The other day, I encountered an anomaly during an otherwise normal flight. During a segment between two consecutive waypoints—one at 20 m and the next at 80 m—instead of performing the expected steady and progressive climb, the aircraft rapidly climbed to the target altitude. In addition to this, it veered considerably off-course. This deviation does not appear to have been caused by a near-stall due to the steep climb, but rather by a roll commanded by ArduPilot.
The mission included other identical waypoint transitions, one of which is included in the attached log file. All those behaved as expected. The log clearly shows that the TECS commanded the steep climb instead of a gradual one, and the attitude control commanded the roll that led to the off-course trajectory.
What I am failing to understand is why. The next climb in the mission is identical in terms of waypoint settings. There is no RC nudge input during the anomaly. So what can be the reason for this?
Log: Deleted