Better trim for air-start missions

[LeCuvier]

When you start a mission in the air, the nose goes brutally down and left. You need to apply a lot of rudder -right and nose-up trim, plus a bit of aileron trim before you can fly her with any level of precision. In an instant action mission you may already be under fire before you are done trimming, and before you can make any adjustment to target wingspan and range, let alone worrying about engine settings.

The P-47D should have at least approximately correct trim settings when the mission starts airborne.

[joker68]

Yes, this is a PITA. For now, the only way I know to get around this is to instantly active pause the mission after starting it and then proceed to adjust the controls. 

[Gunfreak]

Yes, this is extremely annoying. Makes doing instant missions like dogfight or furball impossible, by the time you've trimmed you'll have 3 germans on your six.

 

 

[Jakey-Poo]

Not to mention that the trim wheel selection is way too coarse when compared to the P-51, Spit, etc.  Much harder to make fine adjustments in this aircraft.  I once fixed this with the LUA file, but can't find the link anymore.

[LeCuvier]

I reduced the "gain" parameter for the 3 trim wheels from 0.025 to 0.0125 in the file "clickabledata.lua" in the folder "...\DCS World OpenBeta\Mods\aircraft\P-47D-30\Cockpit\Scripts".

Here is the block of lines with the 3 modified lines:

           -- Aileron Trim Wheel
            elements["pnt_91"] = cabin_axis_limited(0, _('Aileron Trim'),  devices.CONTROLS, device_commands.Button_1, 91, 0.0, 0.0125, false, false, {-1.0, 1.0}, {135, -45}, {45, -45})-- HWF changed Gain from 0.025 to 0.0125
            elements["pnt_91"].sound = {{SOUND_SW5}}
            -- Elevator Trim Wheel
            elements["pnt_92"] = cabin_axis_limited(0, _('Elevator Trim'), devices.CONTROLS, device_commands.Button_4, 92, 0.0, 0.0125, false, false, {-1.0, 1.0}, {-135, -20}, {-45, -30})-- HWF changed Gain from 0.025 to 0.0125
            elements["pnt_92"].sound = {{SOUND_SW5}}
            -- Rudder Trim Wheel
            elements["pnt_93"] = cabin_axis_limited(0, _('Rudder Trim'),   devices.CONTROLS, device_commands.Button_7, 93, 0.0, 0.0125, false, false, {-1.0, 1.0}, {135, -45}, {45, -45})-- HWF changed Gain from 0.025 to 0.0125
            elements["pnt_93"].sound = {{SOUND_SW5}}

 

[Jakey-Poo]

6 minutes ago, LeCuvier said:

Here is the block of lines with the 3 modified lines:

Thanks!  This is exactly what I was referring to.  I had to uninstall/reinstall DCS a month or so back, and immediately noticed the difference in trim performance.  Hopefully they fix this within module, so we can stop modifying lua files.

[LeCuvier]

Back to the original subject of this thread:
I was tired of having to mess with a lot of trimming at the start of airborn missions, so I figured something out.

1. all 3 trim wheels are in their center position when the mission starts.

2. Elevator trim must be more tailheavy, rudder needs a lot of yaw-right trim, and ailerons need a bit of right-wing down trim.

3. I determined, by trial and error, which action values would be required for the trim axes and found:

    Elevator = -0.4
    Rudder   = 0.2
    Ailerons = -0.15

Note: the action value for the center or "neutral" position is = 0.

I created a key command (to be bound to a pushbutton or keyboard key) that combines the 3 action values. This line of code is added to my "default.lua":

{down = device_commands.Button_6, pressed  = device_commands.Button_9, up = device_commands.Button_3, cockpit_device_id = devices.CONTROLS, value_down = -0.4, value_pressed = 0.2, value_up = -0.15, name = _('Elevator_Rudder_Aileron Trim Preset'), category = {_('Flight Control')}}, 

This creates a new command "Elevator_Rudder_Aileron Trim Preset" which I bound to a button on my joystick. Immediately after mission start I hit this button and from there I have very little trimming to do. (at about 300 knots IAS)

Those who don't mind modifying the "default.lua" are welcome to try this solution.

Edited August 24, 2021 by LeCuvier