Remember back in 2013 when Boeing’s 787 Dreamliner was grounded because of concerns about the batteries catching fire and causing serious issues? Boeing eventually came up with a solution that involved a reinforced housing for the main Lithium-Ion battery. It is a containment system that includes a vent to allow fluids escaping an overheating battery to leave the plane. And, as far as we know, the usage of that system is rather limited. But it also turns out that we might not know all the incidents because the NTSB doesn’t necessarily track them.
Last month the pilots of a United Airlines 787-8 en route from Washington-Dulles to Paris-CDG reported a main battery overheat warning shortly before landing. Ship N26909 landed safely at CDG, with evidence that the liquid venting system worked. The return flight to San Francisco was canceled. Indeed, the plane spent nearly 4.5 days on the ground in Paris as a result of the incident. When the plane finally returned to the skies it was ferried to Denver via Dulles. Just over two days later it ferried to San Francisco before retuning to normal operations in the company’s route network.
In many ways this is a normal sequence of events. A maintenance incident occurs. The plane is pulled from service. It is inspected and/or repaired as needed. It returns to service. The abnormal part comes from the way the NTSB appears to be treating it. Aviation Herald reports that it is a “non-reportable event” so no investigation will occur. Boeing did provide confirmation of the incident as a courtesy to the organization.
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To be clear, I’m not worried about the design or reliability of the containment system. I believe the Boeing engineers that it will properly manage a battery overheat and prevent potential damage from spreading. I’d place the batteries in personal electronics that end up in the cargo hold (even though they’re not supposed to be there) as a much greater risk. At least we no longer have US authorities demanding that those electronics be placed in the cargo hold. We even have movement from US carriers (and IATA almost certain to follow suit shortly) prohibiting even more batteries from finding their way into checked bags.
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But when we have an aircraft component that is known to be troublesome, so much so that it led to a fleet being grounded, it makes sense to me that maybe keeping track of how often that component is still failing, even when a containment system exists. If nothing else, wouldn’t it be useful to track how well the containment functions to “prove” that it is a sufficient approach to the solution in practice?? Seems the NTSB is not keen on requiring such tracking. And, while it is great that Boeing is volunteering the information it really isn’t quite the same thing.
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I saw that on avhearld and was wondering why it was getting almost swept under the rug
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.
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.
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.
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
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.”
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