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answered KTIW ILS final approach course alignment


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Having trouble at KTIW in MSFS. The ILS 17 final approach course does not seem to be aligned with the runway. 

 

Using the skyvector FAC of 167 I'm coming in offset to the west. I assume it's operator error but it happens in multiple airplanes at KTIW and not right across the street at KSEA.

05186IL17.PDF

 

 

 

KTIW ILS FAC.JPG

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10 hours ago, spanx said:

I assume it's operator error

 

Definitely not operator error but something strange is going on here!

I see the same problem with both our scenery and the default scenery.

Looking at the charts they seem to contain inconsistent information.

 

The ILS in both our scenery and the default is set to 167 degrees magnetic - which is correct according to the charts.

ILS.thumb.jpg.3a61523bc9f5cc1c44519be7dba38170.jpg

 

The runway heading, however, is around 171 degrees magnetic - in both the scenery and according to the charts.

Chart.thumb.jpg.567d86a4b29ddaef3f81e5456926572d.jpg

 

The magvar of 15.6 on the chart would give a true heading of 187 for the runway.

 

Various sites I've visited give the runway heading as 187 true, 167 magnetic (which suggests a magvar of 20 degrees, incorrect according to the chart).

For example https://www.airnav.com/airport/KTIW

 

The only way I can see of making the ILS work as it should would be to set the localizer course to the runway heading (187 true) - even if this means the 'tuned' course seems incorrect when compared to the chart.

 

All the best,

 

John

 

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6 hours ago, spanx said:

Thanks for the quick response guys. Appreciate it.

 

No problem. I'm in touch with my son, who's a pilot in the USA. He has looked at the charts he has and is also scratching his head.

 

He reckons the localizer on the field will be calibrated correctly but the approach charts (and therefore the MSFS info) may well be wrong as to the bearing.

 

 Will let you know if the FAA admit to an error :)

 

All the best,

 

John

 

 

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1 hour ago, John Burgess said:

Will let you know if the FAA admit to an error :)

 

Thanks for the follow up. Just for fun, I fired up an ancient copy of P3D and the 167 final lined up perfectly. I know that's not a real data point but it might indicate this is more of an MSFS thing than an FAA thing. I guess I could call KTIW and ask if people are constantly crashing on the west side of the field when it's IMC. ;)

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2 minutes ago, spanx said:

I know that's not a real data point but it might indicate this is more of an MSFS thing than an FAA thing

 

We'll see. I didn't fly it in P3D but looked at the databases and, as you say, they seem to be okay.

 

The charts, however, are nothing to do with MSFS or P3D - as far as I know these are the ones pilots actually use - and they don't seem consistent with each other.

 

Hopefully we've at least provided the info needed to get things working correctly in MSFS!

 

All the best,

 

John

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This is a bit of a puzzlement. The Jepp plate also shows 167° for the final approach course, but then 167° magnetic for the runway. There's very seldom disagreement between the FAA's digital flight info (here) and Jepp, but this seems to be one. It's been years since I've flown the real KTIW ILS, but I recall it being perfectly aligned with the runway. Unfortunately, the C182 I have access to is down for annual, but when that's done, I'll have to go fly this and see what it looks like IRL. It's an easy flight from my home base of Bremerton National/KPWT.

Edited by Gulfstreamtwo
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Just back from a sim flight and the KTIW localizer looked pretty good, especially with real weather. I use the stock G1000 172, WT G1000NXi and current Navigraph database, so that may be part of the answer. And of course the Orbx KTIW add-on. As you can see from the screenshot, that right 24K crosswind puts the airport well off to the left (yellow arrow) and me a bit off to the left as well, but correcting to the right more and localizer centered, I was looking right down the centerline. If you know what to look for, the Garmin/WT flight path vector is parked right over the approach end of the runway (left side of the airspeed tape) on the display (the FPV is a great tool for managing approaches as it tells you exactly where the present energy state will put you). The localizer was also aligned with the runway centerline on short final.

 

2071480758_KTIWILS.thumb.jpg.cbecdd7edb591c4c1d2eda06c06c39a1.jpg

Edited by Gulfstreamtwo
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30 minutes ago, Gulfstreamtwo said:

Navigraph navdata and Orbx KTIW.

