In-flight Visual Illusions

Type of Illusion	Explaination		Example		Reference
False Visual Reference	This happens when a pilot uses a false visual reference to orientate the aircraft, because of the confusing ground and star light. This can commonly happen at night, or when flying over banks of cloud or water.				Image taken from [Aeromedical] on 25/08/09 and (CAA, 2009[5])
Runway Slope	A runway slope can affect a pilots perception of how high they are when approaching to land.				Image taken from [Aeromedical] on 24/08/09
Ground Slope	When the ground before a runway is sloping, this can affect a pilots perception of how high they are when approaching to land.				Image taken from [Aeromedical] on 24/08/09
Runway Width	Runway width can lead a pilot to thinking they are either too high or too low if they are used to landing on another width.				Image taken from [American Flyers] 24/08/09
White-Out	White-out occurs when clouds or snow blend the sky into the ground. It is hard if not impossible to see the horizon				Image taken from [Wikipedia] 24/08/09
Blind Spots	Due to the make up of the eye, a pilot will have a blind spot in each eye. If they focus on a particular area they may miss an aircraft approaching from another area. Practice on this image, focus on the cross and move your head forwards. At a certain point the aircraft on the right will disappear.				Image taken from [AVIA 141] 24/08/09
Black Hole Effect	This occurs at night when the area surrounding a runway has no lighting or visual cues. The pilot may think the aircraft is at a higher apprach and will tend to fly a lower than normal approach, causing the undershoot on landing.				Image taken from [Orbiter] 24/08/09 and (CAA, 2009[5])
Autokinesis	When looking at a fixed, single light source against a totally dark background, such as a star, the pilot may wrongly think the light is moving towards himself/herself and he/she is going to crash with another plane.				(CAA, 2009[5])

References

1. Aeromedical : Aeromedical Spatial orientation and disorientation during flight: Illusions during the approach and landing. Retrieved from the World Wide Web: http://aeromedical.org/Articles/graphics/a&l3.jpg 24 August 2009

2. Wikipedia : Wikipedia White Out Retrieved from the World Wide Web: http://en.wikipedia.org/wiki/Whiteout_(weather) 24 August 2009

3. Orbiter : Orbiter Orbiter Updates Retrieved from the World Wide Web: http://www.gule.it/Orbiter/ 24 August 2009

4. American Flyers : American Flyers Pilots Handbook Retrieved from the World Wide Web http://www.americanflyers.net/aviationlibrary/pilots_handbook/chapter_15.htm 24 August 2009

5. Civil Aviation Authority of New Zealand. (2009). Night VFR. New Zealand: New Zealand Government.

Want to know more?

Wikipedia - Optical Illusions

General Information about visual illusions

Wikipedia - Sensory Illusions

Information relating specifically to all types of illusions present in aviation.

---

Contributors to this page

Authors / Editors

R_Pattenden
wsy

Proof-readers