What should pilots use in conjunction with a magnetic compass for the most accurate navigation?

Using electronic navigation systems in conjunction with a magnetic compass provides pilots with enhanced accuracy and reliability in navigation. Electronic navigation systems, such as GPS and other avionics, offer precise positioning information, course guidance, and are less susceptible to the various errors that can affect magnetic compasses, such as magnetic declination and interference from metallic objects.

The integration of these systems allows pilots to cross-reference their heading and position against the magnetic compass, leading to better situational awareness and navigation accuracy. Relying solely on a magnetic compass may not account for changes in magnetic variation or local anomalies, therefore utilizing electronic systems is crucial for precise navigation, especially in complex airspace or during poor visibility conditions.

In contrast, other choices like visual flight rules, weather reports, and ground-based navigation aids may serve specific purposes but do not directly enhance the magnetic compass's navigation capabilities in the same way electronic systems do.