Difference between GPS and ILS approach

[Ianuccelli]

I have always been confused by what the two mean can anyone explain to me what they mean?

[EdCruz]

Hey!

A GPS approach is given when you are approaching a runway with a grey cone. The GPS approach will give you accurate localizer, but not always keep you clear of terrain (inaccurate glideslope). ILS (red cone) will give you accurate localizer and glideslope. And Visual can be used for any runway. It essentially has you establish yourself on the localizer.

For both ILS and GPS approach should clear you approximately 30° off the localizer and you’ll have to intercept yourself.

Note that not all training server controllers know what their doing, so don’t expect complete professionalism from them. Hope this helps!

[Ianuccelli]

Oh ok thank you I have always been confused by it and I have giving an ILS approach into SFO and I thought it was like APPR landing.

[George]

@EdCruz

A GPS approach is given when you are approaching a runway with a grey cone. The GPS approach will give you accurate localizer, but not always keep you clear of terrain (inaccurate glideslope).

I’ll give a slight correction here

“The Global Positioning System (GPS) Approach is a non-precision approach within IF but is not commonly used as functionality is currently limited. The GPS Approach is defined by a series of waypoints and altitude restrictions that the pilot will follow to the runway threshold, free of conventional guidance such as a localizer/glideslope etc”

Quoted from Infinite Flight ATC Manual

In other words, you can also apply GPS Approach to runways equipped with ILS aswell. Basically by flying GPS Approach, you are following the altitudes of VNAV on Infinite Flight (Usually as part of “Approach” or IAP procedures). While in ILS Approach, you are following the glideslope of the runway (It’s only available for runways equipped with ILS). Hopefully it clear some confusion 😃

Also check out @Maxim’s post below 👇

[Maxim]

@EdCruz

For both ILS and GPS approach should clear you approximately 30° off the localizer and you’ll have to intercept yourself.

That’s not true. ILS clearances are 10 to 30 degrees offset from the runway heading, but GPS clearances do not require an intercept (or altitudes or headings for that matter, unless to deconflict with traffic and or terrain). We are told the best place to clear someone for a GPS approach is on their base leg (or any other appropriate position like final if the GPS is a straight-in for example).

I know you’re trying to help and that’s great, but let’s make sure we’re giving folks correct information in the first place to avoid confusion further on.