Thanks for taking the time to look at this. I took out the 172 from your example and still see the same problem. I don't know what "Navigraph navdata" is (total noob). Is that what comes in MSFS?

KTIW CESSNA ILS 2.JPG

Edited by spanx
clarity
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Navigraph is a subscription-based add-on that replaces the sim nav database with its own. It also includes a chart app and access to high performance flight planning. As a noob (and welcome to the hobby!), I suggest Navigraph a little way down the road for you unless you want their IFR charts for the world.

 

It now seems entirely likely this is actually a bug in the in-sim NavBlue nav data. I'm done flying for the day, but if no one else reports the same thing you see with stock nav data, I'll disable my Navigraph and see how things look tomorrow night. My bet is I'll see what you see.

Edited by Gulfstreamtwo
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9 hours ago, Gulfstreamtwo said:

Unfortunately, the C182 I have access to is down for annual, but when that's done, I'll have to go fly this and see what it looks like IRL. It's an easy flight from my home base of Bremerton National/KPWT.

 

That would be interesting (I feel rather envious!).

 

I have old jeppesen charts from 1995 (the old simcharts) which have the runway heading and approach course as 167 with a magvar of 20 degrees. As far as I can discover the magvar is now about 15.4 so I'm guessing that currently the headings should be around 171 or 172 but for some reasons the charts haven't been updated and the MSFS navdata is incorrect for the ILS. I don't have Navigraph installed and see what Spanx does.

 

The only chart which seems to be giving the currently correct value would therefore be the government airport chart.

 

Presumably IRL the localizer beam is on the correct heading (187 true) so you would just keep the needle centred and would hardly notice any discrepancy - even with the HSI set to 167.

 

All the best,

 

John

 

 

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I just flew this with Navigraph turned off and was able to duplicate the OPs observed issue. My thought is that the Orbx KTIW is fine and that the error is caused by incorrect navdata in the sim. This is with the released January 31 version as well as the prior one. The issue is easy to create as well as fix by turning Navigraph on (correct alignment) and off (incorrect alignment). Here's what I see with Orbx KTIW and default sim navdata:

Untitled.thumb.jpg.a96613150ad1814c78f7c627e9510f31.jpg

Oddly, while I centered the heading bug just before takeoff and its centered here, you can see the runway is now misaligned.

 

With Navigraph active, it looks like my previous screenshot:

Untitled.thumb.jpg.47a90f6cbd2bad38c0325f6c161679b3.thumb.jpg.1912ab4b5e69625caa0c424c3b5d89a0.jpg

Edited by Gulfstreamtwo
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1 hour ago, Gulfstreamtwo said:

I just flew this with Navigraph turned off and was able to duplicate the OPs observed issue.

 

That first photo looks strangely familiar. :) Thanks for taking the time help validate this issue.

 

 

Edited by spanx
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On 1/31/2022 at 1:47 AM, John Burgess said:

 

That would be interesting (I feel rather envious!).

 

It was a nice surprise to get access to the plane and get back flying again. You can see the tail number, N2700P, just peeking out from under the glare shield in the above two pix. It's what can happen when you do something helpful for someone without expecting anything in return and they respond way beyond your imagination.

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2 hours ago, Gulfstreamtwo said:

It was a nice surprise to get access to the plane and get back flying again.

 

Appreciate the help though can't see the pics.

 

I've reported our findings on the beta forums so, hopefully, at some point things will be fixed.

 

Navigraph clearly fixes things - the only reason I don't have it is because it could make me miss things when testing!

 

All the best,

 

John

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Thanks, John. This is proof of why that's a necessary approach for testing. Having to always have a clean sim with no add-ons for beta testing (besides the test add-on of course) is why I stopped. It also makes me appreciate even more those that add to the community by diligent testing instead of getting into a beta solely to have the latest software. Proper beta testing is hard and mostly boring work, doing the same profile over and over to look for bugs or validate bug fixes worked while not introducing new ones.

 

I see there was a small update this morning to the sim to incorporate the AIRAC that took effect last Thursday. I won't be able to check it until later today, but I'll report back when I do (unless someone beats me to it). 

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