Which requirements relate to Visual Flight Rules in aviation?

Visual Flight Rules (VFR) are a set of regulations under which a pilot operates an aircraft in weather conditions generally clear enough to allow pilots to see where the aircraft is going. The primary requirement of VFR is that pilots must maintain visual contact with the ground and other aircraft, which is critical for navigation and obstacle avoidance.

Maintaining pilot visibility ensures that the operator can see and avoid other aircraft and obstacles, adhere to the intended flight path, and make informed decisions based on their surroundings. This requirement is essential for safe operation during VFR flights, as it directly impacts the pilot's ability to navigate and react to any changes in the environment.

The other options, while relevant to various aspects of aviation, do not specifically address the fundamental requirements of Visual Flight Rules. Autopilot systems and navigational autonomy pertain more to instrument flight procedures than to requirements for pilot visibility and situational awareness. Similarly, promoting radio communication, while important for overall safety and coordination in aviation, does not directly relate to the fundamental need for a pilot to maintain visual line of sight during operations performed under VFR.