Through which path does the PCL provide its input to the HMU?

Through which path does the PCL provide its input to the HMU?

• A. LDS
• B. PCL through the PAS
• C. PCL through the torque motor
• D. PCL via NP sensor

Answer: (B)

The PCL input to the HMU goes through the PAS. The Power Control Lever position is translated by the Position/Angle Sensor (PAS) into a calibrated signal that the Hydromechanical Unit uses to schedule fuel flow and control turbine speed. The HMU then commands its internal components, like the metering valve via the torque motor, to meet that command. The NP sensor and other components provide rotor speed feedback or act as separate functions, not the path for PCL input. So the correct path is PCL through the PAS.

The PCL input to the HMU goes through the PAS. The Power Control Lever position is translated by the Position/Angle Sensor (PAS) into a calibrated signal that the Hydromechanical Unit uses to schedule fuel flow and control turbine speed. The HMU then commands its internal components, like the metering valve via the torque motor, to meet that command. The NP sensor and other components provide rotor speed feedback or act as separate functions, not the path for PCL input. So the correct path is PCL through the PAS.