Originally Posted by
blakmax
Most rotor blades are fabricated by adhesively bonding skins onto the spar and a honeycomb core. Adhesive design properties change significantly with temperature, the hotter the adhesive, the lower the strength and stiffness. If they get hot enough, the temperature may pass what is termed the Glass Transition Temperature where they change from a stiff glassy material to a soft, weak rubbery material. My guess is that the adhesive became so weak that the weight of the blades and the ash caused the blade to fail.
So sad.
Blakmax
Then why are the plastics, etc, on the fuselage and transparencies essentially intact and apparently unaffected by the same heat?