Constant left roll despite neutral rudder trim

  • I have installed v3 update for the Arrow, and also ensured that my Yoke and Rudder curves are set to default. However, the plane seems to always have a slight left roll during straight and level and I constantly have to fight the roll with a manual right roll input on my Yoke.

    I tried this in a few airports and weather conditions (wind calm) but I am still having this consistent left roll.

    Some settings I have selected:

    • Ready for takeoff
    • Save state = No (Red)
    • GPS 530
    • Auto fuel selector (have also tried manually selecting left/right with no visible difference)
    • Tablet dimmed and hidden
    • Rudder trim is set to 0 deg
    • Flight Model = Modern

    Is this the expected behavior of the plane?

  • There are real world reasons that could account for a roll to the left;

    1. Weight imbalance. If the pilot is the only person in the aircraft and fuel tanks start out with the same amount of fuel, there will be a slight tendency to roll to the left.
    2. Rudder out of trim. In real life I need to re-trim for climbs, cruise, and descent (or any time the airspeed changes). You can actually squeeze a knot or two out an Arrow by centering the slip indicator perfectly. If the ball is not centered, the plane is yawing a bit and PA28s have a small bit of roll & yaw coupling. Essentially if you are yawing left a little, the airflow over the left wing will be diminished slightly resulting in the right wing producing greater lift which results in a slight roll rate to the left.

    In real life, when flying alone I always start burning fuel from the left tank first to try and even things out. As the Arrow has no roll trim, the best you can do is use the rudder trim to offset the roll (or just use the AP in heading mode). Make sure the ball is centered. If it is and you are still rolling left, its either a flight model problem or a weight imbalance issue. Both should be solvable by using rudder trim, however if yawing was not the problem and you are using rudder trim as a solution, you might loose a tiny bit of airspeed.

  • Taking off with only the pilot's weight and both fuel tanks 50%, it rolls slightly to the left without any trim. After some flight time (or if you reduce the fuel in the left tank), it will eventually even out and then start rolling to the right.

    So from what I observe, this is just an issue of weight&balance and feels quite realistic to me.

  • Quite a remarkable thought to know the level of realism modelled here. I figured that adding 10% more fuel on the right wing more or less levelled out the left roll to compensate for the pilot's weight.