Engineering question: What might be the effects of compass interference ? For example, flying near a power line ? I am guessing that since the compass data is used to hold YAW angle, the YAW might be wrong, but would this be a cause of total fly away ? Wouldn't the flight controller see that the GPS data is showing position way off, and revert to something more safe, like ignoring the compass data and 'limp' home with inertial and GPS based navigation only ?