Definition
The physical forces a pilot's body feels when the aircraft changes speed or direction. These forces act on the inner ear and other sensory organs and can produce false sensations of climbing, descending, or turning when outside visual references are not available.
Plain English
The push and pull you feel in your body when the airplane speeds up, slows down, or changes direction. Without a clear view outside, these feelings can trick you into thinking the airplane is doing something it isn't.
Context Anchor
Seen in instrument flying and human factors discussions, especially when explaining how body position and motion sensations can affect a pilot’s judgment.
Derivation
Acceleration comes from the Latin 'accelerare,' meaning 'to hasten' or 'speed up.' In flying, it covers any change in motion -- speeding up, slowing down, or turning -- not just going faster.
Why Pilots Care
Unrecognized acceleration forces produce false sensations of pitch or bank, leading to incorrect control inputs and potential loss of control in IMC.
Analogy
It is like being pressed back into a car seat when the car speeds up, or leaning sideways when the car turns. The airplane can create similar body sensations, but in flight they can be harder to judge without looking at the instruments.
Grounding Statement
When a car accelerates from a stop, you feel pressed back into the seat. In an aircraft, that same sensation can feel exactly like the nose pitching up -- even when it isn't.
Intuition Check
Acceleration does not only mean “going faster” here. Any change in speed or direction can create acceleration forces.
Example Sentence 1
During takeoff, acceleration forces can create a false sensation that the nose is pitching up more than it actually is.
Example Sentence 2
In the turn to final, acceleration forces from the bank created a sensation of climbing, prompting the pilot to verify altitude on the altimeter rather than trusting the seat-of-the-pants feeling.