Definition
A unit of mechanical power equal to the work done when a force of one pound moves an object a distance of one foot in one second. Power combines force, distance, and time into a single rate measurement. By definition, 550 foot-pounds per second equals one horsepower.
Plain English
It is a way to measure how fast work is being done. If you lift a one-pound weight one foot off the ground in one second, that is one foot-pound per second of power.
Context Anchor
Seen in basic aircraft performance discussions when the handbook explains work, power, and engine power units.
Derivation
The unit names its three parts directly: 'foot' (distance), 'pound' (force), and 'per second' (rate). It says exactly what it measures — how many foot-pounds of work happen each second.
Why Pilots Care
This unit lets pilots compare the actual power an engine produces to the power needed for climb, acceleration, and sustained flight.
Analogy
If you lifted a one-pound object straight up one foot every second, you would be working at one foot-pound per second.
Grounding Statement
It measures the speed of work — the same job done faster requires more foot-pounds per second.
Intuition Check
A foot-pound per second is not a weight and not a distance by itself. The words together describe a rate of doing work.
Example Sentence 1
One horsepower is defined as 550 foot-pounds per second of work.
Example Sentence 2
Divide total foot-pounds per second by 550 to convert the value into horsepower.