EnginesPropeller Systems

Constant Speed Unit (CSU)

A Constant Speed Unit (CSU) is a governor mechanism that automatically adjusts a variable-pitch propeller's blade angle to maintain a selected engine RPM. It uses oil pressure to change the pitch, optimising the propeller's aerodynamic efficiency across different phases of flight.

Key Points

  • •Controlled by the blue propeller lever in the cockpit.
  • •Manages engine RPM independently of throttle manifold pressure.
  • •Oil pressure is generally used to change blade pitch against centrifugal twisting moments or counterweights.

Exam Relevance

Required knowledge for operating advanced single-engine or multi-engine aircraft, particularly understanding power management and potential failure modes.

Related Terms

manifold pressurevariable pitch propellerpropeller overspeed

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Constant Speed Unit (CSU) | The Pilot Exam