Originally Posted by
EasternATC
The current SV limits are standards that were written in a different era of technology. Everyday, thousands of airplanes at hundreds of airports are joining localizers outside of 18 miles, and they're all tracking quite reliably.
No....much of the technology is still the same and even with the newer loc antennas or GS antenna - the SVs remain the same. Yes....100s of aircraft may be intercepting locs outside 18nm. MANY locs have ESVs outside of 18nm. You, as a pilot or controller, might very well not know if a loc, (or any other ground based NAVAID) has an ESV. One clue on the chart would be any point located outside of SSVs with DME provided from the facility - as was the case with the example of LAX Rwy 25s from earlier in the thread.
Sluggo -
The localizer course may be flown outside of the 18 nm flight-check distance if the instrument procedure depicts a greater distance or radar service is provided. If the controller clears you to intercept a localizer course, regardless of the distance from the antenna, radar service is being provided and you are expected to intercept the localizer.
In the first bolded case - there would be an ESV if the procedure depicts a fix outside of the SV. Until I ask my co-workers for further clarification, I'll state again that in a case such as EasternATC or the OP may be describing, **technically** the aircraft would be under radar control outside of the SV while "intercepting and tracking the localizer", because **technically**, without an ESV, the localizer signal does not exist outside of the SV and signal strength and quality of the signal in space can not be guaranteed to meets minimum tolerences.