quote: How is it that an intersection often doesn't get a traffic signal until there's an accident there? Because there are millions of intersections and it would be financially impossible to put signal at every one of them.
quote: By this analogy, the original 787 battery design, which had:3. Inadequate fire and smoke containment and venting
quote: As for the battery itself, two kinds of insulation were added: an electrical insulator and a thermal insulator, which will wrap around/below each battery cell to keep them away from each other and the battery case.
quote: To be fair, if you look at pics of the battery which caught fire, the battery is destroyed but the external case appears pristine. So apparently it had adequate fire and smoke containment (not so sure about the venting). In that respect there was no danger to the plane.
quote: The problem was the batteries weren't supposed to catch fire in the first place, but they had two incidents within the first few months of service. Which led to a reassessment of the fire risk, forcing a redesign which assumed a higher frequency of fire. So now they're adding things like isolating different cells from each other so a fire doesn't spread as easily between cells.