When can you descend below the localizer minima on an ILS approach?

The correct choice emphasizes the importance of visual references when approaching the runway on an Instrument Landing System (ILS) approach. According to standard operating procedures, pilots must maintain visual contact with the runway when descending below the localizer minima. This ensures that the pilot can visually confirm the safe operation of the aircraft and the aircraft's alignment with the runway.

Localizer minima are specified for precision approaches to define the lowest altitude to which an aircraft can safely descend while relying on instrument guidance alone. Once the pilot has visual contact with the runway environment, they can safely continue their descent and landing, as they can now visually verify their position and minimize the risk of spatial disorientation or navigational errors.

While the other choices present conditions under which a pilot might feel justified in descending, they do not adhere to the fundamental principle of aviation safety that requires visual confirmation before descending below the localizer minima. This underscores the crucial role that visual reference plays in ensuring a safe landing.