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Plane keeps zigzagging when meeting a waypoint


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Good day everyone.

 

I recently bought the CRJ and I am really happy of the result. Thank you to the team for the work. 

 

I’m having trouble in flying the CRJ. Sorry in advance if the problem was already treated elsewhere. I tried to search a solution on the FAQ and forum but didn’t find anything at the moment. 

At cruise in navigation mod, following the flight plan's route when the plane meets a waypoint and change its trajectory, the angle of banking is not right as the aircraft keeps zigzagging before finding its right heading. 

FD / AP / NAV / ALT are on. I tried turning on and off 1/2 bank but still nothing. The problem disappears when switching NAV to HDG mod.   

I am using modern flight mod.

I followed during weeks The Dude videos. 

 

Thank you for your help.

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It would be nice if Aerosoft team could comment on whether this LNAV issue is which is documented by many users has been understood and corrected with the latest world update? Or will there be a further update to the CRJ in the future to correct this behavior?

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We seriously doubt the world update will change anything. 


We are still trying to understand why the LANV issue is problematic for some users (we now have 17 confirmed cases)

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Me too.

The bank angle is often 30 degrees no matter the correction required which may be why the aircraft overshoots the required LNAV path and then tries to correct but overshooting again.

It reminds me of PID loop not being correctly tuned.

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Well, Number 23 here.

For me it looks like turn anticipation comes way too early, then the inevitable lateral offset needs correction. Which is done too aggressive with 30deg bank S-turns. Setting it to 1/2BANK helps a bit, but then the correction often takes way too long, sometimes up to the next waypoint.

 

 That's not a new problem though, it plagues the CRJ since the first P3D version and got only marginally corrected.

 

Mike

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2 hours ago, Danny875 said:

Me too.

The bank angle is often 30 degrees no matter the correction required which may be why the aircraft overshoots the required LNAV path and then tries to correct but overshooting again.

It reminds me of PID loop not being correctly tuned.

#24 here

 

I would second that message, I don't have the feeling 1/2 banks make any difference, the plane always applies a steep angle during the turn and is too slow to correct or to anticipate. It's actually better to use HDG for anything more than 45 degrees turn and revert to NAV afterwards.

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Add me to the list of those who experience this issue, though it hasn't stopped me from flying (and thoroughly enjoying) the CRJ.  To be specific about what I see:

  • The aircraft will often turn too early when approaching a waypoint, especially when the next course is >45-degrees from the current course.  It will bank at 30-degrees to turn to the new heading, but have a cross track error of 1-1.5 nm after rolling wings level.  It will then attempt to correct the cross track error by banking 30-degrees the opposite direction, resulting in a decaying oscillation back to course (e.g. underdamped controller).  In most cases, this resolves itself within ~1 minute (on the right course with no oscillation). 
  • The zig-zag will occur continuously with headings close to north and a crosswind.

 

Please let me know if there is additional information or testing that will help you dig into this problem.

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Hans is trying to reproduce this issue but so far has not managed. It is absolutely not forgotten.

 

If there is anybody who can reliably recreate this please send Hans the details via PM.  But to avoid losing a lot of time make sure you can actually recreate the problem yourself.

 

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Hello,

 

Last night I flew from KMCI to KMSP and along the route, I had my autopilot set to “Nav” which followed the waypoints just fine but every 10 nm between waypoints, the plane would make 30 degrees turn to get back on the track. I had 80 knots crosswind. I thought that turn was very excessive and very frequently. 
 

The route: ROYAL9 TONCE ROKKK NITZR3

 

I did made two trips on the same route and it’s doing the same thing. So I switched from “Nav” to “hdg” and manual turn headings to each waypoints to my destination. 
 

Thought I’d let you know if you are able to reproduce the same issue as me?
 

Thanks

Brian

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12 hours ago, flyingpogo22 said:

Hello,

 

Last night I flew from KMCI to KMSP and along the route, I had my autopilot set to “Nav” which followed the waypoints just fine but every 10 nm between waypoints, the plane would make 30 degrees turn to get back on the track. I had 80 knots crosswind. I thought that turn was very excessive and very frequently. 
 

