HGS Issue With Taxi Light

Hello! I recently realized I wasn't running the latest version of the Pro Q400, so uninstalled it and installed the new version. Everything is working well, except I now have an odd bug.

Whenever the taxi light is on, the brightness of the HGS maxes out - this didn't happen with my previous installation. Is this a known bug with a known fix?

Thanks for any help!


  • Just wanted to provide a quick update: I've since noticed that the taxi and landing lights do not illuminate the ground in the external view. From the cockpit, both taxi and landing lights do illuminate the ground.

    This was also not present in my previous installation. Any ideas? Thanks!

  • edited January 2022

    I found the following thread with a quick forum search:

    Could the suggestion in that thread (MOON_PHASE_LIGHTING=False) perhaps help?

    = - = - = - = - = - = - = - = - = - = - = - = - = - = - =

    If the above doesn't help, then you may need to give some extra information ... Is this with FSX or P3D? If P3D, what version of P3D? Do you have the Dash 8 Visual Package installed? Are you using any third party shader programs? Is this at a default airport, or a third-party airport? Do you have Dynamic Lighting on? Do you have HDR on? etc etc.

  • Unfortunately, that did not fix the issues. I also just uninstalled and reinstalled the airplane, which also yielded no improvements.

    Right now I'm running the latest version of P3D 4.5 with no third party shaders. The Q400 is the Pro edition without the Visual Package, and it is happening at all airports. I don't have dynamic lighting or HDR on.

  • Are you experience the same issue with HDR on?

    I am not running 4.5 but will check and see if I can replicate in 5.3.

    This would not necrssisaliy be considered a bug as the HGS still functions but P3D does have certain flaws that are not always to work around.
  • Yup, I tried both HDR on and HDR off. Having HDR on actually makes the issue worse:

    To try and solve the problem I completely uninstalled P3D and all addons, then installed nothing but the latest version of P3D, FSUIPC, and the Q400. Unfortunately, the problem still persists.

  • I have tested this issue that you are experiencing and have not been able to replicate. Out of curiosity do you have bloom enabled?

  • In that screenshot, I had bloom on. However, I tried various combinations of HDR, bloom, and dynamic lighting. The issue persists, regardless of settings. This is on the latest version of P3D 4.5, so not sure about P3D 5.3.

  • Copy, we are still looking into the issue.


  • edited February 2022

    This may be a help for Kroswynd ... here is a comparison screenshot.

    Like you, I'm running the latest version of P3D 4.5 with no third party shaders. My Q400 is the PRO Edition (v1.024) without the Visual Package.

    However, in my sim, I do have HDR enabled and Dynamic Lighting on.

    The HGS brightness does not appear to be maxed out for me. I do notice that your landing light does appear to be brighter on the ground than mine. Could this be a monitor setting (brightness or contrast control on the monitor), perhaps?

    And, it might seem obvious, but does your HGS brightness adjust when you use the HUD BRT (brightness) dial?


  • Thanks for the responses.

    The HGS knob does work for me - in fact, when I turn on the taxi light and the brightness maxes out, I can use the knob to bring it down to normal. However, when switching the taxi light off, I then need to turn the knob way up again to get the brightness back to normal.

    Definitely not a monitor setting - the brightness only goes way up on the HUD when the taxi light is on. The super bright taxi light was only when I had bloom on.

    Very strange issue, indeed.

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