V1.0.0
Dec 31, 2023

Scenario: 
- Predetermined flight volume
- No uninvolved persons on site (indoor is allowed)
- Airspace is controlled
- Adjacent airspace is controlled or adjacent ground area is populated

Cat. 1. Automatic RTH, no damage.

- RC radio failure
- Telemetry radio failure
- Battery low
- Operator breaches fence

Cat. 2. Automatic Land, optional operator takeover to prevent damage within flight volume

- Battery critical
- Compass failure, detected by Ardupilot
- GNSS failure, detected by Ardupilot
- Battery low during RTH

Cat. 3. Operator intervention in Stab required to prevent breaching flight volume

- Compass failure, not detected by Ardupilot (e.g. toilet bowling)
- GNSS failure, not detected by Ardupilot
- Other position control failure

Cat. 4. No operator intervention possible, damage likely, within flight volume. 

- Battery or power failure
- Airframe failure
- Collision
- Thrust system failure (prop, motor, inverter) 
- Flight controller complete flight failure, pilot cannot keep vehicle in the air for whatever reason.
- (can be disregarded for civillian applications) Complete EM blackout: inertial Land within volume (dependant on size of risk buffer, wind speed and vehicle characteristics).

Cat 5. FTS needed to ensure containment

- While RC link lost, a Cat. 3 failure occurs and the vehicle is about to leave the flight volume.