Why so many sceneries for MSFS have misplaced ILS o GS?

[Eclex 102]

The frequencies are not in the airport data made by the  devs. I actually did chat with the Axonos dev and he only said that no one else was complaining.. it is still on ver 1.0.0 i think. Yes, only third party devs create missing ILS airports.

 

Edited January 10, 2023 by Eclex

[vonmar 123]

I did a slow approach (auto pilot off) to KLAX’s ILS24R (MSFS) and seen a dip in the Glide Slope as reported.

Does anyone know where the Glide Slope equipment is located for MSFS KLAX 24R and 24L?


Has anyone tried KLAX ILS 06L?
I did a short video for MSFS default KLAX ILS06L just to see [autopilot off] if there were any sudden drastic G/S deviations.

https://youtu.be/NOQUQZYIoLA

 

 

 

[crimplene 634]

3 hours ago, vonmar said:

 

I did a slow approach (auto pilot off) to KLAX’s ILS24R (MSFS) and seen a dip in the Glide Slope as reported.

Does anyone know where the Glide Slope equipment is located for MSFS KLAX 24R and 24L?


Has anyone tried KLAX ILS 06L?
I did a short video for MSFS default KLAX ILS06L just to see [autopilot off] if there were any sudden drastic G/S deviations.

https://youtu.be/NOQUQZYIoLA

 

 

 

This is super strange. I did 24R again with the FBW A320. No dip in GS at all. Super steady diamond and 700 fpm descent. Over the threshold the diamond moved up as expected.

For ILS 06L I am not sure I understand why you went below the ILS GS. I tried it with The A320 again, but didn't lock GS. Instead I locked the LOC and set the AP to FPA -3.0 degrees. Here I had sort of an epiphany. 🙂 The glideslope was exactly 3 degrees until about 300 feet AGL. Then the diamond dipped a bit but came back up at maybe 200 feet and stayed centered until it moved up at less than 100 feet AGL. So yes, there seems to be a small anomaly.

Edited January 10, 2023 by crimplene

[vonmar 123]

1 hour ago, crimplene said:

This is super strange. I did 24R again with the FBW A320. No dip in GS at all. Super steady diamond and 700 fpm descent. Over the threshold the diamond moved up as expected.

For ILS 06L I am not sure I understand why you went below the ILS GS. I tried it with The A320 again, but didn't lock GS. Instead I locked the LOC and set the AP to FPA -3.0 degrees. Here I had sort of an epiphany. 🙂 The glideslope was exactly 3 degrees until about 300 feet AGL. Then the diamond dipped a bit but came back up at maybe 200 feet and stayed centered until it moved up at less than 100 feet AGL. So yes, there seems to be a small anomaly.

Turn the autopilot Off and do a video of your visual approach / glide slope to KLAX ILS 06L

Edited January 10, 2023 by vonmar

[crimplene 634]

37 minutes ago, vonmar said:

Turn the autopilot Off and do a video of your visual approach / glide slope to KLAX ILS 06L

Hm, the ILS GS to 06L has exactly 3 degrees with a slight down bump near the threshhold. Does your video show otherwise? Flying this without AP would not help. The AP clearly proved that the GS is exactly 3 degrees. And of course the GS hat the correct altitudes at the waypoints per Jeppesen charts.

For recording a video I would have to activate either Windows Games stuff (forgot the name) or the nvidia software. And I would have to change to 1080p. Too much of a hassle, tbh. If need be, I might do that, of course.

But first, would you mind to explain what is wrong with the ILS GS in your opinion and why you approached below it. I simply don't understand the problem (apart from the bump, which is clearly there).

For clarification: I still use the Supreme (or whatever) version of MSFS. I have no clue if we are approaching the exact same KLAX airport.

Edited January 10, 2023 by crimplene

[crimplene 634]

I did a video. 🙂

KLAX 06L. What you can see:

- me configuring the ILS in the MCDU
- me flying the approach
- me over-correcting a lot
- a 3 degree glideslope
- a little dent in the glideslope near the 300 feet AGL mark (slightly exaggerated by me overcorrecting upwards)
- a good landing on the left side on the center line.

Did that help somehow?

 

[vonmar 123]

Hi Crimplene,

For my No Autopilot visual approach video I wanted to approach below the G/S to better see:

1. If there were any sudden / drastic G/S deviations.

2. The approximate altitude when crossing the threshold.

3. At which point did I intercept the G/S.

I had previously asked : Does anyone know where the Glide Slope equipment is located for MSFS KLAX 24R and 24L?

Nice video.
I noticed your GS dip happened when crossing from ocean shoreline to scenery airport elevation.



