Primary Systems 2 Practice Test

The main idea here is how the Power Management Unit (PMU) controls and protects the engine. The PMU’s job is to translate the pilot’s power request into a safe, usable power level while keeping the engine and propeller operating within their limits. It shapes the response so that as you move the power control from idle toward maximum, the engine responds in a nearly linear and predictable way. It also monitors important parameters to ensure operation stays within prescribed bounds, including factors like fuel state to maintain safe operation. What the PMU does not do is fine‑tune the power request or directly send an electronic signal to the Fuel Metering Unit. Fine tuning the power and managing precise fuel metering are responsibilities of the engine control system (the FADEC/ECU) which then drives the Fuel Management Unit (FMU) to meter fuel accordingly. So the PMU provides protection and a smooth, linear mapping from pilot input to available power, while the actual metering and final power adjustment are handled by the engine control system.