Originally Posted by
Pugilistic Animus
I remember reading about lightning protection on the 787...IIRC there is a copper mesh embedded in carbon fiber
Disclaimer - I'm not a lightning/EMI expert, but I did have to deal with it for my engine systems - I know just enough to be dangerous
Yes, there is a copper mesh imbedded in the carbon fiber on the 787. While carbon has reasonable electrical conductivity, it's still considerably worse than aluminum (order of magnitude). That higher resistance means that the electrical current/voltages induced by a lightning strike are much higher than for aluminum structure. The copper mesh dramatically improves the conductivity of the carbon, but it's still a bit worse than aluminum. As a result, the lightning transient requirements for the 787 systems are somewhat higher than for aircraft with aluminum primary structure (I don't recall specifics, but IIRC the voltage requirements were about twice as high for carbon fiber aircraft).
Clear? Pop quiz in the morning
