5 Responses

  1. Sean Roebuck
    Sean Roebuck at |

    I saw that on avhearld and was wondering why it was getting almost swept under the rug

  2. Stephen Trimble
    Stephen Trimble at |

    It’s not an issue. The GS Yuasa battery is not designed to never fail. Like all airplane batteries, it’s designed to fail in a harmless way. So the failure of a single cell that does not propagate to other cells and releases no fumes outside the battery enclosure is not a safety problem. There have been two such incidents since the battery and enclosure redesign in 2013, which was prompted by battery failures that were by no means harmless.

    1. Seth Miller
      Seth Miller at |

      I agree that it is not a safety issue and that some failures are to be expected. I’m just slightly surprised that the feds aren’t tracking the incidents a little more closely.

    2. Stephen Trimble
      Stephen Trimble at |

      For three years after the 787 battery failure, the FAA basically put a blanket hold on all lithium ion batteries used in aircraft electrical systems, even those that were intrinsically far less volatile and far more conservatively installed than the 787 battery design. There’s no reason that lithium ion is any less safe than nickel cadmium, the less energy dense chemistry that lithium ion replaces. When nickel cadmium was introduced in the early 1970s, there was also a battery safety crisis as industry and regulators adjusted to the failure modes of the new technology. My magazine ran a feature in 1972 headlined “The Great Nickel Cadmium Scare”, as planes were falling out of the sky because of short-circuits in their brand new nickel cadmium batteries. Those failures led the FAA to impose battery design and installation rules for nickel cadmium in 1978, which Boeing ignored with the FAA’s blessing 30 years later with the 787 on the grounds that they believed lithium ion was inherently safer. When that assumption proved wildly wrong, the FAA required Boeing to adhere to the same rules made for nickel cadmium. Individual cells in nickel cadmium batteries also sometimes fail, but the FAA isn’t concerned because the 40-year-old rule works really well at preventing those failures from causing greater harm to the aircraft.

  3. Michael
    Michael at |

    Maybe no NTSB incident report, but did you check FAA service difficulty reports? Much lower bar.

    I don’t see any from submitter CALA for a Nov 13 incident on a 787 but it also looks like they submit their SDRs in batches and the latest available is Nov 12 right now.

    Here are all the 787 related SDRs logged from Aug to Dec so far:

    Selected Unique Control # Operator
    Designator Difficulty
    Date N-Number Aircraft Make Aircraft Model JASC
    CALA2017080802554 CALA 8/8/2017 27957 BOEING 7879 3350
    CALA2017082102823 CALA 8/21/2017 38955 BOEING 7879 2560
    CALA2017082102822 CALA 8/21/2017 19951 BOEING 7879 2560
    CALA2017082502868 CALA 8/25/2017 13954 BOEING 7879 2150
    CALA2017082502874 CALA 8/25/2017 27901 BOEING 7878 3350
    CALA2017082802925 CALA 8/28/2017 29961 BOEING 7879 2560
    CALA2017110303907 CALA 11/3/2017 26906 BOEING 7878 3350

    Among those there was a battery incident in August but … “CAPTAINS EMERGENCY FLASHLIGHT INOP REPLACED FLASHLIGHT BATTERY. OPS CK GOOD.”