Autokinesis and False Horizons
Autokinesis
Staring at a single point of light against a dark background for more than a few seconds illustrates the illusion. After a few moments, the light appears to move on its own. To prevent this illusion, focus the eyes on objects at varying distances and avoid fixating on one target. Be sure to maintain a normal scan pattern. The illusion imitates the movement of light that may cause disorientation.
The Cessna Skylane has a nearly complete wrap-around windshield. If you follow a traveled road, with little lighting in the surrounding area at night, you will experience autokinesis. When you check the rear windows, of a Cessna, a string of dim lights that appear,in your vision, curves around towards the tail. It creates a sensation of turning to the left if the road, with car lights, is on your right. Vice-versa if the road is on your left.
Autokinesis, with just one spot of light moving, may induce a similar illusion.
The illusion is so powerful you need to concentrate on your instruments to recover adequately.
False Horizon
A false horizon can occur when the natural horizon is obscured or not readily apparent. Bright stars and city lights generate the false horizon. It can also occur while flying toward the shore of an ocean or a large lake. Because of the relative darkness of the water, the lights along the shoreline can be mistaken for stars in the sky.
You may think your in a relatively steep climb and you counter this by pushing forward on the yoke. It may cause a crash before you discover the illusion.
Knowing what to expect, if conditions deteriorate en-route, can save your life.
Autokinesis
Staring at a single point of light against a dark background for more than a few seconds illustrates the illusion. After a few moments, the light appears to move on its own. To prevent this illusion, focus the eyes on objects at varying distances and avoid fixating on one target. Be sure to maintain a normal scan pattern. The illusion imitates the movement of light that may cause disorientation.
The Cessna Skylane has a nearly complete wrap-around windshield. If you follow a traveled road, with little lighting in the surrounding area at night, you will experience autokinesis. When you check the rear windows, of a Cessna, a string of dim lights that appear,in your vision, curves around towards the tail. It creates a sensation of turning to the left if the road, with car lights, is on your right. Vice-versa if the road is on your left.
Autokinesis, with just one spot of light moving, may induce a similar illusion.
The illusion is so powerful you need to concentrate on your instruments to recover adequately.
False Horizon
A false horizon can occur when the natural horizon is obscured or not readily apparent. Bright stars and city lights generate the false horizon. It can also occur while flying toward the shore of an ocean or a large lake. Because of the relative darkness of the water, the lights along the shoreline can be mistaken for stars in the sky.
You may think your in a relatively steep climb and you counter this by pushing forward on the yoke. It may cause a crash before you discover the illusion.
Knowing what to expect, if conditions deteriorate en-route, can save your life.
