← All explained questions · Supplemental · XI — Night Operations
The most common night-flight VISUAL ILLUSION is
Choices
✓ altitude over featureless terrain (water, snow, dark countryside) appearing higher than it is, leading the pilot to descend prematurely.correct
The featureless-terrain illusion (also called a black-hole approach): featureless terrain or water at night provides no visual depth cues. Pilots tend to fly LOWER than intended — sometimes into the terrain short of the runway. The antidote is to rely on the instruments (altimeter, VSI, glideslope if available), use the VASI or PAPI, plan a steeper-than-normal approach where possible, and stay especially alert on final.
all colors appearing dimmer.
Color dimming is real (rod vs cone vision) but not the dangerous illusion.
engine noise increasing.
Engine noise is constant.
instrument lights fading.
Instrument lights have a dimmer; not an illusion.
Why
The featureless-terrain illusion (also called a black-hole approach): featureless terrain or water at night provides no visual depth cues. Pilots tend to fly LOWER than intended — sometimes into the terrain short of the runway. The antidote is to rely on the instruments (altimeter, VSI, glideslope if available), use the VASI or PAPI, plan a steeper-than-normal approach where possible, and stay especially alert on final.
FAA source: PHAK Ch 17, AIM 8-1-5; AIM 8-1-5 Illusions in Flightbrowse the reference library →
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Original study question written for this course — representative of FAA knowledge-test topics, not an actual current FAA exam question. Reviewed by a panel of three CFIs + AI review.