Originally Posted by
tdracer
The one big area of concern with composite structure is that it basically does not plastically deform. Over the years, several aircraft have been able to land safely after exceeding structural limits because the metal structure bent but didn't break.
However, the metal in the Merlin helicopter frame shatters like glass it turns out.
The one that beat itself to death at Culdrose from the hover is well worth a look at. It's failure mode looks closer to glass than anything else...