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Looking for the best propeller for your aircraft? Choosing a propeller often comes down to compatibility with your specific aircraft and engine, your typical flight mission, and your performance needs.

One of the first places to start is by understanding the differences between constant-speed and ground-adjustable propellers. 

Constant-Speed Propellers: Optimizing Efficiency in Flight

A constant-speed propeller is designed to automatically adjust its blade pitch to maintain a constant rotational speed in every phase of flight. This helps ensure the optimal amount of power is used for every given situation. For example, during takeoff and climb, the pilot can set a low pitch (higher RPM) for maximum power. In cruise, a higher pitch (lower RPM) reduces engine workload and increases torque to enhance efficiency.

How It Works: Constant-speed props utilize a propeller governor, which responds to changes in engine speed and hydraulically adjusts the blade pitch to keep RPM constant. In this way, constant-speed props will automatically adjust the pitch of the propeller blades to take a greater or lesser “bite” of air depending on the aircraft’s speed many times throughout flight.

Benefits of Constant Speed Propellers:

• Enhanced Performance – Constant-speed props provide access to maximum engine power during all phases of flight.
• Fuel Efficiency – Maintaining optimal engine RPM reduces unnecessary fuel consumption.
• Reduced Engine Wear – Too little pitch in a propeller forces the aircraft engine to run faster to reach the desired speed. Constant speed props help protect high-performance engines from overworking.

Ground-Adjustable Propellers: Simplicity & Affordability

Whereas constant-speed propellers change pitch automatically in flight, ground-adjustable propellers operate as fixed-pitch in flight and can only be adjusted manually while on the ground. Before a flight, pilots can fine-tune their propeller’s pitch to their aircraft and specific mission, whether that’s optimizing for takeoff and climb power or cruise efficiency.

How It Works: Adjusting a ground-adjustable prop involves loosening the blades from the hub to rotate them to the desired pitch. For optimized acceleration and takeoff performance, pilots can set a lower pitch. For cruise efficiency, a higher pitch setting is preferable.

Benefits of Ground-Adjustable Propellers:

• Simple & Cost-Effective – Ground-adjustable props are less complex than constant-speed propeller systems. As a result, they are typically offered at a lower price point.

• Customization – Unlike fixed-pitch propellers, ground-adjustable props allow pilots to set the desired pitch before flight to match their specific mission. This can require some trial and error to find the right balance.

Which Propeller is Right for You?

If you prioritize dynamic performance, fuel efficiency, and smoother engine operation — especially if you have a high-performance aircraft engine — a constant-speed propeller may be the right choice for you.

If you have an experimental airplane or light sport aircraft and you’re looking for a cost-effective option that still provides blade pitch flexibility, you might consider a ground-adjustable propeller.

Ready to Upgrade Your Prop?

Hartzell Propeller is proud to offer high-performance constant-speed propellers and WhirlWind ground-adjustable propeller options for a wide range of aircraft — including experimental aircraft and light sport aircraft.

Get in touch with our team today to compare the best airplane propeller options for your mission, goals, and budget.