Approach clearance to intercept INTERMEDIATE FIX
 

Hi there~

Let me ask you something.

FAA 7110.65 4-8-1 4.Established on a heading or course that will intercept the intermediate segment at the intermediate fix, when an initial approach fix is published, provided the following conditions are met;

(a) The instrument approach procedure is a GPS or RNAV approach.


Why is only available RNAV approach?
Why is not possible on ILS approach?

Could you explain me the reason in detail?

All aircraft inbounding our airport have advanced RNAV equipment and our Air traffic controllers issue approach clearance using intermediate fix on ILS approach procedure. Is this wrong?