Pitch Compensation in Roll (PTCH2SRV_RLL)

Description

PTCH2SRV_RLL is an "Elevator-to-Aileron" mix.

When a fixed-wing plane banks (rolls) into a turn, it loses vertical lift. To maintain its altitude while turning, it must pull slightly back on the elevator. This parameter automates that process.

• 1.0 (Default): Standard compensation.
• Higher Value: Adds more back-elevator during turns (useful for "draggy" or low-lift planes).
• 0: No compensation (the plane will lose altitude in every turn unless the pilot manually pulls back).

Pitch Max Rate Down (PTCH2SRV_RMAX_DN)

Description

PTCH2SRV_RMAX_DN limits how fast the autopilot is allowed to push the nose down.

This is used to prevent aggressive "nose dives" that could lead to over-speed conditions or excessive negative G-loads.

Pitch Max Rate Up (PTCH2SRV_RMAX_UP)

Description

PTCH2SRV_RMAX_UP limits how fast the autopilot is allowed to pull the nose up.

This is an important safety limit to prevent the drone from performing a maneuver so aggressive that it stalls or exceeds the structural limits of the airframe.

• 0: Disabled (No limit).
• Value: Rate in degrees per second.

Pitch Controller Time Constant (PTCH2SRV_TCONST)

Description

PTCH2SRV_TCONST defines the "Crispness" of the pitch response for fixed-wing aircraft.

It represents the time constant of the commanded pitch. A lower value makes the plane pitch up or down more aggressively to reach its target, while a higher value makes the movement smoother and more gradual.

Tuning & Behavior

• Default: 0.5 seconds.
• Recommendation: Most models fly well with 0.5. For high-performance racing planes, you can reduce this toward 0.4. For large, heavy drones, you may need to increase it toward 0.7 or 1.0.
• Note: If set too low, the plane may oscillate or "hunt" for the target pitch angle.