Hopefully someone can help me.I am trying to fly a star with my pic 737.the last part of my star requires me to fly a specific heading for a specific distance before turning to intercept the localiser.the intersection where I make my turn has no frequency etc so how can I measure the distance I have travelled using the dme equipment so I know when to make my turn to intercept?I tried tuning to the run way ils but this figure increases as I start to head away from the airport.Thanks rich

Air traffic control usually tell you when to turn, plus when flying an instrument approach, the HSI will show you your positioning to the localiser. And you could tune into a VOR you've passed if that's a part of the STAR, if you wish to monitor DME.

What Ant said: see if there is another navaid from which you can measure distance - often on approach plates you will find distances measured as X from Y navaid, and A from B navaid. It often had nothing to do with the ILS/VOR at the airport.If you can post the chart, we can say more.