When can a pilot continue below MDA/DA if the runway environment is in sight?

The ability for a pilot to continue below Minimum Descent Altitude (MDA) or Decision Altitude (DA) is primarily based on the visibility of the runway environment. When the pilot can see the runway threshold, lights, and markings, this signifies that they have acquired the necessary visual references needed for a safe landing. The visual cues confirm that the aircraft is on a proper approach path to land, allowing the pilot to descend appropriately and complete the landing phase.

This adherence to visual references is critical for ensuring safety as it reduces the risks associated with continuing an approach without adequate visual references, which could lead to dangerous situations such as controlled flight into terrain.

The other options do not align with the regulations governing descent below MDA/DA. Clearance from the co-pilot is not required; the descent is based solely on visual confirmation. Autopilot disengagement does not confer the necessary visual references for a safe landing. Lastly, while a visual approach can lead to descending, the critical factor remains that the runway environment must be in sight before continuing below MDA/DA.