The question is basically this (and I apologise for if I did not make it clear).
Once airborne the turn is initiated at say 2.0 dme based on the ILS DME (of the landing runway). Assuming the DME is exactly between the landing thresholds (to read 0 when landing) where EXACTLY does the turn begin at?
I know it is intiated when the pilot's DME reads 2.0 but what does that mean in practise? Is is 2.0 DME from the landing threshold of the runway in use or is it 2.0 DME from the landing threshold of the runway not-in-use? If a constant electronic "adjustment" of the DME is used (say 0.7 in this example) and all readings are reduced by this same 0.7 DME then the turn ACTUALLY begins at 2.0 from the landing threshold of the runway not-in-use.
And, if we have a long runway and a small aircraft - you will actually fly towards the dme transmitter!
HP