Following on from the previous discussion I have the following question.
Consider an airfield that has 2 ILSs (same freq) and a common DME transmitter sited half way between the runways. The DME system, I understand, has an electronic "adjustment" so that the DME for each ILS reads zero at the threshold. So far so good.
However, if the SID for a runway in use, uses the ILS DME to initiate a turn where is the DME measured from? I assume the electronic "adjustment" is effectively a negative correction (say 0.7 mile) so that at touchdown the DME reads 0.
But after lift off, the aircraft flies towards the DME transmitter and then flies passed it before initiating the turn so if the turn is at say 2.0 DME - is the effective turn taken at 2.0 + 0.7 dme passed the DME station? (which is actually 3.4 DME from the start of the landing threshold)
HP