Asa will confirm, I'm sure. But I am under the impression that Paul's operation (TAT) was all Garrett otters. Maybe they added a PT6 over the winter, but they were all Garrett's last I heard.

And here my pratts wear 4 blades

Yes single exhaust on the Garret, along with pitch locks as it is not a free turbine. Notice the Garret is in parked with a flat prop, and the Pratt is feathered. Generally speaking dual exhaust and feathered props on the free turbine Pratt or Walter, however the Walter comes stock with a dual action governor which relegated it to the Avia propeller. The Avia produces more thrust than the Hartzell, so there would be no benefit to swapping governors to run an inferior performing prop... well other than availability or serviceability.

Mostly just a somewhat educated SWAG... I'd even go as far as to guess the Garret is a -10, and the Pratt is a -34

Take care, Rob

If that is a Garrett, and the pilot didn't catch the pitch locks on shut down, he will be owing the other driver a case of his favorite beverage... at least that's how it works down here

Steelroamer wrote:OK, as a piston pounder I'm curious.... how can you tell the difference between the two?

Rob wrote:Looks like a blast. You in the Pratt or the Garret?

To expand on this, or clarify, in this class engine, a Garret is a direct drive turbine.
A Pratt is what we call a free turbine. In a manner of speaking, both run of exhaust gas for motivation, like a mini jet engine, but in the Garret, it is one continuous shaft until the gear box (hence direct drive). In the Pratt, the compressor section and power section are not physically connected by a shaft. You can literally hold on to a PT6 propellor while someone starts it. Just get ready to jump when you let go

Because of this direct connection, a Garret must be started with the propeller flat, or it will overtorque (think starting a standard transmission in 5th gear but worse). A Pratt ( kind of like like a centrifugal clutch mini bike) is not direct drive, so it can be started in feather, (call it in gear
..) which is where both of these engines will end up if you shut them off, feathered.
On shut down the pilot of the Garret, is tasked with catching the blades as they wind down on mechanical locks to secure them with no pitch. After start up he will introduce a slight reverse command which relieves the spring loaded locks and allows the blades to come out of the beta range.

Side notes;
Both of these engines have hydraulic driven props, and it is possible to spin up the Garret in order to put the prop on the locks if you missed it shutting down. Both have single action governors, in standard configuration, meaning a spring will feather them if you lose oil pressure (shut down).

Anyways... long story short, the props were the 'give away
As for the - numbers, that was just a guess based on airframe size and props in the picture. A -34 Pratt (750hp) typically runs a 3 blade hartzell (although there are 4 blade STC's). This seems like a good match to my mind for an otter sized aircraft. A -10 Garret typically runs a 4 blade Hartzell and is +/- 900hp, should make a mean otter sized aircraft.

Take care, Rob

asa wrote:

G44 wrote:How are your temp’s?

Kurt

They’re satisfactory to me. This is 100deg ROP at cruise power. Have been experimenting with leaning to different places in regards to peak EGT so see how the engine responds. My totalizer has been 8-12% off (high) when I fill up. So I think my fuel flow K factor needs to be changed but I’m making sure I have good data before changing anything. But I think my fuel flow is reading ~8% high.

As you probably know Maule has exhaust problems. I have owned my M7 235 since 2006. I was a new pilot. I started running 50 degrees ROP. EGT was way over 1400 degrees. I was going through flame tubes like crazy.

Over a 5 year period I settled in to running 1400 EGT which on my B4B5 is 125-150 ROP. The exhaust is happy now. I burn 12.5-15.5 GPH. All in at 7500 and above.

Way nice build. Congrats.

asa wrote:

G44 wrote:How are your temp’s?

Kurt

They’re satisfactory to me. This is 100deg ROP at cruise power. Have been experimenting with leaning to different places in regards to peak EGT so see how the engine responds. My totalizer has been 8-12% off (high) when I fill up. So I think my fuel flow K factor needs to be changed but I’m making sure I have good data before changing anything. But I think my fuel flow is reading ~8% high.

Thats where digital fuel senders/gage are useful for comparison. I have mine within a gallon of one another. Gives me warm and fuzzys.

Holy god, this plane sucks. Should’ve bought a tri-pacer

asa wrote:Holy god, this plane sucks. Should’ve bought a tri-pacer

I can help you out if you want by finding a real nice Tri-pacer down here, buying it, then flying it up to you for a straight across trade. No travel required by you. No messy money exchange. Easy peasy. Let me know if you want to do it.

CW

Awesome to see her out and about. Reminds me of Red Stripe beer too. That's not a bad thing.

The plane looks great in its natural habitat. Where are you playing around?

Joe

You actually got a day off to go play with her? Looks like a great time!

Kurt

twflyer wrote:The plane looks great in its natural habitat. Where are you playing around?

Joe

Thanks! Pics are from south central Alaska.

G44 wrote:You actually got a day off to go play with her? Looks like a great time!

Kurt

I get 2 days off a week at the new job and they’re even the same days every week. Living the high life these days.

Plenty of after work fun in the maule, the most capable airplane I’ve ever owned. It’s almost like someone spent thousands of hours purposefully customizing this plane in every way for me to do these things……..

Asa, Keep the photos coming!! Looks like you are having a blast!

Perfect tool for those perfect locations. Nice to see it doing what you built it to do. Enjoy.

⬆️ Wow, beautiful! ⬆️

Maule has been earning its keep this summer.

Amazing photos