Under CASR Part 101, can we operate an RPAS through fog if we have obstacle voidance sensors and area approval?

Operating a Remotely Piloted Aircraft System (RPAS) in fog conditions is inherently risky due to significantly reduced visibility. Under CASR Part 101, safety is paramount, and operating any aircraft, including an RPAS, requires a clear line of sight. If the fog is dense enough to impair visibility to a point where the remote pilot cannot ascertain the aircraft's position, orientation, or maintain adequate situational awareness, this poses severe safety risks.

While obstacle avoidance sensors can provide some level of automated hazard detection, they do not replace the need for the pilot to maintain visual line-of-sight with the aircraft. Furthermore, area approval does not override the fundamental requirement of maintaining visibility. Thus, even with technological aids, flying an RPAS in fog conditions without the ability to see it clearly and continuously is not compliant with safety regulations outlined in CASR Part 101.

Therefore, the correct response reflects the principle that safety must not only be assumed based on technological advancements but must also align with regulatory standards and visual control requirements.