At about 1:22 on the #18 video, you can see one of the rail rotor blades suddenly change angle in the rotational plane. Instead of being 180° opposite the other blade, it moves round to about 150/210° from the other blade.
So a link of some sort must have let go and this would have set up a strong catastrophic out of balance vibration, which eventually caused both blades to separate, owing to fatigue failure followed by the hub.
Very soon after this it sounds that engine power was reduced ?, so it seems the pilot was doing the right thing to recover.
Very scary to watch - especially how quickly it happened, and I hope the human injuries are not too bad.
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Last edited by Uplinker; 12th October 2025 at 14:11.