A compass calibration may be required if the compass check preflight step is failing. This may be due to changing payloads, where you are flying from, or a compass error.
Before starting a compass calibration, make sure that the aircraft is disarmed and that the batteries, payload, and the wing are installed in the aircraft. The payload should be powered-on. Avoid calibrating near a magnetic source such as large metal objects, vehicles, magnets, high power transmission lines, etc.
Pickup the aircraft and rotate the aircraft about each axis. As you do so the progress bar will slowly move until complete. The process typically takes less than a minute. If the aircraft observes a magnetic anomaly, or gets inconsistent data during the calibration, the calibration will automatically restart. Once a valid calibration has been obtained, the aircraft will need to be restarted before proceeding. Set the aircraft on the ground, remove the wings, and disconnect and reconnect all three batteries.
An accelerometer calibration may be required if the aircraft is refusing to arm due to an accelerometer error.
To start, go to
Settings Tab ⇨
Accelerometer Calibration and select
Start Accelerometer Calibration.
The GCS will walk you through all the required steps.
After the calibration is complete the aircraft must be restarted by disconnecting and reconnecting the batteries.