What type of propeller is set by the manufacturer for best overall performance?

The correct choice is the fixed pitch propeller. This type of propeller is designed with blades that are set at a specific angle and cannot be altered during flight. Manufacturers select the pitch angle of a fixed pitch propeller to optimize performance for a general range of conditions. This means they aim for a balance between takeoff, climb, and cruise performance.

Fixed pitch propellers are typically simpler in design and easier to maintain compared to other types, devoid of the intricate mechanisms required for pitch adjustment. As a result, they are commonly used in many training aircraft and small general aviation aircraft. The manufacturer sets this configuration to help ensure that the aircraft performs well under typical operational conditions without the need for the pilot to make adjustments.

In contrast, variable pitch propellers allow for adjustments in the blade pitch to optimize performance for different flight conditions, which may not be ideal for all situations. Fine pitch and coarse pitch refer to specific angles that can be set, but these options are often utilized in more advanced or specific performance needs rather than the best overall performance across various flying conditions.