Final answer:
When a pilot experiences the "black hole" illusion on final approach, they tend to underestimate altitude and descend too rapidly.
Step-by-step explanation:
When a pilot experiences the "black hole" illusion on final approach, they tend to underestimate altitude and descend too rapidly. This illusion occurs when there are no visual cues to judge distance and the pilot's senses are affected by the lack of reference points. As a result, the pilot may perceive the aircraft to be higher than it actually is and may make a premature descent.