Learn what ILS Y and Z suffixes mean in MSFS 2024, why the procedures differ, which one to load and how to handle a missing FMS variant.
In MSFS 2024, ILS Y and ILS Z are separate published procedures for the same runway, not different ILS accuracy levels. The suffix distinguishes variants with different transitions, routing, equipment requirements, minima or missed approaches. Choose the procedure named in your clearance or the one matching your flight plan and aircraft capability.
What do the Y and Z suffixes actually identify?
The suffixes give unique names to ILS procedures that would otherwise have identical titles. For example, an airport might publish both ILS Y RWY 27 and ILS Z RWY 27.
In many procedure-naming systems, letters are assigned backwards from Z when multiple approaches of the same type serve one runway. This is an administrative naming convention, not a ranking: Z does not mean newer, easier, more accurate or more suitable than Y.
| Procedure element | What may differ between Y and Z |
|---|---|
| Initial routing | Initial approach fixes, transitions and feeder routes |
| Equipment | Published RNAV, DME or other aircraft requirements |
| Restrictions | Altitude, speed and course constraints |
| Minima | Decision altitude, visibility or aircraft-category minima |
| Missed approach | Climb instructions, routing and holding fix |
| Final ILS guidance | Usually the same runway localiser and glideslope, but the published frequency and course should still be verified |
The letter belongs to the procedure name. It is unrelated to the L, C or R identifying the left, centre or right runway.
Which ILS variant should I load in MSFS 2024?
Load the exact Y or Z procedure specified by ATC; without a clearance, choose the one whose routing, requirements and transition suit your flight.
- Read the complete approach name. If the clearance specifies ILS Z for a runway, do not load ILS Y merely because both finish on that runway.
- Match the transition. Select an initial approach fix that connects sensibly with your arrival or last en-route waypoint. A vectors transition expects heading guidance rather than an automatic route to every fix.
- Check the procedure notes. Confirm that the aircraft and its avionics meet any listed navigation requirements.
- Inspect the loaded legs. Look for discontinuities, implausible turns, duplicate fixes and unexpected course reversals before activating the approach.
- Verify the final approach data. Check the localiser frequency, inbound course, minima and missed-approach instructions rather than assuming the Y and Z entries are interchangeable.
Once the correct variant is loaded, localiser and glideslope capture work normally. Our MSFS 2024 localiser and glideslope walkthrough covers navigation-source selection, approach arming and common capture failures.
Why can ILS Y and Z use the same frequency?
The suffix identifies the complete procedure, while the ILS transmitter provides guidance for the final segment. Two variants can follow different routes to the final approach fix, merge onto the same localiser and then use different missed-approach instructions.
The cockpit indications therefore need not change once the aircraft is established. For the underlying relationship between the localiser, glideslope and published approach, see our practical explanation of ILS guidance and procedure structure.
Does ILS Z mean CAT III or autoland?
No: Y and Z do not indicate the ILS category or autoland capability. CAT I, CAT II and CAT III approval depends on the published procedure, ground installation, aircraft equipment, operating conditions and applicable minima.
An aircraft may be able to follow either variant automatically, but that does not make either procedure an autoland approach. The suffix alone says nothing about landing capability.
Why is an ILS Y or Z approach missing from the FMS?
A missing variant usually means the simulator planner and the aircraft are using different navigation data, the procedure has been renamed, or the avionics do not expose every transition.
- Look for abbreviated names such as
I27-Z,ILS27Zor a suffix shown in a separate field. - Confirm that the selected runway number matches the airport scenery; runway renumbering can leave older scenery and newer navigation data out of step.
- Compare the procedure sequence in the EFB or flight planner with the aircraft's FMS. Stock and third-party avionics may not always present identical entries.
- Check whether the missing item is the entire approach or only a transition. The main procedure may still be available through another initial fix or vectors entry.
Do not substitute Y for Z based solely on the landing runway. If only one variant is available, compare its fixes, requirements, minima and missed approach before using it; the shared localiser does not make the complete procedures equivalent.