ILS Heading

Hello guys,
Noticed on some of my airports modified with ADEX that when landing the airplane does not land in the center line of the runway and some times completely away from it, and the wind is not the factor.
For instance on one of my airports SPSO the feather of the ILS, perfectly centered with the central line of its runway reads: ILS frecuency 109.55 & Heading 219.44. Now my procedures to fix the ILS frecuency and heading is to look for them by opening the MAP in my P3Dv4.5 and when this is done place them to my SAITEK panel to fly with them. Now the odd thing that I found is that the heading shown in the MAP is not the same and reads 218.
Why is this diference, and can this be the reason for the plane not landing correctly
Appreciate your thoughts and comments


Resource contributor
In some cases, a course that is projected by localizer is at an angle to the runway this is usually due to obstructions near the airport (Ye Old Crane and TV mast). It is then referred to as a localizer type directional aid (LDA). The localizer system is placed about 1,000 feet from the far end of the approached runway. Usable volume extends out to about 18 NM for a path up to 10° either side of runway centerline. At an angle of 35° either side of runway centerline, the useful volume extends up to 10 NM. Horizontal accuracy increases as distance between the aircraft and localizer decreases. Localizer approach specific weather minimums are found on approach plates.
ok understand the issues behind a non precision approach.
But is this the reason of the heading reading difference: heading 218 at the MAP and 219.42 at ADEX airport and will there be any correction during the approach if I were to choose the Adex airport heading of 219.42 instead of 218

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Resource contributor
IT might be a differential set on the ILS in AP development either in the sim environment or Actual has changed. Id set the ILS to the MAP every-time especially following some quick checks across various charts available sites not just Jeppson which are often OOD.

You said that your ILS FRQ is 109.55. The FSX default is not showing an frq. The Jeppson is 109.7


Resource contributor
As stated above I'm not quite sure what you are seeing. In my FSX SPSO has no ILS on runway 22 (in fact no ILS at all). When I sit on runway 22 the heading is 220. It's possible you are having a true vs magnetic heading problem, since the magnetic deviation here is 1 degree, and thus that might explain the 1 degree difference you see?
Well let me tell you that SPSO has in fact no ILS and I created one using ADEX adds, which reads a frecuency of 109.55 and a heading of 219.42 that changes to a heading of 218 when I look for SPSO in P3D MAP having created the flight plan with the Flight Planner. The aircraft follows the ILS, follows the glidepath and Does not land in the center line of runway 22 and what I am trying to find out is the reason for this heading difference, being that P3D is “working” with the SPSO created with ADEX and if there be any difference if I use the heading shown in ADEX.
Don’t know if I am getting you all confused, because I am sure are, and thanks for your time and comments

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Hi, hope I understood well what you are experiencing. Are you sure that both ILS and runway have exactly the same heading and that the localizer antenna is positioned exactly on the extended center line of the runway? Because of the lenght of the runway (about 3 km), a little difference in these two parameters, can lead to an erroneous position at the touch down.


Resource contributor
Mameni, lets step back a little please.

What charts did you use to get the correct ILS frequency for SPSO. (JEPPSON of 2016 is here - )

As Tom states in FSX there is no ILS at all for SPSO. Therefore we appreciate you added one but where has the 109.55 come from please.

In addition when looking at the aerial of FSX and google earth RWay threshold 04 in fsx is about .1NM(184 metres) from the sea when in reality its about 520metres from the threshold to the shoreline as the crow flies.

As Mr Croc suggests look for the localizer anenna used for RWay 22 Because of the shoreline in the sims (any and all versions) it might be that its offset due to limited space (the sea) as some are in the real world because of space issues, obstacles in line with the ILS feather. therefore in this case - this airport may have, based on your sim an LDA which is an ILS that is not aligned with a runway, although it may or may not have a glideslope.

There are a few reasons why. A major one being terrain/obstructions on or near the extended centerline of the runway. Another one is the location of the transmitter .
Hello guys,
MrCrok, the ILS localizer positioned on the runway reads: Ident IABC, Runway 22, Freq. 109.55 MHz, Heading 219.4200, and the runway 04/22 reads: Heading 039.4200, and yes the localizer antenna(feather) is positioned exactly on the center line of the runway.
gfx, I did not use charts to get the ILS frecuency and 109.55 was selected from a drop list of ADEX ADD ILS. Now there are many frecuencies on that list and chosed the selected one.


Resource contributor
When selecting ILS Frq its always wise to go through as many charts for that airport as possible as you may just have any old frequency but its wise to select that most in keeping with the one charts have.

It might be wise to break this one down

Consider removing the frequency and changing it to the LOC DME in the Jepp chart. Compile and test - if you come in exactly the same they its not the frq issue. Then remove the local from the end of the runway 4, save and compile and check to see it another feather or anything else appears. reinstall the LOC at the exact runway end set the fre and distance again and try then try back coursing the approae from 04 and see how you go. Lets see what we get
OK guys, made some of the suggested corrections, such as perfectly centering the ILS with the center runway line, removing the localizer from the end of runway 4, and used a small aircraft such as a Beech craft in order to checkout the touchdown, and I think that this time I had a centered touch down as per the photos attached.
Thanks for your advice