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dwf2008

What controls glideslope

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When making an ILS approach to DTW Detroit in FSX, ATC directs us to an altitude of 2600 for runway 4L. I find that this is too high to intercept the glideslope and the plane just flies over the runway. However if I approach at 2400 I do hit the glideslope and the plane decends as it should. What file needs to be tweaked to get this to sync correctly?

 

And how do you do it?

Thanks

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Which ATC? The default FSX ATC? If that is case, it is well-known that FSX's approach data for airports is so well-out-of-date. Why don't you look at up-to-date Approach Plates which will give you the latest ILS capture data?

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Yes, its the default ATC. Where would I find newer approach plates and how would I install them?

Thanks for your reply.

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There are quite a few freeware sites that have Approach Plates.I have no idea where you are flying to-----more info, more help?

 

Use your friend Google to search, then you either print it of or put it in a place you can refer to. I use AivlaSoft's EFB, a payware product which does everything such as route planning and Approach Plates.

 

Your choice.

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http://flightaware.com/resources/airport/DTW/IAP/ILS+Z+RWY+04L+%28CAT+II+-+III%29/pdf

 

To Intercept the ILS at 2600ft,  one would have to be at least 7.7 nm out from the runway.  

 

Approach fix "PAYED"  is 7.7nm, at 2600ft.

 

If you are closer than 7.7nm  @ 2600ft,  you will be BELOW the glideslope, and your AP  will not automatically capture  the glideslope.

 

So the question becomes,  how far out are you when the FSX ATC  instructs you to "Maintain 2600ft till you are established".

 

There is only a problem if this instruction is issued by FSX ATC  when you are closer than 7.7 nm

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vc10man - Notice the first post said I was flying to DTW, Detroit Metro.

 

BeachPilot - If I am below the glideslope I should intercept it  as I approach the runway. Thus as I said, it works OK if I maintain a higher altitude. My question is not how to fly a glideslope, but what config files define it. Is it defined in the AFCAD file? And if so how can I tweak it?

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- Notice the first post said I was flying to DTW, Detroit Metro.

Ah, yes, my bad! You did indeed. Need to take a trip to SpecSavers!

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BeachPilot - If I am below the glideslope I should intercept it as I approach the runway. Thus as I said, it works OK if I maintain a higher altitude. My question is not how to fly a glideslope, but what config files define it. Is it defined in the AFCAD file? And if so how can I tweak it?

 

I think he meant to say the glideslope is below you and thus you won't capture it.  It sounds like ATC is vectoring you to intercept the localizer too close in for the altitude they're holding you at.  The problem is most likely not the localizer and glideslope configuration in the AFCAD, but the imprecise nature of FSX' built in ATC, and there's really not much you can do about that.  The issue you're having can be best visualized when you look at the chart.  Here's one of the two versions of the 4L ILS: http://155.178.201.160/d-tpp/1501/00119IZL4L.PDF.

 

Scott

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Hi,

 

The announced approach height is controlled by the Approach.  AFAIK, the only way to alter this is to use ADE (Airport Design Editor).  Quit FSX first before editing this.

 

1.  Load the airport into ADEX (if a default airport File/Open Stock Airport, if addon File/Open Airport from BGL).  

2.  Click the Approach Mode button in the upper right and choose Lists/Approaches.

3.  If nothing appears, close this and click the Airport Mode button in the upper right.  Click Tools/Load Stock Data.  Check Approaches, and Navaids and Waypoints, OK.  When done, go back to Approach Mode, and use Lists/Approaches. 

4.  Your Rwy 4L ILS approach should be listed; click it and then the Edit button. 

5.  Look near the bottom of the right side.  You will see Appr Alt Feet  and 2600. 

6.  Change this to 2400. 

7.  Save the AD4 file somewhere safe (File/Save Airport, you will open this file to make further edits, do NOT edit the stock or addon airport BGL file again!). 

8.  Use File/Compile Airport to create the new airport BGL file.  If you started with a default airport, this BGL file can go into your Addon Scenery/scenery folder.  Make sure you don't have any other KDTW airport files in this folder.  If an addon airport, save it in the airport scenery's scenery folder.  Give it a new name, do NOT overwrite the original file.  Then move the original file out of this "scenery" folder (I move it to the parent folder, the one with the airport's name).  That way it stays safe as a backup.

9.  Restart FS.

 

Try it out, and hopefully ATC will announce 2400 ft this time.

 

Hope this helps,

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