Question

To reduce the power output of an engine equipped with a constant-speed propeller and operating near maximum BMEP, the

a) Decrease the pitch of the propeller blades
b) Increase the pitch of the propeller blades
c) Increase the throttle setting
d) Use a larger-diameter propeller

Answer 1

To decrease engine power output with a constant-speed propeller, you increase the pitch of the propeller blades, which reduces the rotation speed of the blades and thereby reduces the power output.

Step-by-step explanation:

To reduce the power output of an engine equipped with a constant-speed propeller and operating near maximum Brake Mean Effective Pressure (BMEP), you would b) Increase the pitch of the propeller blades. By increasing the pitch, the angle at which the blades cut through the air is increased, resulting in a larger bite of air per rotation, thereby decreasing the engine rpm as more torque is needed to turn the propeller. This action, governed by the propeller control in the cockpit, ultimately reduces the power output without changing the engine's throttle setting.