Definition
On the attitude indicator, a unit of pitch displacement equal to the thickness of one of the horizontal reference bars (the small wings) of the miniature airplane symbol. Pilots describe pitch changes in fractions or multiples of this width — for example, 'one-half bar width nose up' or 'one bar width nose down' — to communicate small, precise pitch adjustments without needing exact degrees.
Plain English
It is a way of measuring how far the airplane symbol on the attitude indicator has moved up or down compared to the artificial horizon, using the thickness of the symbol's wings as the ruler.
Context Anchor
Seen when learning to read the attitude indicator and make small pitch corrections during instrument flying.
Derivation
The 'bar' refers to the horizontal wing-like bars of the miniature airplane symbol on the face of the attitude indicator. 'Width' refers to the thickness of those bars. Together the phrase simply means 'a distance equal to the thickness of one bar' — a built-in ruler on the instrument itself.
Why Pilots Care
Provides a consistent visual reference for accurate pitch control without outside visual cues, reducing the chance of over- or under-correction in IMC.
Analogy
It is like using the width of your thumb as a quick measuring guide instead of pulling out a ruler.
Grounding Statement
The width of the bar on the instrument face represents roughly two degrees of pitch change, giving the pilot a repeatable unit for attitude adjustments.
Intuition Check
Do not read one bar width as a fixed distance in inches or a fixed number of degrees for every aircraft and instrument. Here it means a visual reference on that attitude indicator display.
Example Sentence 1
During level-off, raise the nose about one-half bar width above the horizon to stop the descent smoothly.
Example Sentence 2
In level cruise the pilot lowered the pitch attitude one bar width to correct a slight climb.