In the real world, APPR is pressed when ATC says “Cleared for the approach”. APPR is only going to intercept and follow the GS/GP to the ground, which is intercepted at or near the final approach fix. In MSFS, APPR would need to be pressed prior to that point. However, if doing an LPV approach, APPR and VNAV both have to be pressed but that is not modeled in the sim yet and that procedure can vary between avionics manufacturers.
1 Like