Definition
The engine power setting used during the en route, level-flight portion of a flight, typically established after climb is complete and selected to produce a steady airspeed at a chosen percentage of maximum continuous power (commonly 55–75%) as recommended by the aircraft's Pilot's Operating Handbook.
Plain English
The throttle setting a pilot uses for normal level flight between climb and descent — not full power, not low power, but a steady middle setting that keeps the airplane moving along efficiently.
Context Anchor
You will see this term during maneuver setup, especially when an exercise begins from normal straight-and-level flight before slowing the airplane.
Derivation
Cruise comes from older words meaning to travel or cross over an area. In aviation, it points to the steady travel part of a flight. Power refers to the work produced by the engine, so cruise power means the engine output used for steady travel.
Why Pilots Care
Correct cruise power gives the best fuel economy, protects engine life, and produces the performance numbers used for range and endurance planning.
Analogy
Like easing a car back to a steady 65 mph on the highway instead of keeping your foot on the accelerator or letting it idle.
Intuition Check
Cruise power does not mean maximum power, and it is not one fixed setting for every airplane. It means the normal power setting for steady cruise in that airplane under the current conditions.
Example Sentence 1
After leveling off at 4,500 feet, the pilot reduced the throttle to cruise power and trimmed the airplane for hands-off flight.
Example Sentence 2
The pilot cross-checked the power setting against the cruise power chart before entering the long cross-country leg.