Daytime Black Holes

demonstrating how the black-hole approach effect works in daytime conditions."

Glenn Grubb

Friday, September 22, 2017 at 12:00 AM ET

Verified

Key Takeaways:

Optical illusions, particularly the "black-hole illusion," are a significant aviation safety hazard, distorting a pilot's perception of distance and glideslope during landing approaches.
While commonly associated with night flying over unlit terrain, this illusion can also occur during daylight, specifically when approaching upslope runways or those elevated above surrounding terrain.
The illusion stems from the brain's misinterpretation of the runway's visual angle, leading pilots to unconsciously fly a dangerously shallow or "drooping" approach, requiring a deep understanding of these perceptual errors and environmental factors to ensure a stabilized and safe landing.

See a mistake? Contact us.

Optical illusions are all around us. A classic example might be when looking through a camera and a slow-turning airplane propeller or the wheel spokes on a car appear to slow and then reverse direction. None of that happens, of course; part what we “see” is determined by how well our eyes and brain work and play together. The bad news is there are many other optical illusions, and they can actually be quite dangerous if encountered while flying. The good news is we can understand them, anticipate them, then compensate for them.