Definition
Adjustable blades inside the compressor section of a turbine engine that change their angle automatically as engine speed and operating conditions change. By rotating to different angles, they keep the airflow striking the following row of compressor blades at the correct angle, which prevents compressor stalls and maintains efficient compression across a wide range of power settings.
Plain English
Small wing-shaped guides inside the engine that swivel to keep air flowing into the compressor at the right angle, no matter how fast the engine is running.
Context Anchor
Seen in turbine engine systems discussions, especially when learning how a turbine engine controls airflow during changes in power.
Derivation
Stator comes from the Latin stare, meaning 'to stand.' Stator vanes are the stationary guide blades inside the compressor (as opposed to the rotating blades). 'Variable' here means their angle can change, even though the vanes themselves don't spin around the engine axis.
Why Pilots Care
They improve engine efficiency and safety by allowing stable compressor operation from idle to high power without aerodynamic stall.
Analogy
They are like adjustable window blinds. The slats do not spin around the room, but they tilt to guide what passes through them.
Intuition Check
Do not assume “stator” means the vanes never move at all. They do not rotate like compressor blades, but on a variable system they can tilt to change the direction of airflow.
Example Sentence 1
The variable stator vanes opened wider as the pilot advanced the throttle, keeping the airflow steady through the compressor.
Example Sentence 2
At high altitude cruise the FADEC commanded the variable stator vanes to a more closed position for better compressor efficiency.