P3D v1 Auto Trim?

[lionheart]

Hey all,

Is there a command that can instantly trim a plane out? Like auto-trim or the like? Normally, for me, in the sim, I select auto-pilot with heading and alt selected and its trimmed in a short while. But wondering if there is something that does this instantly and quicker.



Many thanks for any input.



Bill

 

[taguilo]

Bill,

There is a command for trimming the aircraft to its current pitch attitude:

K:AP_ATT_HOLD_ON

Is this what you're looking for?

Tom

 

[Flusirainer]

 <Element>
    <Select> 
      <Value> 
           (A:AUTOPILOT MASTER,percent) 50 &gt;  
           (A:AIRSPEED TRUE, kilometer per hour) 600 &gt; and
           (A:VERTICAL SPEED, meters/second) 3.5 &lt; and
           (A:VERTICAL SPEED, meters/second) -3.5 &gt; and
           (A:ELEVATOR POSITION, percent) -5 &gt; and   
           (A:ELEVATOR POSITION, percent) 5 &lt; and 
           (A:AILERON POSITION, percent) -25 &gt; and   
           (A:AILERON POSITION, percent) 25 &lt; and 
           (A:INCIDENCE BETA, degrees) -0.1 &gt; and   
           (A:INCIDENCE BETA, degrees) 0.1 &lt; and 
           (A:G FORCE, G Force) 1.5 &lt; and  
           (A:G FORCE, G Force) 0.5 &gt; and  
           (A:GEAR CENTER POSITION, percent) 1 &lt; and
              if{ (&gt;K:AP_ALT_HOLD_ON) }  els{ (&gt;K:AP_ALT_HOLD_OFF) }
      </Value>
    </Select>
  </Element>

aircraft.cfg

[autopilot]
autopilot_available=1
flight_director_available=0
default_vertical_speed=0.000000
autothrottle_available=1
autothrottle_arming_required=0
autothrottle_takeoff_ga=1

 

[jeroen79]

What exactly do you mean by 'trimming out'?

The purpose of trim is to reduce the force the pilot has to exert on the controls.
So trimming out would mean adjusting trim until the deflection of the main controls is zero.

Altitude and attitude hold are autopilot modes that adjust the elevator to maintain a specific altitude or attitude.
The autopilot also adjusts the trim to reduce the workload on the elevator servo.
An additional benefit is that when the autopilot is disengaged the pilot will not have a sudden and large force on his controls and the plane will not suddenly depart from what it was doing on autopilot.

Do you want an autopilot that maintains speed/altitude/course/whatever?
Or do you want something that will autotrim so that the pilot can fly the aircraft by the maincontrols alone and have the trim adjust itself so that the pilot will be able to gradually recenter the controls if he manouvers the plane into a different flightmode?

Both can be done by a PID loop.
The input would be the desired state and the actual state.
It's output could be trim_speed and that would be fed into an integrator that sets the new trim position.

 

[taguilo]

Altitude and attitude hold are autopilot modes that adjust the elevator to maintain a specific altitude or attitude.
The autopilot also adjusts the trim to reduce the workload on the elevator servo.

This is ok in RL, but FS autopilot does not handle the elevators, all kind of vertical control is managed through the elevator trim. So, selecting a pitch attitude On will make the elevator trim to quickly reposition as to maintain the current pitch.

Tom

 

[lionheart]

Thanks Tom! That will work.

Thanks Flusi! Goodness, that's the entire list, man!

Jeroen, 'to place the aircraft in a state of requiring very minimum control'. What I can do with the attitude command is run a timer with it, then release it (shut it off) and it should be flying true and balanced without the AP system on.


Thanks guys.


Bill