The aircraft is already outside the fence on the ground

What ArduPilot says:

• Vehicle breaching …

A fence is already crossed while the aircraft sits on the ground, so it will not arm. The message names the fence: Max Alt, Circle, Polygon or Min Alt. Circle means home is FENCE_RADIUS or more away. Polygon means the aircraft is outside an inclusion area, or inside an exclusion area, drawn in the ground station. With FENCE_AUTOENABLE 3 the drawn fence is checked before arming although the fence is still off, and then the name can be missing: “Vehicle breaching” with nothing after it means the drawn fence.

What to do, most likely first

1. The fence on the aircraft was drawn for another field, or the aircraft stands just outside its edge.

   CheckRead the fence back in the ground station and see where the aircraft is on the map relative to it.

   FixCarry the aircraft inside the area, or draw the fence for this field and write it to the aircraft.

2. Home is not where the aircraft is: it was set somewhere else and the aircraft is now farther from it than FENCE_RADIUS.

   CheckLook at the home icon on the map and the distance to it.

   FixReboot at the take-off place, or set home to the current position from the ground station.

3. The position estimate is poor or jumping, so the aircraft only appears to be outside.

   CheckWatch the aircraft's icon on the map for a minute: it should sit still, within a few metres.

   FixWait for a better GPS fix in the open, away from buildings and trees.

The fence is checked on the ground as well, precisely so that this can be shown before take-off; nothing is done about a breach while disarmed.

Parameters to look at

Where to do it:Failsafe Explainer