logged Autopilot V/S-Mode Causes Pitch Jerk/Overshoot and V/S Deviation (v1.1.6, MSFS 2024)

[IndiaAlpha]

I’ve encountered a noticeable autopilot behavior issue when transitioning to/from Vertical-Speed-Mode and wanted to share a report with video evidence to help improve it. I enjoy flying the aircraft, but this issue annoys me quite a bit, so I need to address this.

Description: When transitioning the autopilot from any flight mode (e.g., managed climb/descent or open climb/descent) to Vertical-Speed-Mode by pulling the VS/FPA knob, the aircraft exhibits non-realistic behavior:

• The pitch attitude jerks or twitches abruptly before stabilizing.
• The vertical speed overshoots the commanded value by 200-400 fpm (either up or down) before settling (e.g., commanding -2000 fpm results in temporary -2400 fpm or lower).
• This twitching/jerking also occurs when switching back to other modes (e.g., open descent/climb).

Expected Behavior: Immediate capture of current VS with smooth pitch adjustment, no overshoot or jerking, as per real Airbus fly-by-wire logic. The sim's response introduces unnecessary instability and unrealistic behavior.

Steps to Reproduce:

1. At a stable climb/descent (e.g., +2000 fpm), pull the VS/FPA knob to engage VS mode with the current VS displayed/targeted.
2. Observe: Pitch jerks (up/down by 2-3°), VS deviates (e.g., +2000 fpm becomes +2300 fpm temporarily), then settles after 5-10 seconds.
3. Disengage VS (switch modes) and note the twitching on re-engagement.

Tested in:

• iniBuilds A350 Airliner v1.1.6
• MSFS24 Version SU3 1.5.27.0 
• clear weather (clear skies template) & live weather
• turbulence setting low & medium & realistic
• consistent across multiple flights 
• no mods/add-ons interfering

Attachments:

https://youtu.be/S7M8ml1QL4M?si=ZAFmacTaU0Rt6_g7

 

[richboy2307]

Thanks issue is logged.