Nerves in the body's skin, muscles, and joints send signals to the brain, which, along with other sensory organs, signals the body's position
These tactile signals tell the pilot his or her current position
The pilot feels acceleration when pushed back into the seat
Often termed "flying by the seat of your pants"
Forces created in turns can lead to false sensations of the true direction of gravity and may give the pilot a false sense of which way is up
Uncoordinated turns, especially climbing turns, send misleading signals to the brain
Skids and slips give the sensation of banking or tilting
Turbulence can create motions that confuse the brain as well
Pilots need to be aware that fatigue or illness can exacerbate these sensations and ultimately lead to subtle incapacitation
Postural Considerations:
The postural system sends signals from the skin, joints, and muscles for the brain to interpret relative to the Earth's gravitational pull [Figure 1]
These signals determine posture
Inputs from each movement update the body's position to the brain constantly
Again, "seat of the pants" flying is largely dependent upon these signals
These sensations, used in conjunction with visual and vestibular clues, can be fairly reliable
However, because of the forces acting upon the body in certain flight situations, many false sensations can occur due to acceleration forces overpowering gravity
These situations include uncoordinated turns, climbing turns, and turbulence
Instrument Flying Handbook, Sensations From Centrifugal Force
