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Autopilot Not Following Glideslope w/ Latest Update


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I've been having trouble with the CRJ autopilot not following the glideslope with APPR mode on. I have tried it at RJBB RWY 24L and ENGM RWY 01L. Below is a video of it at ENGM. I thought the recent update fixed such issues but I am still having it. Before these tests I redownloaded it on the marketplace.

 

At ENGM: https://drive.google.com/file/d/1yv86YjzxRUpmRdKJamw21_Muwr21-W-j/view?usp=sharing

 

Is there something that I might be doing wrong? I'm using coupled VNAV, have the ILS frequency dialed in and APPR mode armed.

 

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I can't see the instruments well in that video. But I can't see you making any throttle changes nor was VS mode engaged at all so it seems reasonable that it didn't descend.

 

You do know this aircraft doesn't have auto-throttle, right? So you know you actually have to fly the descent yourself?

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1 hour ago, Thx1137 said:

I can't see the instruments well in that video. But I can't see you making any throttle changes nor was VS mode engaged at all so it seems reasonable that it didn't descend.

 

You do know this aircraft doesn't have auto-throttle, right? So you know you actually have to fly the descent yourself?

 

I was managing my throttle just fine, was around 185kts. I had coupled VNAV mode on. It worked fine before the recent patches.

 

Also just to say in case it might be related, when I updated it via the marketplace, the update kept redownloading for some reason, so I ended up uninstalling it completely and reinstalling it. I reinstalled it again just before making these tests today.

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So, I decided to redownload it again, but this time I watched the marketplace installer and noticed that around the 2GB mark, it jumps back to 1.7GB and keeps doing it a few more times. Eventually the download completes. However, I notice afterwards that whereas the download according to the installer is 2.83GB, the total size ends up being 1.67GB. Might this have something to do with it? Is there an issue with the marketplace downloader not updating correctly? 

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Alright so using VS mode does work fine with capturing the glideslope. I realise not many of the real aircraft have coupled VNAV. If APPR mode is not meant to work with VNAV in real life then ok, consider this topic closed.

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You should be capturing the ILS Glideslope from level flight (yes someone is going to say you can capture form above but normally you capture from bellow)...

 

OGRAS to XIKLA shows on the chart section as 3500...  Arriving at OGRAS shows a MAX 200Kt 4000' and then the segment of 3.2 miles shows 3500 to arrive at the FAF (XIKLA) to capture the GS..

 

So I would give it a go again...  lets use INSUV as the start...  Have 5000 at INSUV and 200 or below speed...  dial in 4000 and Descend with VS.

 

Once 4000 is captured you can dial in 3500.... but not press VS yet.... it won't start down on you.  once you hit OGRAS press VS and descend to 3500.. Once levelled off you should be able to dial in the missed approach altitude of 5000.. press APPR and it will ARM GS in white and will probably instantly go into LOC..... as you reach XIKLA GS should go green and it will start down... once it starts down if you did not dial up your Missed ALT you can do it now as well...

 

image.thumb.png.fff01b4d621f321ac792c1073bfae598.png

 

 

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I have been intercepting the GS without problems; the issue I'm seeing is that at some point after capture the horizontal bar of the Flight Director seems to "lose the plot" and stops giving me any useful advice on how to fly the approach. As you can see in the attached image, I've already started pushing my nose down to chase the diamond but the FD is telling me to fly level...which it had been doing and continued to do even as the diamond went lower.

 

I'm not a 'great pilot', in fact I am awful but as far as I can tell in the situation depicted in the screenshot there is no reason why the FD should be telling me this...unless in the background it still thinks it should be trying to level off at 2700ft which is the GS intercept altitude at BURNY. If I'm doing something wrong I'm happy to learn.

 

For now the plane is largely unflyable for me in anything but VMC, which is sad because I'm really starting to master the descent without VNAV and a crazy stormy approach like this one down into Atlanta would have been incredibly fun were I not trying to fly it on raw data and a broken FD :(

 

 

Glideslope.thumb.JPG.bbf55d0bc58b686d3b2fffd36dcad429.JPG

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56 minutes ago, LesOReilly said:

 

 

 

 

 

 

Thank you for that Les. I did test that and it worked well. So what I'm gathering here is that just using in the autopilot coupled VNAV mode with APPR armed won't capture the glideslope. Instead I need to be either in ALT mode or VS mode.

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8 minutes ago, Matt S said:

I have been intercepting the GS without problems; the issue I'm seeing is that at some point after capture the horizontal bar of the Flight Director seems to "lose the plot" and stops giving me any useful advice on how to fly the approach. As you can see in the attached image, I've already started pushing my nose down to chase the diamond but the FD is telling me to fly level...which it had been doing and continued to do even as the diamond went lower.

 

I'm not a 'great pilot', in fact I am awful but as far as I can tell in the situation depicted in the screenshot there is no reason why the FD should be telling me this...unless in the background it still thinks it should be trying to level off at 2700ft which is the GS intercept altitude at BURNY. If I'm doing something wrong I'm happy to learn.

