This was touched on in JB and I'm not implying that Boeing have not solved the problem.
If, for example, a 787 has a GPU reverse into it and bounce off without doing much apparent damage, how do you know?
Plainly it would dent or crease a metal aircraft but that CFRP is tough stuff and certainly wont dent. It might leave no mark at all but still be weakened by the impact- or not!. How do you tell?
Second issue. If the a/c is punctured, how on earth do you repair it? Bearing in mind that the repair will need to be good for the remaining life of the a/c.
Looking forward to finding out!
