The throttle stick is too high to arm

What ArduPilot says:

• PreArm: … too high

In modes where the stick sets the motors directly (Stabilize, Acro) and in Drift, the throttle must be at zero to arm. In the other modes it must not ask for a climb: at or below the middle of the stick. Arming from the ground station in Guided or Auto skips this check.

What to do, most likely first

1. The throttle stick is not fully down.

   FixPull the throttle all the way down and arm again.

2. The calibrated minimum is lower than what the stick really gives at the bottom, so the bottom is not zero.

   CheckWith the stick down, the throttle bar in the Radio Calibration screen should read RC3_MIN, give or take RC3_DZ.

   FixCalibrate the radio again.

3. The throttle stick is spring-centred (it rests in the middle), and ArduPilot has not been told.

   CheckPILOT_THR_BHV bit 0 (feedback from mid stick) tells ArduPilot that the middle is the resting place.

   FixSet PILOT_THR_BHV bit 0 and arm in a mode that holds height (AltHold, Loiter); Stabilize with a centred throttle would spin the motors at half power.

Parameters to look at

Where to do it:Setup & Tuning Guide