Localizer Extended Service Volumes

Does Navigraph data have an effect on the distance a localizer can be received within MSFS?

yes and no - the standard ranges are following:

US and CAN - 18NM
Rest of the world - 25NM

This is what is set currently in data. We don´t have more specific information per ILS, therefore the standard values.


Can those distances be customized with additional data?

Those localizers are woefully short for a vast majority of operations at I’d venture to say all Class B and many Class C airports around the US.


No, not at the moment.

Possible, but thats the default values according the FAA, and we don´t have any other information available. Do you have any example ILS, that I can check it. Thank you!


Every localizer at KORD, and localizers for 31C and 4L at KMDW as well.

I know all the KDEN ones too. KLAX has at least 2 that are flight checked to 85 miles.

I’d venture all the localizers at any Class B airport extend beyond the “defined” course.

The AIM is just a bare minimum. A huge number of localizers have extended volumes. I can provide more details as necessary, but at a bare, bare minimum, the localizers have to cover all the fixes identified on the approach course.

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I assume I found a way to calc this information. Just make a few more checks.
Not sure, if it´s implemented with AIRAC 2112 but I guess with AIRAC 2113 it should be fine.

For testing, do you have a few airports/approaches with such localizer ESVs?

Thank you,

Yes, see above post. I’m out and about for now, but you’ll find them at any of the Class B airports around the US as a start.

Also, the ESV extends beyond the last published fixes on the localizer, but that is a variable requiring reference to specific paperwork not shown on published approach procedures.

Thanks - I mean, what would be helpful are a few examples with the real-world ESVs.

As from your example:

KMDW 31C - HILLS is the IAF, which is approx. 15nm from the localizer - so why should there be an ESV? Same for the 04L … TASUE is the IAF, 5nm from JERNU (IF) and JERNU is approx. 10nm away from the runway - so in total 15nm …

KDEN I07C - SARAH (FACF) is 14.2nm away from IDZG

I mean, these/your examples would be all in the 18nm limit … and what do you mean with beyond the "defined" course


Ah, understood.

Off the top of my head, I know I-LAX (KLAX ILS RWY 25L) is flight checked to 85 NM.

The main reason is that ATC needs more localizer to vector aircraft to for sequencing and spacing during high volume periods or IMC conditions.

I’ll touch on more later.

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Thanks, take your time …

Alright, I have a little time to type here now.

“Beyond the ‘defined’ course”, I meant that many localizers have an expanded/extended service volume beyond the cited AIM Standard Service Volume. A couple subparagraphs below there’s actually an example of the KORD ILS RWY 4R and its expanded volume.

Attached is an example of the Chicago TRACON video map that includes the localizer course depictions for KORD and KMDW, along with some other smaller airports in the airspace. The primary point being that the E/W runway localizers almost all reach out to a 40 mile range on the video map, and ATC uses these distances when necessary.

I looked at the video map for KDEN as well to see ILS RWY 7. It’s depicted out to 22 NM from the arrival end of the runway.

This situation is repeated in many other places in the country.

I’m sure that localizers are like many radios… given line of sight they can be received at absurd distances, but they are only certified for use within a given range. The Standard Service Volume of 18 miles is just the minimum.

Thanks - ok understood but it looks there is no source of this and that makes it nearly impossible to know what loc uses the ESV and which not.

I have also looked in the FAA database, also here no information, so my only reference is the minimum range.


The major problem is that it’s quite immersion-breaking for sim pilots flying in to the largest airports, let alone the effects on virtual ATC and general lack of realism. If someone fly an ILS, and the chart says a localizer signal should be there, but it’s not in the sim, that’s quite less than ideal.

Do you have examples of what the nav data includes for ILS info on a given approach?

If the data identifies conventional fixes located on a localizer course, you can be all but assured that the localizer is flight checked to the distance of the farthest published fix and then some.

Is there a way to private message by chance? I’d like to discuss something more directly.

we have now implemented the localizer ESVs - so, the ranges should be ok according the FAA rules from AIRAC 2112 on.

Here an example KORD:


Well that’s pretty cool, I appreciate the effort.

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