Fixed pitch vs. constant speed propeller on RVs

Some pilots may think the performance of airplanes equipped with a fixed pitch propeller is never good in comparison to those with a constant speed propeller. That tends to be true because the airplanes that have the fixed pitch propellers are trainers with not so great power-to-weight ratios. Performance is just not something the designers had in mind. However, if pilots believe performance airplanes must always be equipped with constant speed propellers, these people have obviously not flown an RV...

It turns out I got used to how a well powered airplane performs after flying 8.5 hours in RV-6A N666RV (with a fixed pitch propeller) for transition training. When I went back to flying a Mooney M20J (with constant speed propeller) the following week, on takeoff I doubted whether the engine was developing full power. The engine was fine, it was just surprising how sluggish the acceleration of the Mooney is in comparison to the RV. This is true despite the Mooney having the "performance airplane" equipment (c/s prop) and the RV having the "trainer airplane" propeller.

Ultimately it comes down to power to weight ratio; in my example the Mooney just can't compete. 666RV weighs just 990 pounds empty and has 160 hp (even less horsepower will be produced on takeoff due to fixed pitch prop); while the Mooney has an additional 40 hp but it weighs almost twice as much. That's a lot more weight to accelerate down the runway, and it turns out the full 200 hp and 2700 rpm doesn't hide the weight very well. The Mooney gets the speed that it is famous for in cruise flight by having retractable gear, movable empennage, and other drag reduction techniques such that the lower power-to-weight ratio doesn't matter. RVs simply do it with horsepower.

The bottom line is: RVs have a greater power to weight ratio at less than 100% BHP than even certified airplanes with constant speed propellers. That provides plenty of excess horsepower to use for climb performance. It isn't compromised very much when it's turning a cruise propeller. Once your quick climb to altitude is finished, your propeller will already be set for efficient cruise operation. The fixed pitch option will save more than a few thousand dollars...it is the lighter weight option, and it's easier to operate and maintain.