Definition
A cockpit instrument that displays the rate at which the airplane is climbing or descending, expressed in feet per minute. It senses changes in static air pressure as altitude changes and translates those changes into a vertical speed reading. The VVI is also commonly called the vertical speed indicator (VSI).
Plain English
A gauge that tells the pilot how fast the airplane is going up or going down, measured in feet per minute.
Context Anchor
Seen on the instrument panel during climbs, descents, and altitude corrections.
Derivation
Vertical means up-and-down. Velocity means speed. So vertical velocity indicator literally means an instrument that shows up-and-down speed. Including 'velocity' rather than just 'speed' emphasises that direction matters here — climbing is positive, descending is negative.
Why Pilots Care
Enables precise control of vertical speed to meet assigned altitudes, avoid terrain, and maintain separation from other traffic.
Intuition Check
Do not read VVI as an altitude instrument. It shows the rate of going up or down, not the airplane’s height.
Example Sentence 1
Passing through 2,000 feet, the pilot checked the VVI and saw a steady 500 feet per minute climb.
Example Sentence 2
On final approach the VVI showed a steady 700-foot-per-minute descent while airspeed remained constant.