Variable stator vanes (VSV) are stationary aerodynamic blades located in the high-pressure compressor of a gas turbine engine. Their pitch angle automatically adjusts based on engine speed to optimize airflow, preventing compressor stalls at low speeds and maximizing efficiency at high thrust.
Heard on the job
The engine surge during spool-up was traced to a sticking VSV actuator.
Insider tip
Mechanics often check the VSV rigging first when an engine has a history of low-speed compressor stalls.