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Paul12

Why does G/S not turn to green

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I attempted an autoland at Geneva airport,rwy 05 and noticed that the GlideSlope indication showed white

but did not turn to Green.

The frequency was correct since the localizer turned to LOC in green.

And weirder landing at the same airport and rwy with the B-737 works fine.

 

Any ideas what I could do/try ?

 

Hubert Werni

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Any ideas what I could do/try ?

 

You need to capture it from below (unless you change the setting in the menus). Make sure you're not trying to LNAV VNAV onto it while in a descent. While it's possible, doing so requires that you know the aircraft very well, and given the question here, that isn't quite the case. You should be leveled off (below the GS) while you intercept the LOC, and then the GS.

 

Either way, if GS isn't turning green, it's all in your technique and planning. Capture from below. Let the magic work.

 

The only possible other issue would be a navdata difference, or a lack of a GS in the sim (my home airport of JYO didn't have an ILS back when FSX was created, so it's still a LOC only approach in the sim unless you have add-on scenery).

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You need to capture it from below (unless you change the setting in the menus). Make sure you're not trying to LNAV VNAV onto it while in a descent. While it's possible, doing so requires that you know the aircraft very well, and given the question here, that isn't quite the case. You should be leveled off (below the GS) while you intercept the LOC, and then the GS.

 

Either way, if GS isn't turning green, it's all in your technique and planning. Capture from below. Let the magic work.

 

The only possible other issue would be a navdata difference, or a lack of a GS in the sim (my home airport of JYO didn't have an ILS back when FSX was created, so it's still a LOC only approach in the sim unless you have add-on scenery).

Thank you,I will try your suggestions.What I find weird as well is the fact that using rwy 23 works .

I am about to learn the 777 and followed the procedure explained in their tutorial.

I noticed that my speed was about 20 knots faster then what is should have been according to the

CDU.Could that cause a problem ? Mind you I can try it out myself.

Thanks again,I will be in touch.

Hubert Werni

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I am about to learn the 777 and followed the procedure explained in their tutorial.

If you have not flown Tutorial 1, you need to do so. Just following the procedures explained in the tutorial and trying to adopt them for a different flight is not going to get it.

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I noticed that my speed was about 20 knots faster then what is should have been according to the
CDU.Could that cause a problem ?

 

Nope. The published glide slope intercept for LSGG ILS5 is about 14 nm at 6000. No need to be higher.

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You need to capture it from below (unless you change the setting in the menus). Make sure you're not trying to LNAV VNAV onto it while in a descent. While it's possible, doing so requires that you know the aircraft very well, and given the question here, that isn't quite the case. You should be leveled off (below the GS) while you intercept the LOC, and then the GS.

 

Either way, if GS isn't turning green, it's all in your technique and planning. Capture from below. Let the magic work.

 

The only possible other issue would be a navdata difference, or a lack of a GS in the sim (my home airport of JYO didn't have an ILS back when FSX was created, so it's still a LOC only approach in the sim unless you have add-on scenery).

33wnns9.jpg

I would appreciate if you could explain what you mean by "capture it below" as I don't

understand.

Attached is a screen shot of the ILS05,Geneva.

I use an autoland,Autopilot connected and when asked "reset MCP altititude" I switch

to 6000 feet ( for Belka )

Shorty before reaching Belka I switch LOC on,then when at 6000 feet I switch the APP

on.The G/S shows white but never turns to green.

Again thanks.

HubertWerni

 

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I would appreciate if you could explain what you mean by "capture it below" as I don't
understand.

 

Capture the GS from below. Do not attempt to capture the GS from above.

 

In other words, the GS cue must show that you are "low" or "on glide slope."

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Forget the FMA for a moment and think about the PFD display. The GS is depicted as a white diamond which turns to magenta when it is captured. If the white diamond is above the horizontal flight director bar you are below the GS. The white diamond will start to move down toward the horizontal bar as you approach the intercept altitude. At the intercept altitude, the white diamond becomes magenta and you have captured the GS from below. I believe the GS will turn green on the FMA at that time. If you are above the GS the white diamond will appear below the horizontal bar and the further you fly toward the runway the lower and further way from the intercept altitude the diamond will get. You don't want to try and capture the GS from above because you will need to go V/S mode and increase it to 2000 to 2500 ft. per minute. Then you are going to be too fast to land and you don't want to be descending rapidly  that close to the ground.

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Forget the FMA for a moment and think about the PFD display. The GS is depicted as a white diamond which turns to magenta when it is captured. If the white diamond is above the horizontal flight director bar you are below the GS. The white diamond will start to move down toward the horizontal bar as you approach the intercept altitude. At the intercept altitude, the white diamond becomes magenta and you have captured the GS from below. I believe the GS will turn green on the FMA at that time. If you are above the GS the white diamond will appear below the horizontal bar and the further you fly toward the runway the lower and further way from the intercept altitude the diamond will get. You don't want to try and capture the GS from above because you will need to go V/S mode and increase it to 2000 to 2500 ft. per minute. Then you are going to be too fast to land and you don't want to be descending rapidly  that close to the ground.

I ran again but cannot see a white diamond turning to Magenta when captured. ( On the PFD that is )

Therefore I wonder if something is wrong in my settings.

What puzzles me the most,landing on rwy 23 works.( same airport,LSGG )

Any more suggestions ? Thank you

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What puzzles me the most,landing on rwy 23 works.( same airport,LSGG )

 

Then I'm guessing you're running into one of two things:

  1. Scenery error where your sim's scenery doesn't have a glide slope (or ILS  at all) for the aircraft to track; or
  2. An issue in your technique

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Then I'm guessing you're running into one of two things:

  1. Scenery error where your sim's scenery doesn't have a glide slope (or ILS  at all) for the aircraft to track; or
  2. An issue in your technique

 

Thanks,I believe it is a scenery error since I use the same technique for other ILS and they work

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Everything between the current AIRAC and default FSX Rwy 05 is in agreement. Maybe you are using an add-on airport. Do you have the NGX and if you do have you ever done a LAND3 on 05 at LSGG?

Thanks,I believe it is a scenery error since I use the same technique for other ILS and they work

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Everything between the current AIRAC and default FSX Rwy 05 is in agreement. Maybe you are using an add-on airport. Do you have the NGX and if you do have you ever done a LAND3 on 05 at LSGG?

Yes,I use an add-on airport ( from FSdreamteam ) and yes,I  did the same route using my B-737.And no problem there.Weird.

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I use an autoland,Autopilot connected and when asked "reset MCP altititude" I switch

to 6000 feet ( for Belka )

Shorty before reaching Belka I switch LOC on,then when at 6000 feet I switch the APP

on.The G/S shows white but never turns to green.

If you remain at 6000 ft., which according to the quote you do, you will never capture the GS since the intercept altitude is 3230 ft. The white diamond is probably buried at the bottom of the PFD. Roll the altitude in altitude window down to 3200 prior to reaching BELKA. The T7 will stay at 6000 until it is time to descend. Try that and see if it works.

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I believe it is a scenery error since I use the same technique for other ILS and they work.

So, what was the out come?

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