Definition
The rate at which an aircraft engine performs work, typically expressed in horsepower for piston engines or as a percentage of rated thrust for turbine engines. It is the energy output the engine delivers to turn the propeller or produce thrust, and it is controlled primarily by the throttle and, where applicable, the mixture and propeller controls.
Plain English
How much usable energy the engine is producing at a given moment to drive the aircraft forward. More power means the engine is working harder and producing more thrust through the propeller or jet exhaust.
Context Anchor
Seen in performance, takeoff, climb, cruise, and thrust discussions.
Derivation
Engine comes from older words meaning an inborn ability or device. Power comes from a word meaning ability or capacity. In aviation, the useful idea is capacity: how much work the engine can produce for moving the aircraft.
Why Pilots Care
Engine power sets the upper limit on available thrust, directly affecting takeoff distance, climb rate, and cruise performance.
Analogy
Engine power is like how hard a cyclist can push the pedals. The harder the cyclist can work, the more motion can be produced through the wheels.
Intuition Check
Do not read engine power as the same thing as thrust. Engine power is what the engine produces; thrust is the forward push that moves the aircraft.
Example Sentence 1
On takeoff, the pilot advanced the throttle smoothly to full engine power and verified the engine instruments were in the green.
Example Sentence 2
During cruise, engine power was reduced to maintain the desired airspeed and fuel flow.