However, I do believe that an RNAV equipped aircraft is able to intercept and successfully complete the IAL when under its' own navigation when intercepting at the FAF. So if on a vector - quite rightly we put the aircraft on the LOC prior to the FAF assigned an altitude that allows GS capture from below and meets the altitude requirements of the sector being flown. If the aircraft is on its own nav - I clear it to the FAF assign it the lowest I can (RLSALT or approach commencement altitude) to meet the foregoing and the wizz bang gear in the aircraft does the rest.