Figure 7.13. Fuel Control System.
The droop compensator moves the governor Lever any time the pilot's collective stick is
increased or decreased. This is necessary to maintain the N2 rpm the pilot has set with the N2 actuator.
When collective pitch is increased, the power requirements are increased, and N2 rpm droops slightly.
The governor senses the N2 droop and it signals the gas-producer fuel control to meter more fuel. As
fuel flow increases, N2 returns to the setting of the power-turbine governor. When collective pitch is
decreased, the power requirements are decreased, and N2 increases slightly. The governor senses the N2
increase and signals the fuel control to meter less fuel. As fuel flow decreases, the N2 decreases to the
setting of the power-turbine governor.