 

For now the plane is largely unflyable for me in anything but VMC, which is sad because I'm really starting to master the descent without VNAV and a crazy stormy approach like this one down into Atlanta would have been incredibly fun were I not trying to fly it on raw data and a broken FD :(

 

 

Glideslope.thumb.JPG.bbf55d0bc58b686d3b2fffd36dcad429.JPG

 

This is a known issue which I thought was fixed with the latest update 1.0.0.5. I haven't had a chance to try it out but the good news is that the FD issue does not affect the autopilot so if you leave the autopilot engaged it should fly the ILS perfectly. That may not be what you're looking for right now but it's a work around.

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22 minutes ago, Chaxterium said:

 

This is a known issue which I thought was fixed with the latest update 1.0.0.5. I haven't had a chance to try it out but the good news is that the FD issue does not affect the autopilot so if you leave the autopilot engaged it should fly the ILS perfectly. That may not be what you're looking for right now but it's a work around.

 

I think that's a different problem that seems to have been fixed - FD displayed consistently a bit too low.

 

This issue I'm getting is the FD annunciator says that the LOC and GS are captured but it is doing something altogether different in the background. In the vertical plane, at least.

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I believe I may have narrowed the issue down...

 

Just did a flight where I captured the LOC and GS while on autopilot at 2000', and it began tracking it with no problem. Then, I turned off the AP at about 1500' and hand-flew according to the FD, which failed to provide accurate guidance (drove me below the GS diamond again).

 

I quickly clicked "APPR" off and on again, and the FD guided me right back up to capture the diamond.

 

I will do some more testing but I think that turning the AP off after capturing the GS is secretly placing the FD into PITCH mode, without giving an annunciation.

 

 

 

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10 hours ago, Matt S said:

I have been intercepting the GS without problems; the issue I'm seeing is that at some point after capture the horizontal bar of the Flight Director seems to "lose the plot" and stops giving me any useful advice on how to fly the approach. As you can see in the attached image, I've already started pushing my nose down to chase the diamond but the FD is telling me to fly level...which it had been doing and continued to do even as the diamond went lower.

 

I'm not a 'great pilot', in fact I am awful but as far as I can tell in the situation depicted in the screenshot there is no reason why the FD should be telling me this...unless in the background it still thinks it should be trying to level off at 2700ft which is the GS intercept altitude at BURNY. If I'm doing something wrong I'm happy to learn.

 

For now the plane is largely unflyable for me in anything but VMC, which is sad because I'm really starting to master the descent without VNAV and a crazy stormy approach like this one down into Atlanta would have been incredibly fun were I not trying to fly it on raw data and a broken FD :(

 

 

Glideslope.thumb.JPG.bbf55d0bc58b686d3b2fffd36dcad429.JPG

 

here you are not on a stable decent. That speed with that high throttle setting isn't matching the natural flight characteristics. N1 should be around 58- 63%. the plane does not have an autothrottle.

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3 hours ago, Danny Vincken said:

 

here you are not on a stable decent. That speed with that high throttle setting isn't matching the natural flight characteristics. N1 should be around 58- 63%. the plane does not have an autothrottle.


True, but irrelevant. The purpose of the screenshot was to illustrate how the horizontal FD bar 'froze' in that position after I turned off the autopilot.

 

After the incident shown, I did another test flight under carefully controlled conditions and established conclusively that poor flying is not the cause of this FD failure:

 

- The test approach was initially stable after capturing the LOC and GS on autopilot.

 

- As soon as I disconnected the AP, the FD bar 'froze' and stayed in the same position regardless of how the ILS diamond was moving.

 

- I intentionally followed the erroneous indication for several seconds to see if it would correct itself, but it did not. This left me well below the glideslope.

 

- After I cycled the Approach button off and then on again, the FD "woke up" and had no problem at all guiding me back to the approach path. By that point the aircraft was quite unstable in both position and speed and the FD was perfect.

 

This behavior leads me to suspect that the FD is degrading to PITCH mode on approach without telling anyone (in this case, when I turn the AP off).

 

This may also be happening when the AP is engaged on the initial climb, after I had been previously following the FD in IAS mode. I will test it further.

 

My recommended workaround in the meantime is to always re-select the desired FD vertical mode immediately after turning the AP on or off.

 

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  • 2 weeks later...
On 5.6.2021 at 23:48, Matt S sagte:

I have been intercepting the GS without problems; the issue I'm seeing is that at some point after capture the horizontal bar of the Flight Director seems to "lose the plot" and stops giving me any useful advice on how to fly the approach. As you can see in the attached image, I've already started pushing my nose down to chase the diamond but the FD is telling me to fly level...which it had been doing and continued to do even as the diamond went lower.

 

I'm not a 'great pilot', in fact I am awful but as far as I can tell in the situation depicted in the screenshot there is no reason why the FD should be telling me this...unless in the background it still thinks it should be trying to level off at 2700ft which is the GS intercept altitude at BURNY. If I'm doing something wrong I'm happy to learn.

 

For now the plane is largely unflyable for me in anything but VMC, which is sad because I'm really starting to master the descent without VNAV and a crazy stormy approach like this one down into Atlanta would have been incredibly fun were I not trying to fly it on raw data and a broken FD :(

 

 

Glideslope.thumb.JPG.bbf55d0bc58b686d3b2fffd36dcad429.JPG

Seems, the same "issue" I had yesterday

Regards, Herbert

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