Moving the HPC1 VIGV’s of a GE90-115’s Fan Hub Frame.
Quite rare opportunity to see the insides of a jet engine!
The GE90-115 has one VIGV and four VSV stages, for the high pressure compressor.
The VIGV’s are moved with the VSV’s by an unison ring (one for each stage), and actuated by two fuel controlled linear actuators. They help controlling the angle of attack of the air rushing on the compressor blades, avoiding a stall condition (leading to an engine surge).
They go from fully closed (idle power) to fully open (take-off power).
Around the VIGV’s, you cas see some parts of the VBV system: one of the two actuators (big grey thing, at the bottom right corner), and some vent scoops (brownish ducts, all around the frame).
For more informations and details about VBV’s, VSV’s and VIGV’s (and jet engine explanation in large), I higly recommend you AgentJayZ’s channel: