Definition
A stationary ring of airfoil-shaped vanes located between the combustion section and the first turbine wheel of a gas turbine engine. They direct the high-velocity, high-temperature combustion gases onto the turbine blades at the correct angle and accelerate the flow by acting as convergent nozzles, converting some of the gas pressure into velocity.
Plain English
A fixed set of small curved blades sitting just before the spinning turbine wheel. They aim the hot exhaust gas at the right angle and speed it up so it hits the turbine blades efficiently.
Context Anchor
Seen in gas turbine engine maintenance, especially during turbine section inspection, hot-section inspection, and engine performance troubleshooting.
Derivation
The word 'vane' comes from Old English 'fana,' meaning a flag or blade. 'Guide' tells you their job — they steer the gas. 'Inlet' refers to the entrance of the turbine section. So: blades that steer gas into the turbine inlet.
Why Pilots Care
Correct vane alignment maintains turbine efficiency, prevents overheating, and avoids blade damage from off-angle gas flow.
Analogy
Think of a garden hose nozzle aimed at a waterwheel. The nozzle both points the water and speeds it up so the wheel spins efficiently. Inlet guide vanes do the same job for hot gas hitting the turbine.
Intuition Check
Do not read “inlet” as the airplane’s front air intake. Here it means the entrance to the turbine section inside the engine, where hot gas is being directed into the turbine blades.
Example Sentence 1
During the hot section inspection, the technician checked the turbine inlet guide vanes for cracks and erosion.
Example Sentence 2
During engine start the turbine inlet guide vanes directed the hot gases onto the first-stage blades at the design angle.