Originally Posted by
Dan1113
Interesting. Regarding number three, do you reckon then that we would have seen a much bigger disaster in SFO had the plane been a 787 instead of a 777?
I heard that the 787 isn't as good at handling lightning strikes due to its materials - is that accurate?
And regarding number two, is that something that would happen right away, or is this going to be a case like those crashes where something that was done ages ago (ie the wire being screwed too tightly) is attributed to crashes years down the line?
Regarding 2 - it's related to heat cycles. So, yeah, it may happen over time. Most electricians don't want to touch aluminum wires in a "critical" business installation, but in 787 it was an integral design choice to reduce weight and improve fuel efficiency. In the most extreme case, the lugs are copper and the wire aluminum. They have different rates of thermal expansion, so every time it heat cycles, it causes more stress. This failure can happen even when all components are aluminum, but differing metals increases the risk.
Regarding 3 - When carbon fiber fails, it tends to lose all strength instantly -- think of it like an egg shell -- can be quite strong (try breaking one by squeezing the top and bottom in your hand!), but as soon as a crack forms, it has nearly no strength at all. As far as how that would relate to the Asiana 777 crash @ SFO, it's tough to say, but the bigger risk is that one tiny imperfection while midair, and suddenly you effectively have zero structural integrity. I think @ SFO, most passengers were already off the plane by the time the fire became a serious problem, simply because the fire was clearly so hot that it melted aluminum (very hot!), and no human could survive that environment, and the injury count was too low for a fire like that to be in proximity to humans without injury.
On the flip side, something that will deform will absorb shock, so it's possible that there would be less injuries in a 787 crash.
I think the 787 is probably a wonderful plane as long as nothing is wrong, and probably on par with the 777 in the event of a major emergency (perhaps even safer due to the deformation absorbing shock), but the risk of a major emergency is probably much higher due to so many unreliable components.
I'd personally like to fly a 787 just once. Statistically a low chance that it will be "that" flight, but I think in the long run, they will be deemed unsafe, and scrapped.