Definition
A pitot-static flight instrument that displays the rate at which the aircraft is climbing or descending, expressed in feet per minute. It works by measuring the rate of change of static pressure as the aircraft changes altitude. Also commonly called the vertical speed indicator (VSI).
Plain English
A cockpit gauge that shows how fast the aircraft is going up or coming down, measured in feet per minute.
Context Anchor
Seen on the instrument panel and in instrument-flying discussions, especially when icing could affect instruments that depend on outside air pressure.
Derivation
The name describes the instrument directly: it indicates the rate (speed) of climb (and descent). Straightforward operational naming, common in early aviation instrumentation.
Why Pilots Care
Helps maintain precise vertical performance and detect changes caused by icing, power loss, or configuration issues.
Analogy
It is like a speedometer for altitude change: not how fast the airplane is moving forward, but how fast its height is changing.
Intuition Check
Do not assume it only matters during a climb. Despite the name, it also shows descent; it measures rate of altitude change, not nose angle or engine power.
Example Sentence 1
After takeoff, the pilot pitched for an indicated 700 feet per minute on the rate-of-climb indicator.
Example Sentence 2
A sudden drop on the rate-of-climb indicator warned of performance loss from wing icing.