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TszChun

Rethinking Data Link Function

11 posts in this topic

Hello all,

 

What do you guys think of the principle of data link function in PMDG 777. When I flied FSX, I used to use it with Active Sky in my every flight to get wind data and descent forecast. Here is my understanding of how the function works:

 

I selected departure runway and SID, MANUALLY entered the route WITHOUT selecting STAR.

 

When I clicked WIND DATA REQUEST in RTE DATA page, it seemed that a RTE file was automatically generated in documents/P3D v3 files/ by the 777 which was then read by AS16.

 

After that, AS16 acknowledged my route by reading that RTE file, and created a WX file containing wind data of waypoints in PMDG/WX folder.

 

The FMC loaded that WX file and display wind data in RTE DATA page.

 

I would like to ask you guys two questions:

 

1. Do I still need to manually load the route into AS16 flight plan page? Or it will be automatically loaded into AS16 after I activate the route in FMC?

 

2. How come AS16 knows my attitude to reach waypoints when the RTE file generated does not contain expected FL?

 

3. If I modify the route in cruising stage, let's say adding a STAR at the end of the activated route, will I be able to REQUEST WIND DATA again for the STAR waypoints newly inserted?

 

Anson

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I would like to ask you guys two questions:

You have three questions.

 

1) No. The route is loaded automatically when you request the winds.

 

2) AS16 does not know your altitude at any waypoint. The altitude is just a guess by AS16.

 

3) Yes. Just request the winds after you have entered the STAR. However, a major part of the STAR will be traversed during descent. So the descent forecast is what applies to the STAR. Maybe the first two or three waypoints might be at your cruise altitude in which case a wind request would handle those waypoints.

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The Introduction document has a fairly good explanation of all this. You'd save time by referring to it.

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You have three questions.

 

1) No. The route is loaded automatically when you request the winds.

 

2) AS16 does not know your altitude at any waypoint. The altitude is just a guess by AS16.

 

3) Yes. Just request the winds after you have entered the STAR. However, a major part of the STAR will be traversed during descent. So the descent forecast is what applies to the STAR. Maybe the first two or three waypoints might be at your cruise altitude in which case a wind request would handle those waypoints.

 

That's exactly what I think! But last time I flied the 777, the STAR waypoints could not get wind data when I requested, while the others are OK...

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the STAR waypoints could not get wind data when I requested, while the others are OK...

 

The LEGS waypoints after TOD do not receive wind info, that is what the descent forecast page is used for.

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That's exactly what I think! But last time I flied the 777, the STAR waypoints could not get wind data when I requested, while the others are OK...

I did not reply to your question because it was already answered in post #2, answer #3 and Dan Downs has reiterated it again. If you have a particular route and STAR list it here. I need your cruise altitude, any step climbs involved, your cost index, date and time (UTC)of departure for the flight.
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You have three questions.1) No. The route is loaded automatically when you request the winds.2) AS16 does not know your altitude at any waypoint. The altitude is just a guess by AS16.3) Yes. Just request the winds after you have entered the STAR. However, a major part of the STAR will be traversed during descent. So the descent forecast is what applies to the STAR. Maybe the first two or three waypoints might be at your cruise altitude in which case a wind request would handle those waypoints.

In response to your answer #3, I found that the waypoints after TOD cannot receive any wind data on request. They doesn't show up in AS16 flight plan page as well. That's why I suspect that there may be bugs in either AS16 or PMDG making data link function not completed.

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In response to your answer #3, I found that the waypoints after TOD cannot receive any wind data on request. They doesn't show up in AS16 flight plan page as well. That's why I suspect that there may be bugs in either AS16 or PMDG making data link function not completed.

I just happen to be doing a T7 flight right now. All of the waypoints to landing have wind entries for 4 altitudes. The entries are for FL270, FL290, Fl330, and FL370. The waypoints in the STAR are at FL226, FL260B, FL230B, 10000, 3000A, and 2000. AS16 has the same information as the FMC. If that information is not showing up in either the FMC or AS16, you are probably doing a procedure incorrectly. Anyway it makes no difference because what applies to the 6 waypoints are the winds in Descent Forecast. Do you know how the Descent Forecast works?
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I just happen to be doing a T7 flight right now. All of the waypoints to landing have wind entries for 4 altitudes. The entries are for FL270, FL290, Fl330, and FL370. The waypoints in the STAR are at FL226, FL260B, FL230B, 10000, 3000A, and 2000. AS16 has the same information as the FMC. If that information is not showing up in either the FMC or AS16, you are probably doing a procedure incorrectly. Anyway it makes no difference because what applies to the 6 waypoints are the winds in Descent Forecast. Do you know how the Descent Forecast works?

I am sure I have done everything required for the data link function. I have checked "Auto load simulator flight plan" in AS16, and selected "CREATE AND LOAD TO P3D" in FMC. The problem is just affecting the STAR waypoints.

 

My procedure is...

1. In pre-flight stage, select and enter dep rwy, SID, and route into FMC WITHOUT selecting STAR. Then proceed WIND DATA REQUEST and DES FORECAST UPLINK

2. When approaching T/D, select STAR in FMC and confirm STAR waypoints are inserted in LEGS page, then proceed WIND DATA REQUEST and DES FORECAST UPLINK

3. The data link function is not adding wind data to those newly activated STAR waypoints, but just updating the data for non-STAR waypoints, as well as data in DES FORECAST UPLINK page

 

My procedure should not be problematic since I don't have any issue when using FSX version of PMDG 777...

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CREATE AND LOAD TO P3D

I am not familiar with P3D in terms of file and folder structure and where things should be located. I am going to need to pass on this one. Maybe some will see this topic and these posts that is conversant in P3D and answer the question. Sorry.
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The wind values on LEGS pages are not available past the TOD.

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