The route: ROYAL9 TONCE ROKKK NITZR3

 

I did made two trips on the same route and it’s doing the same thing. So I switched from “Nav” to “hdg” and manual turn headings to each waypoints to my destination. 
 

Thought I’d let you know if you are able to reproduce the same issue as me?
 

Thanks

Brian

There is a known issue where the aircraft will oscillate left and right with a crosswind when the course heading is very close to north, which I have posted on our internal bug tracker. I loaded your flightplan above into Foreflight, and it shows the leg from JDOGG to TRONCE is 357 degrees, and from TRONCE to ROKKK is 359 degrees, so those two legs would likely be subject to the problem. 
 

The cause for this is under investigation.

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I made a side-by side comparison on my Desktop and Laptop of the CRJ in P3Dv5 and MSFS, a flight exactly parallel. While LNAV in P3Dv5 is not perfect either, in the latest CRJ version it is definitely better than in MSFS now. The main reason might be the turn radius, it is much tighter now in MSFS than in P3D. I remember that incorrect turn radius was always an issue in FSX, then carried over to P3D.

So I'm wondering, has the CRJ LNAV being carried over from the P3D version straight into MSFS ? Looks like the now correct turn radius leads to the wrong turn anticipation now (see the screenshot above, I exactly made the same observationa).

If the turn anticipation goes that wrong, it makes the entire turn look bad, because the lateral offset inevitable needs correction then.

However, just a thought...

 

Unfortunately I can't contribute with details how to reproduce this. I see the problem on every flight.

 

Mike

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Having read the recent bank angle post I’m just wondering out loud whether the issue is bank angle/ anticipated bank angle related in some way?

Most people reporting this issue (me included) would say that the flight director is commanding a set turn but the rate commanded is too much too soon.

This leaves the flight director behind the curve because it now has to correct the early turn by turning away, this then further increases the error...

Is the bank angle commanded initially too high?

What if it were limited to the anticipated turn rate?

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Yes .... i just asked in that same bank angle post 😬

 

During my last flight bank angle was ON ... FL370 ... but despite  that the CRJ  banked at 30 degrees

 

with ever sharper turn at a waypoint it wobbled...

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vor 1 hour , DGH sagte:

Yes .... i just asked in that same bank angle post 😬

 

During my last flight bank angle was ON ... FL370 ... but despite  that the CRJ  banked at 30 degrees

 

with ever sharper turn at a waypoint it wobbled...


1/2 Bank does not activate in NAV mode. Seems to be a bug. Whenever you (or the aircraft) turn 1/2 Bank on or off, switch to HDG mode and right back to NAV. 

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@Hans Hartmann

@Mathijs Kok

 

hi gents

 

Any estimated ETA on an patch / update ?

 

yesterday i had a flight with the north / crosswind wobble AND wobble at almost every turning waypoint.

 

the combination between the 2 wobble issues... is a lot of wobbling during one flight !

 

( this is costing my airline a huge amount of vomit bags 😬 )

 

keep up the good work 👍

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5 hours ago, DGH said:

@Hans Hartmann

@Mathijs Kok

 

hi gents

 

Any estimated ETA on an patch / update ?

 

yesterday i had a flight with the north / crosswind wobble AND wobble at almost every turning waypoint.

 

the combination between the 2 wobble issues... is a lot of wobbling during one flight !

 

( this is costing my airline a huge amount of vomit bags 😬 )

 

keep up the good work 👍

The s-turning on headings close to north with a crosswind is under active investigation by Hans and the test team. No solution yet - development got a bit sidetracked due to issues caused by the 1.5.0.7 sim update, but this is definitely being looked at.

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1 minute ago, JRBarrett said:

The s-turning on headings close to north with a crosswind is under active investigation by Hans and the test team. No solution yet - development got a bit sidetracked due to issues caused by the 1.5.0.7 sim update, but this is definitely being looked at.

 

And the wobbling at waypoint turns ? 
 

like i said ... its a combi that can make some flights horrible

 

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