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Olbia LIEO ILS 23 glideslope wrong position


jgoggi

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Hi,

The glideslope of ILS 23 (111.30) at Olbia LIEO is badly positioned, because if I follow it I always get 4 red papi's and on final I almost hit the trees. Could you please check and move it to the exact position, so that I have 2 white and 2 reds?

Thank you!

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I just ran a test and the PAPI lights are red all the way when on GS but the ILS GS appears to be set correctly, see screenshot.  It brought me in to the piano keys reasonable accurately, certainly didn't push me into the trees.

 

The problem with the PAPI lights might be because the 05 ILS is 3.5 degrees not 3 degrees so if the developer used the same frequency for both ends, it would explain the discrepancy.  If you use the PAPI lights rather than the ILS GS, it'll put you above the 3 degrees GS and you should be high at the threshold, not low, and with no chance of hitting the trees.

 

Anyway the PAPI lights could be looked at for an update, and for me, the 111.30 frequency brings the Bonanza in at around 3 degrees and it's accurate enough to ensure a safe landing at decision height.

 

LIEO1.thumb.jpg.2fd82e47ad694d6a1128f9d2f8249f97.jpg

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Hi John,

No, the ILS of runway 05 is 109.90, while rwy 23 is 111.30, so it's not the same ILS. Further, with a small plane you are quite separated from trees, but with a big liner you see them dangerously closer.

Therefore the GS is badly positioned and needs to be checked, because if you are on it you have to see 2 reds and 2 whites.

Thank you.

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34 minutes ago, jgoggi said:

Hi John,

No, the ILS of runway 05 is 109.90, while rwy 23 is 111.30, so it's not the same ILS. Further, with a small plane you are quite separated from trees, but with a big liner you see them dangerously closer.

Therefore the GS is badly positioned and needs to be checked, because if you are on it you have to see 2 reds and 2 whites.

Thank you.

 

No not necessarily.  If the glide slope is set correctly, as it appears to be for this runway, then the approach will allow you to land on the numbers by following the glide slope in your instruments.  In this case it appears that the PAPI lights are set to the wrong slope. The fact you are seeing the wrong indication from the PAPI lights does not alter your ability to follow the glide slope to the runway art 3 degrees.

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1 hour ago, jgoggi said:

... because if you are on it you have to see 2 reds and 2 whites.

 

The above is not correct. On short final at many airports there is a discrepancy between PAPI and ILS indications in real world. This is stated in quite a few YouTube tutorials about flying ILS approaches by real world pilots. Then the ILS signal is lower then the PAPI path.

 

On long finals it very often is the other way round, because it is quite a difference in height sitting on a 747 flightdeck or in a Cessna 152.

 

So generally PAPIs are more applicable for smaller GA planes rather than airliners

 

But I cannot specifically comment on LIEO, becauseI don't own this scenery.

Edited by wolfko
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Guys, thanks for your opinion, but I still think that the glideslope is wrong.

I am a flight test engineer and in real life I have always seen the GS not matching the PAPI *only* in very short final, never before. In our case at LIEO you have 4 reds all the time, even from a long distance and you do have the feeling that you are too low...

I have a long experience in P3D with this issue (present in many sceneries), but there it was easy, I loaded the AFCAD file with ADE and moved the GS to the correct position, beside the PAPIs. In MSFS this is not possible.

Further, the ILS of runway 23 is 3.00 degrees, so I don't see why the PAPIs would not have that angle...

 

Edited by jgoggi
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58 minutes ago, jgoggi said:

Guys, thanks for your opinion, but I still think that the glideslope is wrong.

I am a flight test engineer and in real life I have always seen the GS not matching the PAPI *only* in very short final, never before. In our case at LIEO you have 4 reds all the time, even from a long distance and you do have the feeling that you are too low...

I have a long experience in P3D with this issue (present in many sceneries), but there it was easy, I loaded the AFCAD file with ADE and moved the GS to the correct position, beside the PAPIs. In MSFS this is not possible.

Further, the ILS of runway 23 is 3.00 degrees, so I don't see why the PAPIs would not have that angle...

 

 

Yes that's right.  The PAPI angle has been set wrongly.  The glide slope however appears to be correct.

 

I don't know what CAT this ILS is but unless it's CAT III, the decision height is 100' or 200' minimum, the GS is designed to get you to a point where a manual landing is straightforward with sufficient visibility, from where adjustments in height and angle are often necessary to land on the runway.  They are not designed to get you all the way to touchdown.

 

The developer can look at the PAPI lights for a future service pack, in the meantime, flying the glideslope accurately according to your instruments, and not worrying about the PAPI lights for the time being, will bring you to the decision height at 3 degrees from the touchdown point, and from there you can perform a normal stable landing.

 

 

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  • 1 month later...

Update would be nice, as I just encountered this:

355695218_LIEOPAPIvsGS.thumb.jpg.b2e7b395c8f8a69c89264941c6d4499d.jpg

Looks to me like the PAPIs are spot on, leading to a landing in the TDZ (as they should), while the G/S is so far off it doesn't even show anymore.

Edited by TomL
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