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V1.1.2: Phugoid oscillation during AP ILS


Fab10

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Thank you for the latest update, I'm pleased that the IB A300 is edging ever closer to perfection.

I have complete two ILS approaches in it and both times the aircraft began an ever increasing longitudinal phugoid oscillation with the AP engaged.

I was not yet at Vapp but I was nearly fully configured with one stage of flap to extend.

Both times this occurred early in the approach with several miles still to run; my preference is to hand fly without AT which also helped to dampen and remove the oscillation.

I thought to report this in case others have noted the same.

Thanks.

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For what it's worth, I uploaded a short video of this phenomenon (below).

Also, please could INI Builds adjust the WXR 1/off/2 switch whose operation is reversed, and rejig the yoke that seems to move excessively and disproportionately to the actual bank angle of the aircraft (as it gets in the way of instruments and dampens immersion).

The V1.1.2 update has been great otherwise (though I've yet to test RNAV), and I'm also grateful for the terrain radar and t/o trim indication on the EFB takeoff perf page.

 

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14 hours ago, Fab10 said:

Both times this occurred early in the approach with several miles still to run; my preference is to hand fly without AT which also helped to dampen and remove the oscillation.

28 minutes ago, Fab10 said:

For what it's worth, I uploaded a short video of this phenomenon (below).

Thanks we'll look into it.

28 minutes ago, Fab10 said:

Also, please could INI Builds adjust the WXR 1/off/2 switch whose operation is reversed,

This is an issue with the Asobo's interaction system in LEGACY interaction mode. As of v1.1.2, we rewrote the XML interactions for all switches from the ground up their  template in order to optimize performance. However the issue is that it causes the interaction to be reversed in LEGACY vs LOCKED interaction system, specifically an issue with 3-way switches. There's not much we can do about it at the moment, however whenever possible we'll implement a fix in future updates.

31 minutes ago, Fab10 said:

rejig the yoke that seems to move excessively and disproportionately to the actual bank angle of the aircraft (as it gets in the way of instruments and dampens immersion).

The movement is modelled based on observations and data from movements in full-motion simulators and real world counter part of this aircraft. If you find this to be an issue you may click the base of the yoke to hide it completely from view.

Thanks!

Vrishabh Sehgal @Richboy2307 )
Community Team Member & Tester
IniBuilds Ltd. | inibuilds.com

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30 minutes ago, richboy2307 said:

The movement is modelled based on observations and data from movements in full-motion simulators and real world counter part of this aircraft. If you find this to be an issue you may click th

Yes, it is an issue, and cannot reflect real world yoke movements. The yoke obscures the instruments, breaks immersion, and if the yoke is hidden then disconnecting the AP can be frustrating as one needs to restore the yoke to switch off the AP DIS sound.

To illustrate how spurious the yoke movements can be, please check my approach in this video (from 01:24):

 

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At 1:03:16 when you point out the excessive yoke movements it did look ok-ish to me. I'm in fact quite more stunned about how the autopilot tries to maintain the heading of 082 and then going into the left turn (after 1:05:30). It seems to me as if the autopilot fights against some extreme adverse input from either manual yoke movements (wouldn't the autopilot disconnect?) or turbulences (what are your turbulences settings?). On the final approach when you are hand-flying the aircraft the yoke movements are indeed extreme but seem to relate to the control inputs. Looks like the yoke calibration is a bit too aggressive - maybe recalibrate or reduce sensitivity.

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Well, I managed to post the wrong link above in my second post (LYTV to LRTM) instead of the mini loop MGMM-MGMM. Not sure how I managed that!

Heres the right link:

 

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On 7/27/2024 at 2:28 PM, Fab10 said:

Heres the right link:

Thanks I see the oscillations. What was your FPS at the time? Low FPS can mess with the autopilot functions. I believe a minimum of 23 is required, below which there can be latency in calculation that leads to excessive inputs/overcorrection.

