Definition
The airspeed at which an airplane is flown during the cruise phase of flight, selected by the pilot from the manufacturer's recommended range to balance fuel efficiency, engine wear, time en route, and passenger comfort.
Plain English
The steady speed you settle into once you've leveled off and are flying toward your destination, chosen for a good mix of fuel use and travel time.
Context Anchor
Seen in cruise-flight planning, performance charts, and in flight after the airplane has leveled off at the chosen altitude.
Derivation
"Cruise" comes from the Dutch kruisen, meaning to cross or travel back and forth. In aviation, the cruise phase is the long, steady portion of the trip between climb and descent, so cruise speed is simply the speed flown during that phase.
Why Pilots Care
The chosen cruise speed directly determines fuel burn, time enroute, engine temperature, and available reserves, all of which affect flight safety and legality.
Intuition Check
Cruise speed does not mean the airplane’s fastest possible speed. It means the selected steady speed for the main travel portion of the flight.
Example Sentence 1
After leveling off at 6,500 feet, the pilot reduced power and let the airplane settle at its planned cruise speed.
Example Sentence 2
At 8,000 feet the performance table listed a cruise speed of 105 knots that would give four hours of endurance with reserves.