MadBilo

Holding behaviour seems weird...

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I think I am imputing something wrong into the FMC because it seems like the plane is doing weird turns while I am holding. 


In this scenario I was holding at DAYNE and I have been following this chart.

DQljWm_-Sp2U-xvztwO-5A.png

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

So in this screenshot I am inbound to DAYNE and everything seems normal and on the FMC you can see the figures I have inputted. V_GpgvOcRCm8DGVr9u1v7w.png

What the problem is when the plane starts turning right, it turns a lot and before the magenta line which causes it to go straight abit in the hold then start turning right again. But when this happens it makes me go out of the hold so I am on the left of the magenta line. Screenshots are here to back up and allow you guys to understand what I am saying. When I look at planes on flight radar especially the 737 it dont seem like they stop the turn and then carry on. Seems like they got a perfect turn bang on the magenta line. I also got told that real life pilots say this doesn't happen in real life too.. I was curious can I do anything to stop this from happening? It kills the immersion as its just banking left right trying to stay on magenta line. 

HvWB3KfgRFWOkzJ4Rr_7gw.pngtuPn2A0XS3SeEKUF0zEhUg.png7MYUYz_xQXG2nCPUyCtEQQ.png7Gd08D6vQ7KGlqz_JE8TkQ.png

 

Necmi Osman

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Don't be concerned about staying on the magenta line. Your speed looks good, winds are light, about the only thing I see that I don't understand is the 3 DME holding rather than 1 min holding but the alternate provisions provide for the distance rather than time so it's not a real concern.

The NGX (and most aircraft) have varying degrees of success of staying on the planned lateral path (the magenta line) during turns with large heading changes, a lot depends on speed but it's just one of many issues with the simulator's flight dynamics engine.

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5 minutes ago, downscc said:

Don't be concerned about staying on the magenta line. Your speed looks good, winds are light, about the only thing I see that I don't understand is the 3 DME holding rather than 1 min holding but the alternate provisions provide for the distance rather than time so it's not a real concern.

The NGX (and most aircraft) have varying degrees of success of staying on the planned lateral path (the magenta line) during turns with large heading changes, a lot depends on speed but it's just one of many issues with the simulator's flight dynamics engine.

That's what I thought, it may be flight dynamics engine and the limitations but I do own an different product which does not have no problem what so ever and is always on the lateral path. I was thinking maybe one day they will update the system or something? 

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Just now, MadBilo said:

That's what I thought, it may be flight dynamics engine and the limitations but I do own an different product which does not have no problem what so ever and is always on the lateral path. I was thinking maybe one day they will update the system or something? 

I don't think PMDG will ever have as a goal the intention to faithfully follow the magenta line.  I would like to see them add to the long list of things they do outside the box turning dynamics, that would be nice.  I recommend you watch some aviation radar or tracks and pay attention to what real holding patterns look like.  You will rarely see anything that represents the pretty racetrack in real life.

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18 minutes ago, downscc said:

I don't think PMDG will ever have as a goal the intention to faithfully follow the magenta line.  I would like to see them add to the long list of things they do outside the box turning dynamics, that would be nice.  I recommend you watch some aviation radar or tracks and pay attention to what real holding patterns look like.  You will rarely see anything that represents the pretty racetrack in real life.

That's the whole purpose of me being frustrated and complaining every single time, I have seen real life planes do tight heading turns right on the magenta line without no problems. 
Let me show you another scenario which I can show a real life photo too, 

Take a look at this real life planes ND gXcio9-3QPmBh66TygPWPg.png

Hard to see but you can see the magenta line perfectly and if you want here is the video link to show you it actually follows the magenta line till the captain gets HDG SEL armed
https://www.youtube.com/watch?v=_90C1ukYmXs

Here is what my PMDG shows me:

YCUPLAhsQwCZ6ky28MzaiA.png

On a note, the aircraft turns right when I reach DO8OD point when its meant to turn left...


Here is the chart: DAMAT 1L is what I am using. 
jb7B2zwDRgeZ7KotcXR3ow.png 

Might not be a big deal for people but if different aircraft can do it PMDG should be able to do it too. despite the price we pay for it..

Necmi Osman

 

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Isn't a lot of different variables to factor in, when doing turns (and especially tight turns) in the NGX - or any aircraft, for that matter?

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18 minutes ago, Anders Bermann said:

Isn't a lot of different variables to factor in, when doing turns (and especially tight turns) in the NGX - or any aircraft, for that matter?

most proberly but end of the day its all done by the FMC which does calculate these stuff. I just read my old post regarding this issue and I missed an section. It's apparently cause of PMDG's old code for the routing and FMC section. I assume they have to update the code but knowing pmdg it will not happen so got to live with it...

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The NGX does weird stuff entering holds.  I've seen this since I started using it.   It strikes me the same,  that it's an inability to precisely track the FMC computed lateral path.   It's true that it doesn't matter much in holds (in the sim, anyway) but where it matters more is in RNAV approaches,  especially RNPs with more complex lateral paths and tighter tolerances.    The real aircraft does not deviate from the track line this way.   As these types of procedures become more common,  it'll start to be more of a factor.  It's actually at the top of my list of things I'd like to see improved about the NGX, though that shouldn't be taken as much of a slight since I'm pretty impressed by everything that's been achieved already. 

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4 hours ago, Stearmandriver said:

The NGX does weird stuff entering holds.  I've seen this since I started using it.   It strikes me the same,  that it's an inability to precisely track the FMC computed lateral path.   It's true that it doesn't matter much in holds (in the sim, anyway) but where it matters more is in RNAV approaches,  especially RNPs with more complex lateral paths and tighter tolerances.    The real aircraft does not deviate from the track line this way.   As these types of procedures become more common,  it'll start to be more of a factor.  It's actually at the top of my list of things I'd like to see improved about the NGX, though that shouldn't be taken as much of a slight since I'm pretty impressed by everything that's been achieved already. 

Exactly the same way I think sir.

Necmi Osman

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