Yaw Damping Gain (YAW2SRV_DAMP)

Description

YAW2SRV_DAMP is the primary tool for stopping a plane's tail from "wagging."

In a fixed-wing aircraft, aerodynamic forces or sudden wind gusts can cause the tail to swing left and right (Yaw Oscillation). This parameter applies a counter-force via the rudder based on the yaw rate measured by the gyro. It "resists" fast rotation on the yaw axis, leading to a much smoother and more stable flight path.

Tuning & Behavior

• Default: 0 (Disabled).
• Recommendation: Start with 0.1 and increase in small increments.
• Optimal Setting: The plane should fly straight and true, even in turbulent air, without any noticeable oscillating or "hunting" behavior from the rudder.
• Dependency: This should be tuned after setting the basic rudder mix (KFF_RDDRMIX).

Yaw Integrator Limit (YAW2SRV_IMAX)

Description

YAW2SRV_IMAX prevents the "Integrator Windup" problem.

The integrator (YAW2SRV_INT) slowly adds rudder trim to correct for persistent errors. However, if this value can grow too large, the rudder might get "stuck" over to one side for a long time even after the error is gone. This parameter sets a hard limit on how much the integrator can move the servo.

• 1500 (Default): Allows up to 15 degrees of rudder trim (approx 1/3 of total travel).

Tuning & Behavior

• Recommendation: Leave at 1500. If your plane needs more than 15 degrees of constant rudder to fly straight, you have a major mechanical build issue.

Sideslip Control Integrator (YAW2SRV_INT)

Description

YAW2SRV_INT (Integral) eliminates long-term steady-state sideslip.

While YAW2SRV_DAMP reacts to sudden movements, and YAW2SRV_SLIP reacts to lateral forces, the Integrator term looks at persistent errors. If the plane is consistently flying with its tail slightly to one side (e.g. due to a slightly crooked vertical fin or asymmetric motor thrust), the Integrator will slowly "build up" and apply a constant rudder trim to straighten the aircraft.

Tuning & Behavior

• Default: 0.
• Recommendation: Start with a very small value (e.g. 0.05 or 0.1).
• Effect: Too much integrator will cause the tail to "Wander" or hunt slowly left and right. Too little will leave the plane flying "crabbed" through the air.

Yaw Coordination Gain (Bank Angle) (YAW2SRV_RLL)

Description

YAW2SRV_RLL fine-tunes the turn geometry.

For a fixed-wing aircraft to turn efficiently, the nose must rotate (yaw) at a specific rate that matches the bank angle and airspeed. If the yaw is too slow, the plane slips into the turn. If too fast, it skids out. This parameter adjusts the calculation of that "perfect" yaw rate.

Tuning & Behavior

• Default: 1.0 (Ideal physics).
• Values > 1.0: Demands more yaw into the turn.
• Values < 1.0: Demands less yaw into the turn.
• Significance: If you have accurate airspeed calibration, leave this at 1.0. If you see persistent sideslip during steady turns, adjust YAW2SRV_SLIP first.

Sideslip Coordination Gain (YAW2SRV_SLIP)

Description

YAW2SRV_SLIP is used to achieve perfectly "Coordinated" turns (where the ball stays centered in a physical cockpit).

When an aircraft banks into a turn, it often experiences "Sideslip" – moving through the air slightly sideways. This parameter uses the accelerometer to sense that sideways force and automatically applies the correct amount of rudder to keep the nose pointed exactly where the plane is flying.

• 0: Disabled. Standard for flying wings and gliders.
• Non-Zero: Active coordination for planes with a vertical tail.

Tuning & Behavior

• Default: 0.
• Usage: Only use this for traditional aircraft with a large vertical fin/rudder and significant fuselage side area.
• Tuning Order: Tune this Last, after YAW2SRV_DAMP and YAW2SRV_INT are finalized.