Definition
The first turbine stage (or stages) located immediately downstream of the combustion section in a gas turbine engine. It extracts energy from the hot, high-pressure gases leaving the combustor and uses that energy to drive the high-pressure compressor through a connecting shaft. In a multi-spool engine, the high-pressure turbine and high-pressure compressor rotate together as a single unit, independent of the low-pressure spool.
Plain English
The first set of spinning blades the hot gases hit after the combustion chamber. These blades capture energy from those gases and use it to spin the engine's main compressor that feeds the combustor.
Context Anchor
Seen in turbine engine descriptions, maintenance discussions, and reports about engine temperature, power loss, or turbine damage.
Derivation
The term describes its position in the gas path. The gases leaving the combustor are at their highest pressure and temperature, so the turbine stage that meets them first is called the high-pressure turbine. The next turbine downstream sees lower pressure gas and is called the low-pressure turbine.
Why Pilots Care
It converts combustion energy into compressor drive power; damage or inefficiency directly reduces thrust and can force an engine shutdown.
Analogy
Think of a windmill placed in a very hot, fast-moving stream of gas. The gas makes it spin, and that spinning is used to turn another part of the engine.
Intuition Check
High-pressure does not mean a pressure setting the pilot adjusts. Here it identifies the turbine section closest to the hot, high-pressure gas leaving the combustion section.
Example Sentence 1
The high-pressure turbine drives the high-pressure compressor through the inner shaft, while the low-pressure turbine drives the fan and low-pressure compressor through the outer shaft.
Example Sentence 2
Mechanics inspected the high-pressure turbine for heat damage after the engine run.