Aircrewman Mechanical (AWF) Test 3 Practice

In a turboshaft engine, two turbines extract energy from the hot gases to do two jobs: drive the compressor and provide power to the output shaft. The turbine that powers the compressor is the gas generator turbine. It sits upstream and drives the high‑pressure compressor (and accessory gear) so the engine can maintain the airflow and the combustion process needed for stable operation.

The second turbine is the power turbine, which sits downstream and takes energy from the remaining gas flow to drive the output shaft that provides useful mechanical power to the helicopter or other load. This turbine is not directly tied to the compressor; its job is to convert part of the gas energy into shaft power.

Other terms like turboprop or turbojet describe engine types rather than the specific turbines inside a single turboshaft, and “compressor turbine” or “exhaust turbine” aren’t the standard way these stages are referred to in typical turboshaft designs. In short, the two turbines are the gas generator turbine and the power turbine, each serving its distinct role within the same gas path.