Definition
The phase of flight between climb and descent during which the airplane is flown at a relatively constant altitude, airspeed, and power setting to cover distance efficiently.
Plain English
The steady part of the flight, after climbing to your chosen altitude and before starting down, where the airplane is flown level at a fixed power setting to travel toward the destination.
Context Anchor
You will see this term when learning how the airplane feels in steady, normal flight and when setting power after leveling off from a climb.
Derivation
From the Dutch 'kruisen,' meaning to cross or traverse. In aviation it carries the same sense: the part of the flight spent crossing distance, rather than climbing or descending.
Why Pilots Care
Most of the flight is spent in cruise, and most fuel planning, range calculations, and performance numbers are based on cruise settings. Choosing the right cruise altitude, power, and mixture directly affects fuel burn, time en route, and how much reserve remains on arrival.
Intuition Check
Cruise flight does not mean the pilot can stop paying attention. It means the airplane is in the steady en route part of the flight.
Example Sentence 1
After leveling off at 6,500 feet, the pilot reduced power to a cruise setting and trimmed the airplane for hands-off flight.
Example Sentence 2
During cruise flight the pilot periodically scanned engine instruments while maintaining heading and altitude.