8.1 | Good airmanship
8.2 | Go / No-Go Decision
8.3 | Visual Line of Sight
8.4 | Distance from non-involved persons
8.5 | Other air traffic
8.6 | Height limits
8.7 | Flying with an observer
8.8 | Flying over people and buildings
8.9 | Distance criteria
8.10 | Responsibility
The maximum allowable altitude of an unmanned aircraft in the Open category is 120 meters (400 ft) above ground level (AGL). Figure 33 shows how the altitude changes in relation to the ground. It is possible that countries at national level define a geographical zone where a lower maximum altitude applies. It goes without saying that pilots must adhere to this and call in an observer if necessary.