Definition
A unit of torque or moment equal to a force of one pound applied at a perpendicular distance of one inch from a pivot point. In aircraft weight and balance, pound-inches express a moment: weight (in pounds) multiplied by arm (in inches from the reference datum).
Plain English
It is a way of measuring the turning effect that a weight has when it sits a certain distance from a fixed reference point. You get the number by multiplying how heavy something is, in pounds, by how far it sits from that reference, in inches.
Context Anchor
Seen in aircraft weight-and-balance work, especially when calculating moments for passengers, baggage, fuel, or equipment.
Derivation
The name simply pairs the unit of force (pound) with the unit of distance (inch). The hyphen shows the two are multiplied together, not divided. This mirrors how moment is defined in physics: force times distance.
Why Pilots Care
Mechanics and pilots use pound-inches to confirm correct tightening of propeller bolts and to calculate control-surface hinge moments that affect stick forces.
Analogy
Think of a child on a seesaw. The farther the child sits from the center, the more tipping effect the same weight has; pound-inches measure that weight-and-distance effect for an airplane.
Intuition Check
Do not read pound-inches as pounds plus inches. It means pounds multiplied by inches: weight times distance from the reference point.
Example Sentence 1
After adding a 50-pound bag in the rear baggage compartment with an arm of 95 inches, the pilot recorded 4,750 pound-inches in the moment column.
Example Sentence 2
The elevator hinge moment was calculated at 850 pound-inches during the preflight weight-and-balance check.