Thank you for your replies.
As far as situational awareness is concerned, it was planned to be a use of "autopilot and flight director" IFR training flight, which was made in excellent weather conditions on a straight airway. The area, whilst being sparsely populated, does have a number of villages and small towns, which should have been clearly visible.
Both propellers - according to preliminary report type MC Cauley 3AF32C522/82 NJA-6 - appear feathered. That the cockpit controls do not confirm this is interesting.
Does anyone have any opinion as to why the left engine has no cowlings at all and the right one does?
We value your continued input.