VISUAL ILLUSIONS Flashcards
What are the visual illusions?
FFSHAVSCC
For F*cks Sake, HAVe Some Class Carl
Fascination/Fixation
False Horizon
Size/Distance Illusion
Height/Depth Perception Illusion
Autokinesis
Vection (Inducted Motion Illusion)
Structural Illusion
Confusion with Ground Lights
Crater Illusion
Describe Fascination/Fixation
Fascination: Task Saturation (in cockpit) - so engrossed with a problem or task within the cockpit, they fail to scan outside
Fixation: Target Fixation (out of cockpit) - fixating on object outside the cockpit you fail to scan / crosscheck
Solution: refrain from staring; scan
Describe False Horizon.
Aviator confuses cloud formations with the horizon or the ground, thus they may fly the aircraft in a banked attitude.
Solution: Scan instruments and other visual cues
Describe the Size/Distance Illusion.
Crewmember misinterprets an object of unfamiliar size and shape by comparing it with what they are accustomed to seeing based on experience. There are 3 types.
Describe the 3 types of Size/Distance Illusion.
1) Size Constancy Illusion – an example is landing at an unfamiliar runway. A narrower runway may lead a pilot to believe he/she is higher and further away.
2) Shape Constancy Illusion – Commonly encountered with sloping runways. An upsloping runway may give the pilot the illusion of being too high
3) Aerial Perspective Illusion – visual cues are of a different size or perspicuity (clarity and discrimination) than expected. An example is mistaking short immature trees for full grown ones. Also, objects within a hazy environment are often thought to be further away than they actual area.
Describe the Height/Depth Perception Illusion.
The height - depth perception illusion is due to a lack of sufficient visual cues and causes an aircrew to lose depth perception (i.e. flying over desert, snow, water the aviator may fly extremely low due to lack of cues.)
Solution: trust instruments and scan horizon
Describe Autokinesis.
Primarily occurs at night when ambient visual cues are minimal and a small dim light is seen against a dark background. Aviator visually fixates on light for 6-12 seconds, the light appears to move up to 20 degrees in any direction and continues to “move”.
Solution: avoid fixating on objects, develop a good scan.
Describe Vection (Induced Motion Illusion).
Falsely perceived self-motion (at a stop light, car next to you starts moving and you think you’re moving).
Solution: proper scanning - experience / knowledge of the occurrence
Describe the Structural Illusion.
Caused by effects of heat waves, rain, snow, sleet, or the shape of the windscreen - objects may appear obscure / not their true shape/size.
Solution: experience / knowledge.
Describe Confusion with Ground Lights.
Aviator mistakes ground lights for stars - which prompts aviator to place the aircraft in an unusual attitude to keep the misperceived ground lights above them.
Solution: conduct a proper scan, aided and unaided.
Describe the Crater Illusion.
Landing at night, under NVG conditions, the IR searchlight is too far under the nose of the aircraft - it will cause the illusion of landing with up-sloping terrain in all directions (a crater).
Solution: proper use of landing and search light and scanning.
