Turboprop info....

Roger Roger

Paid to sleep, fly for fun
Are PT6's really that fragile? We've done some beating on our -61's and the mechanic says they seem to be holding up fine.
Understand that most of this is just banter/trash talk. Though the statement about having to pull a -114A due to FOD was 100% true.
 

gotWXdagain

Highly Visible Member
Roger might have a different opinion but from talking to some of our mechs that have wrenched both, they generally prefer the Pratt.
 

Roger Roger

Paid to sleep, fly for fun
Roger might have a different opinion but from talking to some of our mechs that have wrenched both, they generally prefer the Pratt.
My opinion is heavily clouded by the very shoddy installation of the PT6 in the Caravan. I’m told that if I wrench on the PC12 that opinion is subject to change.
 

gotWXdagain

Highly Visible Member
My opinion is heavily clouded by the very shoddy installation of the PT6 in the Caravan. I’m told that if I wrench on the PC12 that opinion is subject to change.
Our mechs do seem to like it. I like it, I think the kerjillion flow reversals make perfect sense for the application (makes the engine smaller front-to-back), I like that the power turbine is a free-turbine (EPU Start ::check:: observe the lights dimming on several city blocks ::check:: Fuel flow, light off, observe FNG ramper scramble for his earmuffs), the power shaft between the turbine and the reduction gearbox is only a few inches long (giggity).
 

milleR

Well-Known Member
Our mechs do seem to like it. I like it, I think the kerjillion flow reversals make perfect sense for the application (makes the engine smaller front-to-back), I like that the power turbine is a free-turbine (EPU Start ::check:: observe the lights dimming on several city blocks ::check:: Fuel flow, light off, observe FNG ramper scramble for his earmuffs), the power shaft between the turbine and the reduction gearbox is only a few inches long (giggity).
I won't start up if the rampers don't have hearing protection on. I actually keep a bunch of disposable foam plugs on hand that I can pass through the little access door thingy just in case they forgot their own.
 

Lawman

Well-Known Member
I won't start up if the rampers don't have hearing protection on. I actually keep a bunch disposal plugs on hand that I can pass through the little access door thingy just in case they forgot their own.
Blessings be with you....


Also with the people who when deplaning passenger from a King Air or similar type drop the flaps if they are going to keep running. For some reason the Navy is not a fan of that technique and it’s loads of fun to unload luggage in front of a non feathered prop.


Sent from my iPhone using Tapatalk
 

Roger Roger

Paid to sleep, fly for fun
Our mechs do seem to like it. I like it, I think the kerjillion flow reversals make perfect sense for the application (makes the engine smaller front-to-back), I like that the power turbine is a free-turbine (EPU Start ::check:: observe the lights dimming on several city blocks ::check:: Fuel flow, light off, observe FNG ramper scramble for his earmuffs), the power shaft between the turbine and the reduction gearbox is only a few inches long (giggity).
331 is shorter front to back than the PT6 by a long shot, and you only have 1 gearbox.
 

Roger Roger

Paid to sleep, fly for fun
And Pratt’s don’t need fusion power just to start the engine when the temperature drops below boiling.
Honealty, maybe it’s low-time engines and such, but we haven’t had any issue with that even doing parallel only starts averaging 2.2 cycles per hour. Just gotta take care of the batteries and cycle them through cap check/desulfate.
 

milleR

Well-Known Member
Honealty, maybe it’s low-time engines and such, but we haven’t had any issue with that even doing parallel only starts averaging 2.2 cycles per hour. Just gotta take care of the batteries and cycle them through cap check/desulfate.
That’s amazing.
 

Roger Roger

Paid to sleep, fly for fun
That’s amazing.
Before we started tracking the batteries we had a couple issues, but even then the worst one was a headset-separator failure. Now we (I say we, but really it’s “they” now) perform a capacity check on the batteries every 400 hours, and usually when that 400 hours comes up we’re swapping out for our spare set, that way they can sit on desulfate for a few weeks. Haven’t had any battery issues since, and the batteries typically gain a few percent from desulfating for 10 days or so.
 

milleR

Well-Known Member
Before we started tracking the batteries we had a couple issues, but even then the worst one was a headset-separator failure. Now we (I say we, but really it’s “they” now) perform a capacity check on the batteries every 400 hours, and usually when that 400 hours comes up we’re swapping out for our spare set, that way they can sit on desulfate for a few weeks. Haven’t had any battery issues since, and the batteries typically gain a few percent from desulfating for 10 days or so.
I’ll have to check to be certain, but I’m pretty sure battery inspection on the Mits is done every 200 hours.

But engines are funny- I always start #2 first with a GPU because the cabin door is on the left; but that thing hates battery starts so it’s #1 off the batteries because the spin up is much faster, like a solid 5 seconds less of the SRL bouncing off 720.

Series is no problem either side but I can hear my starter gens cussing me out in the process.
 

Autothrust Blue

“Bayonet!”
Or that bullet gets anywhere near the fragile first compressor stage of the pratt.
While the Garret eats FOD for breakfast lunch and dinner for 8 years straight.
Oh and heaven forbid the pt6 is parked within 100 miles of an ocean. 1st stage compressor corrosion city!
"The purpose of the bend in the intake is to keep FOD, like birds, ice and Canadair Regional Jet parts, from entering the engine compressor section."

- Jon Graff
 
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