Definition
The rate of climb or descent shown on the vertical speed indicator (VSI), expressed in feet per minute. It is derived from the rate at which static pressure changes inside the instrument as the airplane changes altitude, and reflects what the instrument is currently displaying rather than a directly measured airspeed.
Plain English
How fast the airplane is going up or down right now, according to the VSI on the panel, measured in feet per minute.
Context Anchor
Seen on the vertical speed indicator and in cockpit instrument indications, especially when comparing normal readings with possible system malfunction indications.
Derivation
"Indicated" means "as shown by the instrument," not necessarily the true or actual value. So Indicated Vertical Speed is the climb or descent rate the instrument is showing, which may differ from reality if the static system is blocked or lagging.
Why Pilots Care
Allows pilots to maintain precise climb or descent rates and detect instrument or system problems early.
Analogy
It is like a car speedometer for up-and-down motion. It shows the rate the instrument senses, but the pilot still checks whether that reading makes sense with the rest of what is happening.
Intuition Check
Indicated does not mean guaranteed exact; it means shown by the instrument. Vertical speed is the airplane's up-or-down rate, not its forward speed.
Example Sentence 1
After leveling off, the pilot waited for the indicated vertical speed to settle back to zero before trimming for cruise.
Example Sentence 2
After the static system malfunction, the indicated vertical speed became unreliable and lagged behind actual performance.