Definition
A unit of weight in the U.S. customary system equal to 16 ounces, or approximately 0.4536 kilograms. In aviation, the pound is the standard unit for expressing aircraft weight, fuel quantity, payload, and thrust.
Plain English
A standard measure of how heavy something is. One pound is a little under half a kilogram. In flying, it's how we measure the weight of the aircraft, the fuel on board, the load being carried, and even the pushing force from a jet engine.
Context Anchor
Seen in aircraft loading information, weight-and-balance calculations, baggage limits, fuel weights, and engine thrust ratings.
Derivation
From the Latin 'pondus,' meaning weight. The abbreviation 'lb' comes from the Latin 'libra,' which was a Roman unit of weight. This is also why the pound symbol in older texts is 'lb.'
Why Pilots Care
All aircraft weight limits and many thrust ratings are stated in pounds; exceeding them directly reduces climb performance and safety margins.
Intuition Check
Do not treat pound as money, a place for animals, or simply a casual word for heaviness. In aviation, a pound is a measured unit, and the number matters for loading, performance, and safety.
Example Sentence 1
The aircraft's maximum takeoff weight is 2,400 pounds, including fuel, passengers, and baggage.
Example Sentence 2
This engine produces 180 pounds of thrust at full power.