I covered this on the blog, but we’re going to be installing a new MT hydraulically-actuated propeller this weekend with help from the airport’s maintenance shop. The constant-speed propeller will allow us a lot of utility that we didn’t have with the Catto, though the plane performed pretty well on the fixed-pitch Catto.
We have a lot of horsepower (Lycon dyno tested our IO-540 at 316 HP at 2,759 RPM, and it’s the lighter, normally 260 HP, case) but we could only spin the Catto about 2100-2150 static, and got about 2250 RPM on the take-off roll so there was a lot of power still in the engine unavailable. Engine power is directly proportional to the RPM, so at 2200 we’re getting a fraction (according to the chart about 163 HP) of the total power the engine would produce if it could attain 2,700 RPM, which the MT will do. In fact, when we flew with our friend Mark Riley, his plane felt like a rocket sled in comparison, and leaving 100 HP on the table will do that to you. Even with that, single pilot we were off in under 1,000′ of runway with the Catto, and Beth and I could get off in about 1,200′ typically. And if we leaned out the Catto would run over 180 kias for us, so overall this was a great fixed pitch prop. But on a hot day anywhere near gross we would eat runway like a pack of tigers on a fresh kill. The MT will help us get off the ground quickly, even when heavy, and will help steepen our approach by adding drag. It should help our weight and balance as well, as the governor and prop should be quite a few pounds heavier. Here are some pictures.
|Governor:||Aero Tech PCU5000X||Serial#:||11303097|
Posted By: Brett FerrellFriday December 16th, 2011 at 10:05 AM