The DEC input to the HMU is delivered through which mechanism?

The DEC input to the HMU is delivered through which mechanism?

• A. PCL through the PAS
• B. LDS
• C. DEC through the torque motor
• D. NP overspeed switch

Answer: (C)

DEC input to the HMU is delivered through the torque motor. The DEC provides an electrical command that the torque motor inside the Hydromechanical Unit converts into precise mechanical movement. That movement positions the metering valve so fuel flow and timing are adjusted to meet the commanded engine torque and speed. This electrical-to-mechanical conversion is what ties the digital control (DEC) to the hydraulic fuel control that ultimately governs engine power. The other pathways aren’t correct for delivering DEC commands: the PCL through the PAS is a manual flight control interface, while LDS and the NP overspeed switch are sensors or protective devices, not the DEC signal path to the HMU.

DEC input to the HMU is delivered through the torque motor. The DEC provides an electrical command that the torque motor inside the Hydromechanical Unit converts into precise mechanical movement. That movement positions the metering valve so fuel flow and timing are adjusted to meet the commanded engine torque and speed. This electrical-to-mechanical conversion is what ties the digital control (DEC) to the hydraulic fuel control that ultimately governs engine power.

The other pathways aren’t correct for delivering DEC commands: the PCL through the PAS is a manual flight control interface, while LDS and the NP overspeed switch are sensors or protective devices, not the DEC signal path to the HMU.