Definition
A biological system that detects information about the body's position, motion, and surroundings, and sends that information to the brain for interpretation. In flight, the three sensory systems pilots rely on for spatial orientation are the visual system (eyes), the vestibular system (inner ear, sensing motion and balance), and the somatosensory system (nerves in the skin, muscles, and joints, sometimes called 'seat of the pants' sensing).
Plain English
The body's way of figuring out where it is and how it is moving. Pilots use three of these systems together: their eyes, their inner ear, and the feel of pressure and movement through their body.
Context Anchor
Used in instrument flying discussions about spatial orientation, disorientation, and why pilots must rely on flight instruments when outside visual references are poor.
Derivation
From the Latin sensus, meaning 'feeling' or 'perception,' combined with system, meaning a set of parts working together. So a sensory system is a set of body parts working together to perceive the world.
Why Pilots Care
Recognizing how the sensory system can provide misleading cues in instrument conditions helps pilots avoid spatial disorientation and maintain control.
Analogy
Your senses are like onboard reporters sending messages to your brain. In instrument conditions, some of those reporters can be fooled, so the aircraft instruments become the more reliable source.
Grounding Statement
If you cannot see a clear horizon, your body may feel that the airplane is turning, climbing, or level when the instruments show something different.
Intuition Check
Do not assume a sensory system always tells the truth. In instrument flying, the key point is that body sensations can feel convincing and still be wrong.
Example Sentence 1
When a pilot enters cloud, the visual sensory system loses its outside reference, and the inner ear can begin to send misleading signals.
Example Sentence 2
Training teaches pilots to disregard unreliable sensory system inputs during instrument approaches.