One outsider - As Rainboe says it is not the fact that I can't do a single engine go around flap 15/ 200' (read the second half of post 9). Nor the fact that I can't do a single engine G/A from 50' / flap 40 which was described as "well flown" when I actually knew that was the procedure I should be implementing.
The issue was which procedure do you implement at 50' rad alt -the threshold for (potentially) three different decisions.
(1) If visual contact is made then the decision on an engine failure after 50' rad alt is to land. I suspect this is because a go around from flap 40' at Vref 40 is recognised as being a more risky manoeuvre than landing with the slight yaw/roll associated with a rundown. As I said this was not an option open to me as there was no visual contact...it is mentioned for completeness.
(2) Before 50' rad alt the decision could be to implement the engine failure on approach procedure (non normal procedure 7). You say "of course not" to implementing this procedure at 50'. Fair enough and that is the concencus....you clearly know much more about this than I do so let me ask you WHEN would you implement NNP7? At 51' rad alt? at 100' rad alt...when do you consider that you have a fair chance of achieving Vref 40 plus 20?
(3) At 50' rad alt it seems my instructor was correct to insist on a go around . You must accept however the drag / speed / height margins at 50' Vref 40 with flap 40 selected are not as favourable as with 200' baro /flap 15 / Vref 15.
Air Rabbit / Double Boegy - Having seen the posts here I have accepted my response was not the right one ...but I never take the word of one trainer (however well qualified) on such a safety critical issue. I like to get things verified and find PPRUNE a great way of tapping into an excellent body of knowledge.