Sensations
Why does turning make me feel like I am falling or dizzy?
Short answer: Your inner ear gets confused when you cannot see the horizon.
Inside your ear is fluid that senses movement. When the plane banks to turn, gravity pulls on that fluid differently. If you can't see the outside horizon to tell your brain you are just turning, your brain might guess you are falling. It is a harmless biological illusion; the altimeter shows we are flying perfectly level.