the 787-10.

  2. “Standards for non-rechargeable Lithium and for large rechargeable Lithium batteries exist in current RTCA documents; however certification guidance for small to medium size rechargeable lithium batteries and battery systems that are permanently installed on aircraft does not currently exist.”

    If that certification guidance had existed at the time the 787 battery system was certified Boeing would probably not have had to go through this ordeal.

    • That probably would have transfered the ordeal to certification time. No rubber stamping.

  3. As far as I know, no such standards exist. It will take a few more years before they are fully agreed upon and enforced.

    • It is my understanding that although it did not exist at the time of the Dreamliner certification, it does exist today. And if I am not mistaken that is what RTCA DO-311 is all about.

      • Standard DO-311 applies to large rechargeable batteries containing more than 25g of Lithium, ie the 787 batteries. According to the docs linked above they have not yet been defined for small and medium batteries. Leeham mentioned a battery in a post a few days ago that may go onto the Cessna plane. The makers EaglePicher expect to validate it against DO-311 by the end of the year.

        Even if the immediate Boeing “fix” doesn’t bring the 787 battery upto the DO-311 standard, I think there is a good case for the FAA requiring a replacement DO-311 compliant battery in the near term.

  4. Interesting that Boeing would turn to rivals for advice, but then it does make sense. Sharing ideas etc could make the industry safer overall.

    • They don’t turn to rivals for advice. They have a common interest to have an efficient and effective certification process and a common interest to have a workable standard that helps to reduce uncertainty, time and cost of doing business.

      • This “split personality disorder” aspect isn’t evenly distributed between the competitiors.

  5. matjamca :Interesting that Boeing would turn to rivals for advice, but then it does make sense. Sharing ideas etc could make the industry safer overall.

    Airbus, Boeing and Embraer do collaborate on a number of issues related to safety (runway excursions for ex.) and environment (biofuels for ex.).
    Some of these issues are made public, some others not.

  6. Note that some of the tests recommended in the “Comparison Matrix” are quite lengthy, up to a year. For example Shelf Life Test 2.3.4 on pg 7 takes either 12 months at near ambient temp or 90 days at elevated temp. So don’t expect quick return to service unless Boeing skimps again or tests of a better battery began before the fires occurred.

    • It is typical that some longer term tests are not finished before the aircraft goes into service. The test is started at some point before the aircraft goes into service and is continued until the time required to perform the test passes. Since the test has commenced before the aircraft flies, any problems that crop up should be found through the testing and not in the in-service aircraft.
      A classic example is the fatigue rig. They are up and running and have a minumum number of cycles completed before the first aircraft goes into service, and continues running cycles until the required number are performed, which takes a few years to do.

      I don’t think the FAA will allow Boeing to skimp on the required tests and I do believe Boeing knows it is in its own best interest not to do so now.

      • Interesting that this appears to be a bit of a festering problem for Boeing going back to at least 2008.
        About 5 years to handle this and either no usefull output or
        it was regularly pushed back in the problem queue … later, later .

  7. This 2011 document contains a PPT presentation beginning on PDF page 10 that contains a lot of information about testing, the issues, etc., all pre-dating the January JAL fire. PDF page 45 specifically raises the concern about an internal short.

    This presentation (see p41-45 for a summary) highlights how the nail-through-a-cell test is far from an accurate simulation of actual internal shorts. The whole point of this particular research was to create a short inside a “normal” cell without compromising the structure.

    The following presentation covers Cessna’s tests and redesign…

    • Looking again at Cessna’s presentation, it’s interesting that although their new battery casing was demonstrated to pass the explosive test (the video that went round the net a couple of weeks ago) they COULDN’T make the cells cause an explosion, despite trying several methods. Seems to imply the 787 cells are inherently far more dangerous (through larger size and less stable chemistry?)…

      • Working backwards you want to test the containment of a full fire as well as any propagation of an overheating single cell into a full fire. Being difficult to ignite is a desirable feature even if it makes the full fire test more difficult!

        I did read somewhere that battery fires can be random – they ignite or don’t ignite under apparently similar circumstances. Although Boeing seems to have under-engineered its original battery design, they did, I think, run ignition tests on the battery without actually causing a fire. The fact that neither battery caught fire in their respective tests probably doesn’t tell you anything about relatively how flammable each battery is.

        • FF :
          The fact that neither battery caught fire in their respective tests probably doesn’t tell you anything about relatively how flammable each battery is.

          But the Cessna cells *did* go pop very easily – the difference was that they let out a bit of gas and nothing else happened. No fire, no hot liquid, no jets of flame…

  8. Its a whole new ball game when you consider that some of these internal shorts cannot be detected, nor can they be protected against. Boeing is in a box.

