The optical flow calibration ran out of time

The in-flight calibration of the optical flow sensor's scale did not collect enough samples within 120 s and gave up; the scaling is unchanged. A sample is taken only while the aircraft rolls or pitches faster than 20° per second, the sensor sees the ground move at least as fast, and the yaw rate stays under 20° per second. The lines “FlowCal: x:40% y:15%” show how full each axis was.

What to do, most likely first

1. The aircraft was not rocked enough: gentle or slow stick movements give no samples.

   CheckOne axis stays at a low percentage in the “FlowCal:” progress lines.

   FixStart the calibration again and rock the aircraft briskly in roll and in pitch, without yawing, until both percentages reach 100.

2. The sensor does not see the ground well: too high, too dark, or a surface without texture.

   CheckOF.Qual in the log is low while the aircraft is rocked.

   FixCalibrate a few metres up over well-lit ground with a visible pattern, such as grass or gravel.

Parameters to look at