Chuck Ellsworth
I take interest in a couple of points in your post;
Quote: "There is only one reason that I will full feather an engine in flight and that is if the thing has failed mechanically."
If this is the case (and you are instructing in ME aircraft) I feel your students are missing an extremely important part of their transition training. To experience something for the first time and actually do the actions for the first time when you have the stress of a real engine failure/fire/problem can and will only add more stress to the situation;..... crap my engines on fire.....if I pull this lever will the aircraft continue flying.....my instructor said it would......I still have 30 miles to the nearest airport......
And there is the "here is proof" element during training. Using only zero thrust may not convince some students that the aircraft can continue flight, very successfully in some cases, with one engine actually shut down. This could lead to premature decisions being made in the real scenario due to the doubt in performance/handling.
Quote: "Didn't someone arrive somewhere in England recently with one shut down because it wouldn't unfeather after a practice shut down in fligh?"
I would suggest (and I know for fact absolutely nothing of the incident you speak of) that the shutdown may not have been conducted from 3000 AGL (As Angel's One Fife mentioned) and/or the aircraft was in a poor mechanical state and/or the aircraft was not fitted with unfeathering accumulators - all being, in my opinion, requirements for a twin used regularly for shutdowns.
Interested on your thoughts of why not to include it in the training.
AML