Also can you ensure you have all the assists disabled (Options > Assistance Options > Piloting)? These can cause issues with AP inputs.
Also recommend a turbulence setting of MEDIUM or LOW, especially in mountainous areas such as where you're flying as the mechanical turbulence effect on large aircraft is unfortunately bit too exaggerated in the sim at REALSTIC setting.

image.thumb.png.597a1125938287e5199374479f3868d0.png

 

On 7/26/2024 at 9:57 PM, Fab10 said:

Yes, it is an issue, and cannot reflect real world yoke movements. The yoke obscures the instruments, breaks immersion, and if the yoke is hidden then disconnecting the AP can be frustrating as one needs to restore the yoke to switch off the AP DIS sound.

Owing to probably one of the above reasons, your yoke input appears far more excessive than experience by me personally in testing and flying this aircraft. The yoke blocking the instruments however, is an issue even in the real aircraft so you can either adjust your view point, or simply hide the yoke as recommended above if it is an issue,

With regards to the AutoPilot, you can bind a key command to your keyboard, mouse or controllers to commands such as TOGGLE DISENGAGE AUTOPILOT or AUTOPILOT OFF such that you won't have to bring up the yoke again. Click the command twice to silence the AP Disconnect wailer.

Thanks!

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Vrishabh Sehgal @Richboy2307 )
Community Team Member & Tester
IniBuilds Ltd. | inibuilds.com

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  • 2 weeks later...

FPS Locked at 30 on VSYNC without fluctuations on a RTX3080 and Ryzen 9.

The oscillations still occur, indeed it recurred again today at LFML RW31R, if the AP manages the initial descent but the moment the AP is switched off the aircraft ceases the pitch oscillation.

Yes, the speed is very slightly higher than Vref as often approaches are flown at 160 kts or thereabouts depending on traffic to then slow at 4 nm or so.

Please stop calling out the piloting abilities of your loyal customers and begin reading and, more importantly, processing what is written in their communications, as they have taken the time to communicate the issue to you in the hope that INI Builds will read, understand and appreciate instead of seemingly always taking a defensive line.

Beginners are most unlikely to purchase such an in-depth old school airliner whereas a knowledgeable connoisseur will.

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2 hours ago, Fab10 said:

Yes, the speed is very slightly higher than Vref as often approaches are flown at 160 kts or thereabouts depending on traffic to then slow at 4 nm or so.

Please stop calling out the piloting abilities of your loyal customers and begin reading and, more importantly, processing what is written in their communications, as they have taken the time to communicate the issue to you in the hope that INI Builds will read, understand and appreciate instead of seemingly always taking a defensive line.

Beginners are most unlikely to purchase such an in-depth old school airliner whereas a knowledgeable connoisseur will.

Maybe I'm missing some context here, but not sure what you're replying to here. None of the posts above are referring to speed, nor calling out your piloting ability, especially any posts by an iniBuilds staff/representative. 

In any case, can you please confirm you have followed the above suggestions? I have read your post and relayed to you that such oscillations have not been observed by us internally throughout testing, nor reported by our wider testing group of users. As such it is possible the issue is localized based on certain setting or configuration on your sim or control setup. 

All of the above suggestions are based on previous user reports / identified conflicts. They are mentioned for you to try and help eliminate possible factors. 

There is nothing here about being defensive, but rather relaying to you what our experience has been, and how we're not able to reproduce the issues you're facing on our end, so trying things to get to the bottom of it.

Thanks!

Vrishabh Sehgal @Richboy2307 )
Community Team Member & Tester
IniBuilds Ltd. | inibuilds.com

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I experienced this for the first time as well the other day.  However, I was on approach to MMMX (Mexico City), still turning to the IAF.  I had the ILS tuned, but had not activated the V/L or LAND buttons.  I was in the bank from VOLUN to MX901, when it started bouncing up and down.  It finally settled down on its own in time to arm the ILS modes and land properly.  Turbulence on low, PROF armed, no traffic around me (late at night), no visible weather changes.

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15 hours ago, Orlaam said:

I experienced this for the first time as well the other day

Thanks for the report. Can you specify the full route used (along with SID/STAR/APP) as well as planned ZFW, Fuel load & Cost Index to see if we can reproduce the issue with those exact parameters. Both instances appear to be high altitude airfields, near hilly terrain, so warrants a test.

However for transparency, I've tried the approaches at MGMM and LFML already twice without issues on my end personally.

Thanks!

Vrishabh Sehgal @Richboy2307 )
Community Team Member & Tester
IniBuilds Ltd. | inibuilds.com

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