I have just spent a facinating 10 minutes watching the seemingly impossible bendings and flexing of the rotor blade with some German guy speaking, I can only say I am amazed at the amount of flexing and reverse bending of the leading edge of that blade, my background is in the steel industry, but the materials used in the construction of the blade in question( was it from 1958) are outperforming even the steel produced today(I mean steel, not special steel).
Would it be possible for some of you more engineered based Ppruners to explain the make up of modern blades, and also do modern Blades still perform in the way that the example in the video does?
Peter R-B