US Patent 10358934 Method and apparatus for adjusting variable vanes

According to one aspect of the present disclosure, a gas turbine engine is disclosed that includes an engine section comprising a plurality of stages of variable vanes, and also includes first and second synchronizing rings (sync-rings). Movement of the first sync-ring adjusts vane angles of a first one of the stages of variable vanes, and movement of the second sync-ring adjusts vane angles of a second one of the stages of variable vanes. At least one sensor is configured to measure a condition of the gas turbine engine. A controller is configured to move the first sync-ring independently of the second sync-ring based on data from the at least one sensor.