Don't even slightly agree. I don't think the instructor should set zero thrust until the student is ready to 'feather' the failed engine. If things get too out of shape, push the throttle forward and you have normal 2 engine climb to complete a circuit and try again
The purpose of automatic feathering in some aircraft was to instantly reduce the drag caused by a windmilling propeller. This safety feature is not fitted to light twin engine training types. The usual method of teaching the actions for engine failure after take off includes having the student verbally state each action he intends to take culminating in the simulation of manual feathering by the instructor setting zero thrust. Verbalising each action takes time whereas an experienced pilot needs only to glance at each item to ensure full power on the live engine, that the mixture is rich or the appropriate setting for a high density altitude airport.
Prompt reduction of drag caused by a windmilling propeller is of paramount importance. Every second delay in feathering the dead engine propeller results in loss of airspeed. Indeed, in some propeller systems it may not be possible for the propeller to feather if the windmilling RPM gets below 800 RPM. So the instructor must ensure the student is aware that the step by step method usually taught on initial twin engine endorsements has its limitations in real life.
A few years ago, there was a fatal accident with a Duchess at Camden when the instructor (30,000 hours) decided to cut the right hand engine mixture control during a touch and go and shortly after the student (a 16,000 hour current B767 captain) had selected gear up. The drag caused by the windmilling propeller was so great that airspeed fell quickly well below best single engine rate of climb before the instructor could re-start the engine and re-introduce power. The aircraft clipped tree tops which reduced speed further and the aircraft stalled and belly landed on rising terrain. Both pilots were unhurt as the aircraft slid to a stop. Unfortunately, a fuel tank ruptured after the aircraft hit an iron girder as it stopped and the aircraft caught fire. The instructor later died of his burns while the student was seriously burned.
Years before a Cessna 404 (?) had an engine failure shortly after lift off from Essendon runway 35. The aircraft was unable to gain altitude and in attempting to avoid power lines flicked inverted below Vmca. All aboard were killed. The propeller of the failed engine was windmilling because for some reason the pilot (10,000 hours plus) failed to feather the propeller.
Another accident occurred at Essendon when a Dove departing from runway 17 suffered an engine failure seconds after lift off. The pilot (13,000 hours) selected gear and flap up as per his training but never got around to feathering the engine due to his pre-occupation with selection of the gear and flap handles. The aircraft crashed into houses wings level and everyone survived with only minor injuries.
Each of the pilots involved in these three accidents were highly experienced. In each accident the drag of the windmilling propeller proved to be the critical factor in loss of climb performance.
No doubt, students undergoing initial twin engine endorsements have never heard of these three accidents and probably their instructors have not, either. The point being that instructors are not infallible and that allowing the airspeed to rapidly decrease because of a windmilling propeller to below safe single engine climb speed while the student talks his way through the engine failure drills is not a good instructional technique. Call it practicing bleeding if you like.
The instructor must be prepared to set zero thrust quickly to prevent a potentially dangerous airspeed loss even though the student is still working his way through whatever emergency drills he has been taught. Some students have difficulty coordinating their words with their actions which is the same problem that many trainee instructors have when undergoing an instructor course. Stumbling over words while trying to control the aircraft from yawing caused by a windmilling propeller, is difficult enough for an experienced pilot let alone a student on his first twin.
Instructors have a duty of care and that includes the safe operation of the aircraft under their command. Teaching the skills to handle an engine failure shortly after take off, carries with it a higher risk than normal. If setting zero thrust before the student has got around to it is considered poor teaching technique by some Ppruners reading this thread, then it is suggested they may learn from obtaining the ATSB reports on the three asymmetric accidents described here.