Hello I had a question about different types of approaches, I was wondering what the difference was between when it says “ILS” “LOC” and just straight up nothing on the RWYS on the airport information. If landing at a runway where you’re able to activate the LOC does that count as an ILS? And if flying into an airport with neither ILS or LOC what types of approaches can I do? Thanks!
5 Likes
Hey @Ben_G!
Here is a quick breakdown of the differences:
- ILS (Instrument Landing System): Provides both lateral (left/right) and vertical (glideslope) guidance. It lines you up with the runway and guides your final approach.
- LOC (Localizer): Provides only lateral guidance. To answer your second question: flying a LOC does not count as an ILS because it lacks the vertical glideslope. You will be lined up horizontally, but you have to manage your altitude manually. Although most runways with a LOC almost always have an ILS.
- Nothing: This means there are no instrument approach aids for that specific runway.
If you’re flying into an airport without ILS or LOC, you can opt for a Visual Approach, using your eyes and runway lights like the PAPI to guide you, or, when available, a GPS (RNAV) Approach, aligning with your GPS flight plan and using VNAV to step down your altitudes.
If a runway is equipped with both LOC and ILS, and you select LOC, you will also automatically be established on the ILS.
7 Likes
Alright makes sense so what would LOC fall under? What type of approach is it? GPS? @Jaxx
1 Like
Approaches are named after the navigation equipment used during the final approach segment. Examples include ILS, LOC, GPS, RNP, VOR, DME, TACAN, NDB. On an ILS, you get glideslope information and course information from a localizer. On a LOC, you only get course information, again from a localizer.
As far as whether flying a LOC “counts” as an ILS is context specific. Are you talking about being cleared for an ILS approach whether you can fly the localizer only minima?
When flying into another airport without a localizer you can either use another NAVAID’s approach or fly a visual approach.
Edit 1: I reviewed the IF ATC communication manual. It appears that if you are cleared for the ILS approach then you are cleared for the LOC approach as well. There’s no option for the controller to clear you for the only localizer approach. They are lumped together.
3 Likes
Most approaches are categorised as 3-D or 2-D approaches (I think they are also called precision and Non-precision approaches). A 3-D approach (Precision approach) would be an ILS/DME approach or a LNAV/VNAV approach for example. A 2-D approach (Non-Precision app) would be a LOC/DME approach, VOR/DME approach, NDB/DME approach, LNAV approach (also known as GPS or RNAV or RNP approaches).
A Localiser/DME approach is not considered a GPS approach, however it can be flown using GPS for distance instead of DME. A GPS approach would use Satellite based waypoints for tracking, where as like previously stated, a Localiser is a ground based navaid that emits a signal in 150HZ and 90Hz for the aircraft to recieve for tracking.
3 Likes
Yes so if you were to be cleared for the ILS your cleared for a LOC approach thank you.
1 Like
Alright thanks Dhannis
So basically my question is with all of those approaches you mentioned when your in contact with ATC you either pick Visual, ILS or GPS so which would those approaches fall under is what I mean? @Ksisky
1 Like
LOC falls under ILS because there is no option for ATC to clear you for a LOC only approach.
2 Likes
I can’t understand why during an ILS approach I always end up off centre, normally I have to drop out of AP and self correct…any ideas anyone?
Welcome to the community @Geordie90210!
If you mean the aircraft isn’t perfectly centered on the ILS, it could be because some approach procedures don’t line the aircraft up exactly with the localizer, so you will have to do the heading manually and align it yourself before turning on APPR to avoid the wobbly corrections.
If you mean it won’t capture the glideslope, it might be your speed or altitude. Try to keep an eye on the green diamond on the PFD (HUD) that has to be in the middle and make sure you’re stable when intercepting.
1 Like
Your autopilot may also be set to track whatever waypoints you’ve input to the GPS, versus tracking the localizer.
1 Like
Thank you, both of those give me something to work with!
alright thanks
This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.