Definition
A fixed numerical value that does not change within a given equation, formula, or calculation. Unlike a variable, which can take on different values, a constant remains the same every time the formula is used.
Plain English
A number that stays the same. In a formula, it's the part that never changes, no matter what other numbers you plug in.
Context Anchor
Seen in aircraft maintenance calculations, such as weight, balance, electrical, and structural formulas that use a fixed number.
Derivation
From the Latin 'constans,' meaning 'standing firm' or 'unchanging.' That captures the idea exactly: a constant holds its value while everything else around it may change.
Why Pilots Care
Many aviation formulas rely on fixed constants (such as the value of pi, or a standard conversion factor). Recognizing which numbers are constants and which are variables helps you apply formulas correctly without second-guessing the math.
Intuition Check
Constant does not mean “frequent” or “happening all the time” here. In a math context, it means fixed and unchanged during the calculation.
Example Sentence 1
When calculating the circumference of a propeller's circular path, pi is used as a constant.
Example Sentence 2
In propeller blade stress formulas, the radius from the hub to the tip section is entered as a constant.