Definition
A night visual illusion in which an aircraft seen at a distance appears to be moving away from the observer when it is actually approaching, or appears to be approaching when it is actually moving away. The illusion arises because, at night, depth and motion cues are reduced and the brain can interpret the same set of lights in two opposite ways.
Plain English
At night, another aircraft can look like it's flying toward you when it's really flying away, or the other way around. Your eyes can flip between the two interpretations because there isn't enough information in the dark to be sure which is correct.
Context Anchor
Encountered during night flying when judging other aircraft by their lights, especially when there are few ground or background references.
Derivation
"Reversible" means it can switch between two states. "Perspective" refers to how the brain judges depth and direction of motion. The name describes the effect directly: the perspective you assign to a distant aircraft can reverse on you.
Why Pilots Care
Misjudged distance can cause the pilot to alter power or pitch incorrectly, leading to an unstabilized approach or landing short or long of the runway.
Analogy
Like watching a distant train at night and suddenly not being sure whether it is coming toward you or moving away until the lights change size rapidly.
Grounding Statement
With only a few lights against a dark background, your eyes may not have enough information to tell whether another aircraft is getting closer or farther away.
Intuition Check
Do not assume “reversible” means the illusion can be safely undone once you notice it. Here it means your visual interpretation can flip: coming closer may look like moving away, or moving away may look like coming closer.
Example Sentence 1
On a dark night with no horizon, the instructor pointed out how a distant aircraft's lights produced a reversible perspective illusion, briefly making it look like the traffic was heading away when it was actually closing on us.
Example Sentence 2
The pilot recognized the reversible perspective illusion and cross-checked the altimeter before adjusting power.