QSTABILIZE Mode

QSTABILIZE mode allows you to fly your vehicle manually, but self-levels the roll and pitch axis.

Tip

If you’re learning to fly, try QHOVER or QLOITER instead of QSTABILIZE. You’ll have fewer crashes if you don’t need to concentrate on too many controls at once.

Warning

While QSTABILIZE mode does not necessarily require GPS, switching to QRTL or RTL in case of emergency does. Make sure you do have a reliable position estimate prior to arming, most commonly provided by 3D GPS fix with sufficient HDOP. This is required by default in the arming checks. It is highly recommended that these checks not be disabled.

Warning

Flying Quadplane backwards at speed or backwards into high wind is not recommended, since the Plane control surfaces will act backwards and could increase instability.

Overview

  • Pilot’s roll and pitch input control the lean angle of the QuadPlane. When the pilot releases the roll and pitch sticks the vehicle automatically levels itself.
  • Pilot will need to regularly input roll and pitch commands to keep the vehicle in place as it is pushed around by the wind.
  • Pilot’s yaw input controls the rate of change of the heading. When the pilot releases the yaw stick the vehicle will maintain it’s current heading.
  • Pilot’s throttle input controls the average motor speed meaning that constant adjustment of the throttle is required to maintain altitude. If the pilot puts the throttle completely down the motors will go to their minimum rate (Q_M_SPIN_ARMED) and if the vehicle is flying it will lose attitude control and tumble.
  • The throttle sent to the motors is automatically adjusted based on the tilt angle of the vehicle (i.e. increased as the vehicle tilts over more) to reduce the compensation the pilot must do as the vehicle’s attitude changes.

Note

Always switch into a manual mode such as QSTABILIZE if the autopilot fails to control the vehicle. Maintaining control of your copter is your responsibility.

Common Problems

  • QuadPlane flips immediately upon take-off. This is usually caused by the motor order being incorrect or spinning in the wrong direction or using an incorrect propeller (clockwise vs counter-clockwise). Check the rc connections for your autopilot.
  • QuadPlane wobbles on roll or pitch axis. This usually means the Rate P values are incorrect. See Copter Tuning section for some hints as to how to adjust the Q_A_xxx parameters.
  • QuadPlane wobbles when descending quickly. This is caused by the copter falling through it’s own props wash and is nearly impossible to tune out although raising the Rate Roll/Pitch P values may help.
  • QuadPlane yaw right or left 15degrees on take-off. Some motors may not be straight or the escs need calibration QuadPlane ESC Calibration.
  • QuadPlane does not maintain altitude or does not stay perfectly still in the air. As mentioned above this is a manual flight mode and requires constant control of the sticks to maintain altitude and position.
  • occasional twitches in roll or pitch. Normally caused by some kind of interference on the receiver (for example FPV equipment placed too close to the receiver) or by ESC problems that may be resolved by QuadPlane ESC Calibration.
  • sudden flips during flight. This is nearly always caused by mechanical failures of the motor or ESCs.

Hover Throttle

Usually, it is desired to hover in any mode at mid-stick on throttle, so that transitions between modes is easily accomplished without throttle position changes. This can be adjusted using the Q_M_THST_HOVER parameter, or automatically learned in QHOVER or QLOITER modes by enabling Q_M_HOVER_LEARN.

Note

If Q_THROTTLE_EXPO = 0 in QACRO and QSTABILIZE modes, then Q_M_THST_HOVER, whether set manually or learned via Q_M_HOVER_LEARN , is not applied, and the throttle is determined directly from the RC input.