Definition
The vertical speed at which an airplane is losing altitude, expressed in feet per minute (fpm) and shown on the vertical speed indicator (VSI). Descent rate is controlled primarily through pitch and power adjustments and is selected to suit the phase of flight, terrain, traffic, and passenger comfort.
Plain English
How fast the airplane is going down, measured in feet per minute. A 500 fpm descent rate means the airplane is losing 500 feet of altitude every minute.
Context Anchor
Seen during descents, approach planning, and any time a pilot is watching how quickly the airplane is moving downward.
Derivation
Descent comes from a Latin word meaning “to climb down.” Rate means a measured amount of change over time. Together, descent rate means the measured speed of going downward.
Why Pilots Care
Proper descent rate keeps the aircraft on the correct vertical path, prevents unstable approaches, and avoids excessive sink rates that can lead to hard landings or terrain conflicts.
Intuition Check
Do not confuse descent rate with how steep the airplane’s path looks. Descent rate is about how fast altitude is being lost over time, not just the angle of the flight path.
Example Sentence 1
The instructor asked the student to establish a 500-foot-per-minute descent rate while maintaining 90 knots.
Example Sentence 2
A descent rate that exceeds 1,000 feet per minute close to the ground can make the approach unstable.