Hartzell 3 blade Trailblazer

[PaulSA]

You guys seem to be using very large props. I have a IO540 powered RV10 which has the MTV12B/193 (76").

Sweet prop, very smooth. Weight is about 10lb less than the equivalent Hartzell aluminum 2 blade.

[Mark Goldberg]

Go fast airplanes are happy with a smaller diameter blade. For take off thrust and climb - a bigger diameter prop helps a lot. Mark

[Gerhard Rieger]

Hi all, How durable is the composite props in comparison to aluminum on gravel?

[JimParker256]

There was a good discussion on this in the Backcountry Pilots forum (or possibly the SuperCubs forum) where the consensus seemed to be that the nickel-edged composite props did better than an all-aluminum prop. Both require some occasional repairs, but repairs to the composite prop (usually the back face) were easy to do and did not result in a mis-shaped prop. The aluminum blades have to be filed down to smooth out the dings, which changes the "lifting surface" profile.

By the way, the nickel-edged props did WAY better than the stainless-edged props, and that's why most of the composite manufacturers only offer nickel these days.

[Gerhard Rieger]

I have a MTV14 76' four blade MT prop and a IO-540 max Rpm 2575. your comments please

[Bdflies]

Gerhard, where does the RPM limitation come from? Is that the published limit for the propellor? Was the engine on a plane, whose redline was 2575?
what does the engine data plate state?
Some aircraft have reduced engine speed, to comply with noise regulations. I'd be surprised if that redline was a propellor or engine manufacturer's limit.

Bill

[Gerhard Rieger]

Bill, the engine come from the astec 250 and its limited to 2575 rpm and the prop limit is 2700 rpm, at 2575 rpm the engine produce 250hp, I believe the engine can do 2700 rpm. MT in Germany said that with the right ajustmend to the prop they will match, your input will be welcomed

[Bdflies]

Note: I'm not any sort of 'expert or authority' on this matter. Engine/prop stuff is a serious matter. If a prop sheds a blade or the crankshaft breaks, it'll just ruin your day! Don't take any bold actions, because some guy names Bill said it was alright. Just sharing my thoughts.
Some research indicates that you have an IO-540-C4B5. That engine has a counterweighted crankshaft, to operate with a Hartzell prop. It's my understanding that the MT props don't require counterweights, but the existing counterweights aren't a problem, if you use a MT. I would suggest that you contact MT to confirm that.
If you use the prop governor that came on the engine, it will no doubt be set for 2575 max rpm. (Here's where I go off the reservation and offer an opinion, supported by nothing.). If it were mine, I'd adjust the governor for 2700 rpm. That extra 125 rpm makes more difference than you'd think.
Now, please contact MT, to be sure the prop is compatible with your counterweighted engine. If you're going to Oshkosh, ask one of the Lycoming guys if there's a reason not to run your engine to 2700.

Bill

[Gerhard Rieger]

Thanks Bill, I like to get as much advice as possible, I've discussed the match with MT in Germany and they advised me to take it to a local agent to ajust the proppeller for the engin. I also agree with you and a friend who flies commercially , also a home builder told me that the rpm can be changes to 2700. I will make contact with Lycoming and confirm with them. thanks again

Gerhard

[Battson]

Some aircraft have reduced engine speed, to comply with noise regulations. I'd be surprised if that redline was a propellor or engine manufacturer's limit.
Bill

This was the case with my prop, it was pitched for a Cessna 182 which maxed out at 2450 for European noise regulation (or something like that, I forget).
We just replaced the fine pitch stops, adjusted the governor, and set it to exactly 2750rpm (Lycoming limit is 2700 +/- 50). There was no change to the engine.

[Gerhard Rieger]

Thanks Jonathan, that make a lot of sense to me, thanks Bill also for your input

[Battson]

Our new Trailblazer turned up a couple of weeks ago. It's an 83" two blade prop, weighing 41.2 pounds including our 3" prop extension. Pretty nice looking blades! They are very thin with a long chord, which isn't possible with aluminium. Although I do have to admit the MacCauley hub is a much more attractive design than Hartzell's, not that you'll ever see it hidden under the spinner...

I was pleased to learn that Hartzell are using Ni-Co leading edges on the Trailblazer, which can be replaced in the field apparently.