Thanks to all you performance experts for your contributions.
Glueball: in basic terms, my question is why does one operator specify a turn and another not in the case of an engine failure from the same runway in an identical aircraft?
john_tullamarine: as per the above, you are correct in (a), I am not comparing apples and oranges, just similar apples from two different suppliers! However, your answers do throw light on the query.
mutt and m&v: thanks for your contributions.
As I readily admit, performance is not my top subject but I am a little the wiser now!