Definition
A sensitive rate-of-climb and descent indicator used primarily in gliders and sailplanes. It shows very small changes in vertical speed, allowing the pilot to detect rising or sinking air masses.
Plain English
An instrument that shows whether the aircraft is going up or down, and how fast, with enough sensitivity to detect even gentle lifting or sinking air.
Context Anchor
Commonly seen in glider cockpits, where the pilot needs to find rising air and avoid sinking air.
Derivation
From Latin 'varius' (changing) and Greek 'metron' (measure) — literally 'measurer of change.' The name reflects its job: measuring small changes in vertical motion.
Why Pilots Care
Enables precise control of vertical speed to meet ATC clearances, maintain performance, and ensure safe separation from terrain or traffic.
Example Sentence 1
When the variometer needle swung upward, the glider pilot circled to stay in the thermal.
Example Sentence 2
On final approach the variometer confirmed a 500 feet per minute descent rate.