Figure 7.12. Fuel Pump and Filter Assembly.
The power-turbine governor (N2) is not required for starting or ground idle operation,
but it is required for speed governing of the power turbine rotor. The gas-producer fuel control and the
power-turbine governor are connected together by two pneumatic lines, labeled PG and PR in figure 7.11.
The power-turbine governor, driven by the power-turbine gear train, senses compressor discharge
pressure (PC). The power-turbine governor lever, as shown in figure 7.14, is positioned by the helicopter
droop compensator or the N2 actuator. The power-turbine governor is required for speed governing of
the power turbine rotor (N2). The N2 rpm at which the power-turbine governor will govern is under the
control of the N2 actuator. Normally, the power-turbine governor is operated at 100 percent N2.
However, the pilot can select a setting of the governor either higher or lower than 100 percent N2.