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Flight Director Providing Wrong Information on ILS Approach


Frafty

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I was on final into RWY 14R at Omaha following the Flight Director until I realized that it wasn't matching up with the ILS...like at all, as indicated by the photo below. 

 

1. The screens are small, and the color of the GS is very hard to see when the screen is that small and the color of the GS is that bright to where it doesn't contrast enough.

2. Knowing the above, I was scanning between outside and at the flight director (which should be following the ILS laterally and vertically since it's active and APPR mode is armed), until I realized that the flight director was completely off as I started getting lower altitude call outs (300ft is when I noticed it) and given the distance I was from the threshold.

The red circle shows where the glideslope is on the PFD, and you can see the horizontal bar on the FD indicating where I should be pitching is...below the horizon, which is clearly not correct.

 

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It’s the right frequency because it’s auto tuned. And the course shouldn’t matter as it doesn’t dictate what the FD does. The FD is controlled by the computers to tell you vertical and horizontal guidance. The course is more of a point of reference. 
 

 

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5 hours ago, Frafty said:

It’s the right frequency because it’s auto tuned. And the course shouldn’t matter as it doesn’t dictate what the FD does. The FD is controlled by the computers to tell you vertical and horizontal guidance. The course is more of a point of reference. 
 

 

Ugh no...  The Course "Radial" does matter...  If you are flying an ILS you have to have the course dialed in correctly...  Now does that change how it should compute the GS?? probably not.. But it will dictate where the Autopilot that generates the Flight Director thinks its supposed to place you....  This is also why there are "offset" LOCs....  You flying down a path between mountains on a 151 course and then you reach MDA and if you see the runway... it's at 160...  Well if you had put 160 in the course not 151 your FD would run you into the mountain on your LEFT side ....

 

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4 hours ago, LesOReilly said:

Ugh no...  The Course "Radial" does matter...  If you are flying an ILS you have to have the course dialed in correctly...  Now does that change how it should compute the GS?? probably not.. But it will dictate where the Autopilot that generates the Flight Director thinks its supposed to place you....  This is also why there are "offset" LOCs....  You flying down a path between mountains on a 151 course and then you reach MDA and if you see the runway... it's at 160...  Well if you had put 160 in the course not 151 your FD would run you into the mountain on your LEFT side ....

 

The course setting is only for the pilot’s visual orientation. Unlike a VOR, a localizer does not contain any embedded bearing information - the deflection/centering of the needle is based solely  on the aircraft’s physical position in space in relation to the center of the localizer beam.

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38 minutes ago, Frafty said:

Any idea if this will be looked into?

The ILS (glideslope capture in particular) is THE focus of development right at the moment. It is an extremely complex issue, but good progress is being made.

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14 minutes ago, JRBarrett said:

The ILS (glideslope capture in particular) is THE focus of development right at the moment. It is an extremely complex issue, but good progress is being made.

 

Very happy to hear!

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  • Deputy Sheriffs
On 4/22/2021 at 9:16 AM, JRBarrett said:

The ILS (glideslope capture in particular) is THE focus of development right at the moment. It is an extremely complex issue, but good progress is being made.

This is the best answer currently, as well as to the issue raised by the OP. When it's solved, you'll see plenty of notice, so no need to keep this open and no need also to ask about progress. This kind of issue is not subject to linear resolution, and besides, some sim or world update may undo progress.

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