Definition
The information the brain receives from the body's sensory systems — primarily vision, the vestibular system (inner ear balance organs), and proprioception (the 'seat of the pants' sense from muscles, joints, and skin) — used to determine the body's position, motion, and orientation in space.
Plain English
The signals your eyes, inner ear, and body send to your brain so it can work out which way is up, whether you are moving, and how you are oriented.
Context Anchor
Seen in instrument flying discussions about spatial disorientation, especially when outside visual references are limited or missing.
Derivation
From Latin 'sensus' (feeling, perception) and 'percipere' (to take in, to grasp). Together they describe how the body takes in information from its surroundings — useful here because the chapter is about how those incoming signals can become unreliable in flight.
Why Pilots Care
Relying on these perceptions instead of instruments in clouds or low visibility commonly leads to spatial disorientation and loss of control.
Grounding Statement
If your body says the airplane is turning but the instruments show straight-and-level flight, the instruments are the more reliable source.
Intuition Check
Do not assume sensory perceptions are the same as facts. They are body signals, and in instrument flying those signals can be misleading.
Example Sentence 1
In instrument conditions, a pilot's sensory perceptions can suggest the aircraft is level when the instruments clearly show a turn.
Example Sentence 2
Spatial disorientation training teaches pilots to recognize when sensory perceptions no longer match the actual flight path.