  9. FF :
    Even if the immediate Boeing “fix” doesn’t bring the 787 battery upto the DO-311 standard, I think there is a good case for the FAA requiring a replacement DO-311 compliant battery in the near term.

    I don’t know about all the legal ramifications, but in my view the FAA at least has a moral obligation to require the new battery system to be tested against the DO-311 standard.

    • Although Boeing claims some of the tests agreed with the FAA come from DO-311, it doesn’t look the battery will be fully compliant. It is likely that the battery would have to go through a bigger redesign to achieve that compliance. I think (perhaps you agree?) the FAA should insist on compliance – if not now, then soon.

  10. If the FAA insists on compliance now it will prevent a quick return to service. But on the other hand it might also prevent further problems in the future. Which one is best, a prolong grounding that in the end will offer a permanent solution, or a quick return followed by potentially more problems in the future?

    It is better to keep 50 Dreamliners grounded for a longer period than having to ground a fleet of 800 aircraft later on.

    • With “punitive” wriiten so large in the US legal system I miss a bit of “punitive” in how the FAA handles this. IMHO every move goes towards letting Boeing of the hook as easy and as early as possible. No incentives for the future.

      • The beauty of the FAA system, and the way aviation safety is handled in America, as opposed to Europe, is that it is non-punitive.

        Sanctions and punitive actions would actually lower the level of safety, as everyone would be operating in secrecy instead of sharing the information.

      • Going by the Koito seats EASA is stricter.

        But what caught my eyes is the US internal disparity.
        Lenience when profits are endangered.
        Ineffective vindictiveness elsewhere.

  11. SomeoneInToulouse :
    Seems to imply the 787 cells are inherently far more dangerous (through larger size and less stable chemistry?)…

    AINonline:

    – The EaglePicher battery chemistry is lithium-iron phosphate… Lithium-iron phosphate, he said, “is a little more thermally stable” than lithium-ion cobalt technology, which is used in the Boeing 787 battery and Tesla electric automobiles.

    NH: If Boeing wants to stick with Lithium-ion it should use Lithium-Phosphate instead of Lithium-Cobalt.

    SomeoneInToulouse :
    Looking again at Cessna’s presentation, it’s interesting that although their new battery casing was demonstrated to pass the explosive test (the video that went round the net a couple of weeks ago) they COULDN’T make the cells cause an explosion, despite trying several methods.

    AINonline:

    – The Cessna engineers tested the battery to RTCA DO-311 explosion-containment performance standards, and they said that the hardest part was getting anything to ignite. Overcharging one cell did not cause explosion or combustion. By modifying the DO-311 procedure, the engineers were able to generate an explosion, but this included “introducing varying amounts of synthesized vaporized electrolyte gas into the battery to find a flammable fluid-to-air ratio” and installing a fan inside the battery case to mix air with the vaporized electrolyte. They concluded, “The only realistic, but highly improbable, scenario is for a rich concentration of vaporized electrolyte gas to leak out through the battery case seals during in-flight pressure altitude changes until the flammable fluid-to-air ratio for ignition existed. Even with this scenario, the gas would need to be evenly mixed inside the case and be ignited by a source, such as an arc from a loose bus bar, before an explosion [could] occur. This modified procedure was performed and the battery case successfully contained the explosion. No positive feedback thermal runaway, leading to a chain reaction of adjacent cells or sustained asymptotic rise in battery temperature, resulted after the explosion, mitigating the need for vent ports.”

    NH: The question is will the 787 Lithium-Cobalt battery perform the same way under the same testing conditions.

    AINonline:

    – With the lithium-ion battery, engine starts were cooler than with the lead-acid battery, he noted. However, the lead-acid battery’s recovery time for the second start is near zero, he wrote, while “the lithium-ion took up to a minute-plus before the second start could commence.”

    NH: This characteristic was decisive in the selection of Lithium-ion for the 787.

    AINonline:

    – EaglePicher’s battery has passed initial DO-311 tests and will be subjected to further testing with validation by an FAA designated engineering representative before certification.

    NH: We should expect the same for the Dreamliner new battery system.

    http://www.ainonline.com/aviation-news/aviation-international-news/2013-03-01/lithium-batteries-bizjets-remain-scarce-are-coming

    “NH” stands for Normand Hamel.

  12. Single most effective measure will be the reduction of final charge levels and other tweaking of the charger software.
    ( If you reduce capacity of a cell via undercharge damage any computed as correct for the capacity charge will result in an effective overcharge )

    will they reach 1/10e6h failure rate with these measures?

  13. Pingback: More Boeing Q&A on the 787 battery issue | Leeham News and Comment

  14. Pingback: Analyzing the two Boeing 787 press conferences–and new polls | Leeham News and Comment

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