Complex sentence: The air then passed through four compressor stages and was split by movable vanes: some of the air entered the compressor fans ("core-flow" air), while the rest of the air went straight to the afterburner (via six bypass tubes).
Split into simpler sentences: The air then passed through four compressor stages and was split by movable vanes. Some of the air entered the compressor fans ("core-flow" air), while the rest of the air went straight to the afterburner (via six bypass tubes).