Definition
A turbine engine that uses both axial-flow and centrifugal-flow compressor stages in series. Air first passes through one or more axial stages, where rows of rotating and stationary blades compress it as it moves straight through the engine, then enters a centrifugal stage, where an impeller flings the air outward to compress it further before it reaches the combustion section.
Plain English
A jet or turboprop engine that squeezes incoming air in two different ways, one after the other. The first part pushes the air straight through using rows of small blades, and the second part spins it outward using a disc-shaped wheel to squeeze it more before it reaches the burner.
Context Anchor
Seen in turbine engine descriptions and maintenance discussions about compressor design.
Derivation
Hybrid means a mix of two different things. Axial means along the axis (straight through), and centrifugal means moving outward from the center. The name simply tells you the engine combines both compressor styles in one unit.
Why Pilots Care
Hybrid compressors give engines the efficiency of axial stages with the simplicity and durability of a centrifugal stage, which is why many small turboprops and helicopter engines use this design. Recognizing the type helps pilots understand performance characteristics and start procedures specific to their engine.
Intuition Check
Hybrid does not mean the engine is partly electric. Here, hybrid means the compressor section combines two different ways of compressing air.
Example Sentence 1
The PT6 turboprop uses a hybrid compressor engine, with three axial stages feeding a single centrifugal stage before the combustion chamber.
Example Sentence 2
Technicians inspected the hybrid compressor engine for blade damage after a bird strike.