Which of the following is NOT a function performed by the PMU?

The primary role of the PMU, or Power Management Unit, in the T-6B aircraft encompasses several critical functions related to engine performance and management. Among these functions is maintaining the engine and propeller within their operating limits, determining the available power, and fine-tuning the power requests to ensure optimal performance.

Option B, which states "Keep fuel balance within limits," is not a standard function of the PMU. While fuel management is crucial for aircraft operations, the PMU primarily handles engine power management, monitoring parameters such as speed and temperature, rather than specifically managing fuel balance. Fuel management is typically performed by other systems or components dedicated to monitoring and adjusting the fuel distribution within the aircraft.

In contrast, the other functions asked about directly pertain to the capabilities of the PMU. It is designed to ensure engine operations remain within specified parameters, provide a responsive power output relative to lever positions, and electronically communicate with the Fuel Management Unit (FMU) to adjust fuel flow as needed. Thus, the correct answer accurately reflects the role of the PMU in managing engine performance rather than fuel balance.