Hello sorry for my English, I have a problem with the pmdg 737/800 ngx I make a simple flight only with vectors of the simulator atc prepar 3d v4.2. in the proximacion to any intercept track the locator without problems the problem is that I never intercept the glide path and it only happens to me with this plane my speed is 180 and flap 15 sorry for my ignorance but I am new this passionate world a greeting and thx in advance

Edited March 28, 20188 yr by Carlos Jimenez Garcia

Carlos, the simulator's (both FSX/P3D) have a very simplistic and unrealistic ATC feature.  It is not worthy of use unless you are simply using the simulator as an expensive game.

Be sure you have charts for the procedures you want to fly in the simulator.  You should have a chart for the ILS you want to use and it will tell you what the Initial Approach Fix (IAF) and Final Approach Fix (FAF) for the approach.  You need to have an awareness of where you are in the simulation world with respect to the key fixes on the chart.  The normal ILS is executed by intercepting the LOC, which you say you can do, and there being below the GS one either holds altitude or maintains a descent of less than 800 fpm to intercept the GS.  Couple of things you might not know yet:  Most ILS GS are 3 deg, equivalent to about 318 ft/nm, rule of thumb is about 1000 ft per 3 nm and at normal approach speeds the rate of descent is around 800 fpm (depends on groundspeed).   This means if you are 8 nm from touchdown, your GS will be about 2500 ft above touchdown elevation. Hope this helps.

By the way, if you have not yet flow the Tutorials for the NGX I highly recommend you do so.