What happens to the pitch of a propeller when power is increased?

When power is increased in a propeller system, the pitch generally decreases. This happens because increasing the power typically results in a need for the propeller to adjust its angle of attack to maintain optimal performance. A decrease in pitch allows the propeller to operate more efficiently at higher power levels, facilitating a better thrust-to-power ratio.

In many propeller systems, including variable pitch propellers, a pilot or automated system can adjust the pitch to achieve the desired aerodynamic performance; decreasing the pitch helps the propeller achieve higher RPMs, thereby increasing thrust conforming to the characteristics of the power being utilized.

A constant pitch would not allow for optimal performance under changing power conditions, and changes that are random would not effectively harness the principle of adjusting pitch based on power input. Thus, the dynamics of increasing power necessitate a reduction in pitch to enhance propeller performance and efficiency.