That's the origin of carbon fibre.
When I was on 32's Whirlwinds in the 70s we had a chap who had been there on Sycamores. He had a lump missing from one of his calves where he was hit by a lump of rotor blade during a Sycamore ground resonance event.
Re: droop stops, on the Whirlwind, for a stuck droop stop we would climb up the side, open the service platform and crouching down below the whirling machinery, knock the stop into position with a two foot length of broom handle. Happy days.