Safety is an important element for a remote pilot to consider prior to operating an unmanned aircraft system. To prevent the unwanted movement of a UA, what action should a remote pilot take if the UA unexpectedly enters an autonomous or semi-autonomous flight mode?

Why →The remote PIC must maintain control of the aircraft at all times under § 107.19. If the aircraft enters an unexpected autonomous mode, the pilot should attempt to regain manual control immediately. If that is not possible and the aircraft poses a hazard, the flight should be terminated safely.

The trap →Allowing the autonomous mode to complete does not satisfy the control obligation: an unexpected mode activation is a malfunction, not a plan. And RTH might route the aircraft over unsafe areas depending on the home point.

Field note →Know your aircraft's control hierarchy: which stick input overrides autonomous modes, and what the emergency stop procedure is. Test these before relying on them in the field.