Definition
A gas turbine engine designed to deliver its power through a rotating output shaft rather than as jet thrust. Hot gases from the combustion section drive a turbine that is geared to an external shaft, which in turn drives a load such as a helicopter rotor system or a propeller through a reduction gearbox.
Plain English
A jet-style engine that doesn't push the aircraft with its exhaust. Instead, the spinning hot gases turn a shaft, and that shaft drives something else, like a helicopter's rotor.
Context Anchor
Seen in helicopter powerplant discussions, engine limitations, maintenance procedures, and systems descriptions that describe how engine power reaches the rotor system.
Derivation
From 'turbo,' meaning powered by a turbine (a wheel spun by flowing gas), and 'shaft,' the rotating rod that delivers the power. The name describes exactly what it does: a turbine engine whose useful output is shaft rotation.
Why Pilots Care
Helicopter pilots depend on turboshaft engines to turn the rotor system that produces lift and control, making engine condition directly tied to flight safety.
Analogy
Like a jet engine that uses its spinning parts to turn a driveshaft rather than push the aircraft forward with exhaust.
Intuition Check
Do not think of a turboshaft engine as mainly pushing the aircraft with exhaust like a jet. Its main job is to make shaft power that turns something else.
Example Sentence 1
The helicopter is powered by a turboshaft engine that drives the main rotor through a reduction gearbox.
Example Sentence 2
Maintenance checked the turboshaft engine oil pressure during the daily inspection.