The crash of the PH-DDA back in the 90s was due to a stuck valve in the feathering pump IIRC. This one at least got close to the feathered position.
edit:
https://aviation-safety.net/database...?id=19960925-0
paragraph 2.1.3 explains what happened there.
Last edited by Jhieminga; 10th Dec 2021 at 15:52.