What are the requirements to descend below MDA/DH?

The correct answer highlights that for a pilot to descend below the Minimum Descent Altitude (MDA) or Decision Height (DH), two conditions must be satisfied: the aircraft must be in a position to land, and the visibility must meet the required criteria set for the approach.

Being "in a position to land" means that the aircraft should be aligned with the runway, and the pilot should have sufficient control and situational awareness to complete the landing safely. This position is crucial because it ensures that the descent is performed with the necessary control and awareness of terrain and obstacles.

Ensuring that visibility meets the requirements is equally essential as it directly impacts the pilot's ability to see the runway and make a safe landing. Each approach procedure specifies visibility minimums that must not be violated for a safe landing.

The other options emphasize incorrect conditions or requirements that should not be used to justify descending below the MDA or DH, such as having flight visibility below prescribed limits, only needing the runway visible, or not considering the minimum altitude in various conditions. These conditions could pose serious safety risks during an approach and landing.