Single blade propellers?

[David MacRay]

I have never seen one before today.

Here’s an AOPA video clip on it.



I believe more blades are better and I like odd numbers such as three and five, but it’s interesting that at one time someone theorized a single blade would be better.

[Slick Goodlin]

Two adults up in their J-2? Dang, I need to do a compression check or something I guess…

As for the single blade prop, they’re theoretically more efficient but they bring along baggage that makes them problematic in reality. In a nutshell the theory is that more blades see greater efficiency losses through the tips. When a prop has three or more blades it’s often because they’re constrained in diameter either due to tip speed or some physical limit like the landing gear length or space available before the tips hit the fuselage or something.

The Everel prop itself was later re-worked into an automatic variable pitch two blade unit sold for years as the Aeromatic.