Few updates - Whirlwind Prop

Sorry for the delay in writing.

Some of you know and Randy eluded to it some time ago. We have been doing some testing of different props specifically for our SLSA aircraft. Our goal with the SLSA was to have an USA Built and manufactured SLSA aircraft. Well, we did have to choose the Rotax engine for specifically weight reasons.. We really wanted to use the new Lycoming or Continental but the weights would be and absolute minimum of 40 lbs heavier. so when it came to American manufactured props for the Rotax there were not many choices that was; 1 - willing to meet the ASTM standards, 2 - fairly quickly ground adjustable.

We started doing some preliminary tested and knew from experience that the 2 blade Sensenich was an option but 2 blade props and our Kitfox's just do not seem to be as smooth as the 3 blade props. There is a frequency from the 2 blades that will resonate into the fuselage via the fabric and actually drums. It varies considerable with RPM's but it is definately there.

So, is there a 3 blade prop that meets our requirements ? Whirlwind has a very respected propellor that has been used in the RV world and in the aerobatic world for some time. With an introduction to Jim (owner of Whirlwind) we started talking about using one of his ground adjustable props. He did not have a prop for the Rotax and within a short amount of time a quick adjust - 2 blade prop was on one of our aircraft. Boy did this look great and the performance was wonderful but as with any other 2 blade there was that familiar vibration. Before I go too much further lets just say that Jim is great to work with and he manufactures a great product.
A new hub was made and a 3 blade prop is on the aircraft. Adjustment takes about 10-15 minutes using a smart level. We have seen good numbers in climb and cruise when pitched accordingly... over 1200 fpm climbs and 128 TAS cruise. It is currently set at a compromise pitch setting and we have 850fpm climb and 114 TAS. Composite prop with nickle leading edge. I think this will also make a great prop for float operations as well. Cost is $1900.