During a night approach to a remote aerodrome, a black hole illusion may cause which type of approach?

• A. a normal approach
• B. a high approach
• C. a low approach
• D. the pilot losing sight of the runway

Answer: (C)

The concept being tested is how night-time visual illusions over a dark, featureless area can distort height perception and lead to a low approach. In the black hole illusion, there’s little horizon reference or ground features to judge altitude, so the pilot tends to underestimate how high they actually are. To regain what the brain thinks is level flight, the aircraft is descended more than intended, producing an approach that’s lower than the proper glide path. The effect isn’t simply about losing sight of the runway, though that can compound the challenge; it’s about misperceiving height and climbing or maintaining the correct path becomes difficult. To counter it, rely on instruments and approach procedures, hold altitude until the runway is in sight and aligned, and cross-check with the glide slope and altimeter to ensure you don’t descend below the proper path.