Definition
The turning effect produced by a force acting at a distance from a pivot point, calculated as force multiplied by the perpendicular distance (arm) from that point. In aircraft weight and balance, moment is the product of an item's weight and its arm, expressed in pound-inches.
Plain English
A measure of how much something tries to twist or tip the airplane around a reference point. The heavier the item and the farther it sits from that point, the bigger the moment.
Context Anchor
Seen in weight-and-balance calculations before flight, especially when adding passengers, fuel, baggage, or equipment.
Derivation
From the Latin 'momentum,' meaning movement or moving power. In mechanics, the word kept the sense of a force's power to cause rotation, which is exactly what it describes in aircraft loading.
Why Pilots Care
Keeps the center of gravity inside safe limits so the airplane remains stable and controllable.
Analogy
Think of a seesaw. A small child far from the center can balance a larger adult sitting close to the center. The 'moment' is what makes that work -- weight times distance from the pivot.
Intuition Check
Do not read moment as “a short amount of time.” In weight and balance, moment means the balancing or tipping effect of weight at a distance.
Example Sentence 1
After loading the baggage compartment, the pilot multiplied each item's weight by its arm to find its moment, then added all the moments to check the center of gravity.
Example Sentence 2
Fuel burned from the wing tanks reduced the total moment and moved the center of gravity slightly aft.