According to information received by Helsingin Sanomat, the blades overheated some time ago, as the pilot was taking off. The turbine exhaust gases heated up the blades to such an extent that the rotor-blades began to shake on ascent.
Helsinginsanomat news
Interesting! The blades had been replaced so were not an factor in the accident but I didnīt know this could happen. Is it because the engines are started with rotors still on the S76?