Note : 
The plate for KLAX ILS06L says the G/S is 77 feet above the threshold (119 feet) so 196 feet MSL crossing the threshold. 

I used a default MSFS (1.29.30 Premium Deluxe) aircraft for the test to rule out any potential problems with freeware/payware aircraft.

[crimplene 634]

Ok, thx for explaining!

Just a very lose idea: could somehow the terrain elevation of the airport scenery influence the ILS glideslope in MSFS? Not that I ever experienced this, but still. This would mean that those GS dips should/could/might happen at the border of the airport scenery if there is any problem or specific circumstances regarding the scenery. Ok sound like a wild theory. And I am not sure I want to spend time trying to prove or falsify it. 🙂

[JRBarrett 3,070]

51 minutes ago, vonmar said:

I had previously asked : Does anyone know where the Glide Slope equipment is located for MSFS KLAX 24R and 24L?

Looking at an aerial photo of KLAX, the runway 24L & 24R g/s antennas are located adjacent to the white touchdown markers of the runways. That is pretty much standard placement for a glideslope antenna.  

[vonmar 123]

27 minutes ago, crimplene said:

Ok, thx for explaining!

Just a very lose idea: could somehow the terrain elevation of the airport scenery influence the ILS glideslope in MSFS? Not that I ever experienced this, but still. This would mean that those GS dips should/could/might happen at the border of the airport scenery if there is any problem or specific circumstances regarding the scenery. Ok sound like a wild theory. And I am not sure I want to spend time trying to prove or falsify it. 🙂

Hi crimplene,

I figured you would get that idea when I mentioned:

I noticed your GS dip happened when crossing from ocean shoreline to scenery airport elevation.

Many flight sim airports are on an elevated area.

 

 

 

 

[vonmar 123]

27 minutes ago, JRBarrett said:

Looking at an aerial photo of KLAX, the runway 24L & 24R g/s antennas are located adjacent to the white touchdown markers of the runways. That is pretty much standard placement for a glideslope antenna.  

Hi Jim,

I need to now the G/S antenna location (KLAX, the runway 24L & 24R) in MSFS.

 

[JRBarrett 3,070]

1 hour ago, vonmar said:

Hi Jim,

I need to now the G/S antenna location (KLAX, the runway 24L & 24R) in MSFS.

 

There is no easy way to tell (in MSFS) without decompiling the BGL files that contain the navaid data. There may (or may not) be a visual antenna object in the scenery that represents the glideslope antenna, but such an object would not necessarily have any relation  to where the glideslope actually originates in the navaid files.

I use Navigraph nav data for MSFS, and have been since it was first made available over two years ago, because I trust it to be accurate.

That may not be the case with the default NavBlue data. It is better than it used to be, but I have seen some pretty egregious errors in the default MSFS nav data in the past.

Based on the way the aircraft and glideslope indicator behaves (using Navigraph) on both the ILS24R and 24L at KLAX, I have every reason to believe that the glideslope transmitters are correctly placed for these two runways.

[vonmar 123]

Hi Jim,

Thanks for the follow up information.

I searched and found ADE2020 (for MSFS) but I do not know how to use it to like I would with ADE for P3D or FSX.

 

[crimplene 634]

Would Navigraph data influence the precision of the ILS in MSFS? I assumed that the localizer and GS antennae are a fixed part of the scenery. I use Navigraph, too. Didn't mention that before, sorry.

[JRBarrett 3,070]

2 hours ago, crimplene said:

Would Navigraph data influence the precision of the ILS in MSFS? I assumed that the localizer and GS antennae are a fixed part of the scenery. I use Navigraph, too. Didn't mention that before, sorry.

The antenna imagery (if present) is just a scenery object, no different than a tree or building. The scenery designer can “drop” one anyplace they wish. It may correspond to the actual antenna location, or it may not.

Navaids such as VORs, NDBs, and ILS localizers and glideslopes are contained in BGL files that begin with the letters “NAX”. They are in the scenery hierarchy for a given airport, but separate from the main airport scenery. They control where navaids are placed - latitude, longitude, elevation, range, frequency, heading and beam width (in the case of localizers), magnetic north alignment (in the case of VORs) etc. 

These BGL files can be overridden by by those installed by Navigraph, (placed in the Community folder, and given a higher priority than the default). 

I am in the process of cross checking the default nav data for the KLAX ILS 24R and 24L glideslopes with the Navigraph versions, and comparing them both to the official FAA navaid data records for those two glideslopes. I’ll post my findings.

Edited January 11, 2023 by JRBarrett