I am running a 80" Hartzell constant speed propeller on Bushwacker 2.0, I have wanted to try a composite propeller. I decided to try an MT 80" Ultra because that is what I was steered towards by Flight Resources with the guarantee it would out perform the Hartzell I was currently running. I am not going to just lay down $13,000 and assume it outperforms so we did a series of test one morning to determine if it really did.
Here are the results:
Today was test day for the MT propeller. I ran tests for the propeller I currently use versus the new MT propeller, both propellers are 80" long. I had two friends help, one is a mechanical engineer and has done a lot of testing for various aircraft projects. His name is Doug Keller and is fairly well known in the Super Cub world. We did all the tests on the Hartzell first. We started at 8:30 am and finished up testing with the MT by 10:45 am. We did not add any fuel so the MT would see the aircraft with the lightest load (not taking into account that the propeller is also 25 pounds lighter). These are obviously not scientific tests but were intended to see if there was a big difference between the two propellers. As you will see below the numbers do not support that the MT propeller will outperform my current Hartzell by any margin.
Pull test with load cell.
Hartzell pulled 785 pounds 2650 static using a True Tac
MT pulled 775 pounds 2680 static using a True Tac
We did a 150 foot take off run. Pull up to a line, go to full power, release brakes and make the 150 foot run at full power no flaps stick neutral. See results below:
Hartzell
5.50 seconds
5.32
5.23
5.08
Average= 5.28
MT
5.25 seconds
5.59
5.12
5.33
Average=5.32
I did a climb from a dead stop at sea level to 4000 msl climbing at 80 mph at 2600 rpm
Hartzell
3.14 Minutes
MT
3.16 Minutes
I put the airplane in a climb at 2000 msl and climbed to 3000 at 75 mph and saw a sustained climb of approximately:
Hartzell
1500 fpm (I used my Garmin G5 so hard to get very accurate reading with it)
MT
1500 fpm
In the end I decided that it was not worth the $13,000 to me. It was smoother, it had better braking action when I pulled the power and the weight off the nose did feel better when light. The problem with my airplane is I built it with the weight of engine and propeller in mind so taking weight off the nose when loading the airplane up is a negative. I run out of aft CG before I run out of room. If I had a Super Cub and wanted to run a constant speed propeller this would be one propeller to look at. The guys at Flight Resources were top notch with regards to customer service.