Failsafes (ArduPilot)

The Failsafes page configures automatic safety actions that trigger when critical systems fail. The available failsafe options vary by vehicle type.

Battery Failsafe

Configurable per battery (if multiple batteries are present):

• Low battery action — what to do when the battery reaches low level (RTL / Land / SmartRTL / etc.)
• Critical battery action — what to do when the battery reaches critical level
• Low/Critical voltage thresholds — voltage levels that trigger each action
• Low/Critical capacity thresholds — remaining mAh levels that trigger each action

Ground Station Failsafe

• GCS failsafe enable — action when GCS heartbeat is lost
• GCS timeout — time without heartbeat before triggering (Copter/Rover)
• Trigger method — Heartbeat only / Heartbeat + RSSI / Heartbeat + AUTO mode (Plane)

Throttle Failsafe

• Throttle failsafe enable — action when RC throttle signal is lost
• Throttle failsafe value — PWM value that indicates signal loss
• Additional options vary by vehicle type (short/long action timeouts for Plane, etc.)

EKF Failsafe

• EKF failsafe action — action when the EKF position/velocity estimate becomes unreliable (Land / AltHold / Hold)
• EKF variance threshold — EKF variance level that triggers the failsafe

Other Failsafes

Depending on vehicle type, additional failsafes may include:

• Dead Reckoning (Copter) — action and timeout when GPS is lost
• Crash Check — detect and respond to crashes
• Vibration — detect excessive vibration
• Leak Detection (Submarine) — pin and logic level for leak sensors
• Internal Temperature / Pressure (Submarine) — environmental limits