As one contributor commented at the time, and on listening to the first video posted, there is, now we know more, remarkably little prop noise. A few questions
Is there any kind of protection on the ATR to prevent what is quite a simply made error - even an audible cancellable warning.
This was commanded feathering so no protection against feathering both sides
- sorry just found this - but isn't this a case of if it can happen it will so should there be. Even on a little RV-7 I fly in there is a "flaps flaps" audible warning when they move
Had the error been detected quickly would this have been recoverable. Presume so.
Tragic out come from moving the wrong lever.