The is NO substitute for horsepower!! Then again where will the 900hp have to land vs the 635hp? Those extra ponies have to be fed.

TD

The Garrets are pretty fuel efficient, compared to the P&W as well. You don't HAVE to use 100 % power ALL the time, either.

MTV

Mike's on it. Garrett's sip it compared to a Pratt. Usually the fuel burn for the Garrett is the same as the next lower Pratt. Specific for you; The PT-6-34 rated at 750 hp. on my Thrush usually works at between 48 and 55 gallons an hour, the -10 Garrett on the same fuselage rated at 900 hp. works at the same 48 to 55 gallons an hour.

Same story with my 550 HP CAT in my rig. Sips about 6.5 - 7 MPG. Our 2002 Pete we had a few years ago with a 475 CAT geared about the same, siped a wooping 5-6 MPG . We got rid of the Pete and I'm still driving the 99 KW with the 550 CAT.

Anyway, that's as much off topic I'm going.

Wow, did not know that.

In light of what you guys are telling me, why would anyone strap a P&W on the nose when a Garrett is available? Weight, price, ???

Might be a good sales video for different kinds of floats also??
Kind of like watching a 180 and 260 Maule take off at the same time.
different floats and props make a drastic difference.
wonder how much the 275 hp costs?
Sure would be nice to have that green and white one tho!!!!!
And the funds to feed it!

I think my favorite part was the guy backing out of the mooring spot.

Beta!

There's only one make and model of float that's approved on the Caravan.

Why are the PT-6 engines so universally adopted, when the Garretts have many advantages? I dunno. The Garrett (Honeywell) engines now are permitted to go to 9000 hours on condition, with no hot section. PT 6 is still 4500 tbo, I believe.

The PT 6 is a free turbine, whereas the Honeywell is a geared turbine. Honeywells are NOISY as hell.

PT-6 have a little spool up time (time between movement of the thrust lever and actual delivery of thrust) whereas the Honeywells pretty much provide instantaneous thrust. The later PT 6 engines are much better in this regard than the earlier Pratts, though.

The Honeywells were quite a bit CHEAPER than the PT-6s a few years ago.

So, why are virtually ALL the current manufacturers of turbine airplanes installing PT-6 engines? Hopefully, someone else has an answer.

MTV

Couple of those Garrett powered Otters around here. Extremely impressive.

gb

Couple of those Garrett powered Otters around here. Extremely impressive.

gb

* I am not a turbine guru *

but here's some thoughts to ponder on the garrett / honeywell ...

If you are considering it from a conversion stand point, or a 'bush' stand point... It is almost always longer and heavier than an equally powered Pratt, low weight is one of the beauties of turbine power, but here the nod goes to the Pratt
Because you are spinning the whole she bang on start up, it requires external power OR many GYNORMUS batteries... (read: more weight)
If you use it in an application of many short hops both your neighbors and your ground crew will be unhappy to hear you every time you come and go, as evident by the current crop of ads for seasonal operators in the midwest for next summer, several state 'Garretts need not apply'
The TPE331 was designed for airplanes that fly in the flight levels, as evident by the fact that when you are looking at the nose of the airplane you are looking at the number one first stage compressor wheel... IOW they are not designed to be operated in a FOD potential environment... In other threads we hash out air filters, these things have zip...nada ... zilch, Conversly the Pratts were designed by the same breed of north americans that gave us the beaver, otter, twotter... you get the idea ...They understand terms like 'bush' and 'workhorse'...
A prop strike on anything sucks, it will suck wayyyy more on a Garrett, ever notice the Garrett guys spinning their props after shutting down, (or dry motoring the engine in other apps) that's because the shaft that runs down the whole enchilada is not much bigger around than your thumb, and yes all 750 or more HP are hanging on that, sooo when you shut the thing down and it starts to cool, an un even cooling can bow that shaft . To be fair here, I personally ran a Garrett through a tree, and a teardown revealed no damage, other than the props..
Nearest I can tell there is nothing more economical about maintaining a Garrett...
Hot loading them sucks, because you don't feather them, and most don't like to be 'flat' or the will heat up, so you keep some pitch in it, and it hunts back and forth and you don't get out to wizz for fear that it will drive away...lol
well... like I said, not a turbine guru, but there are a few on the board
Take care, Rob

The PT6's have a 3600 hr. TBO which is up from 3,000 a few years back. Hot's have gone from 1500 to 1800. Most models. If you believe the P&W literature, a Garrett/Honeywell TPE-331 will have an inflight shut-down rate 3 times higher than the Pratt. The PT6 draws it air from the rear and and bird/ice ingestion are considered somewhat non-events. The safest turboprop turboprop statistically (B200 King Air) has Pratts and the least safest (MU-2) has the Garretts. I think the public perception has always favored the PT-6 and people are comfortable with them even though they burn more fuel and cost a boatload more to overhaul.

The newer TPE-331 Garretts are very reliable, but all Garretts direct air straight into the engine core for immediate power. Birds and large chunks of ice/fod can shut one down in an instant. Couple that to a marked airframe (MU-2 or heavy loaded Metro-Merlin) and the accident rates suffered. Early Garretts had less reliability and helped coin the term "Garrett Grenades". You will often see pilots who fly 331's get their passengers on their way and turn around to hand prop the engines through a few cycles to avoid a condition where the hot oil can actually bend or warp the axial shaft. I'm not sure if that has been fixed or not but it appears that the engines like to be massaged a bit more than a PT6. As mentioned earlier, 331's are ear-splitting noisy. The old joke was that the 331 was born out of a secret experiment at Garrett of turning fuel into noise.

I like the 331's and PT-6's both so I'm going to have to decide between the TTCaravan or the Kodiak soon...

I got to fly right seat in Jim Chryslers Caravan on straight floats...the one from Yellow Knife. It was fun and a real eye opener. The Beta was very cool, too. This was back in the 90's when I think the P&W's were only 600 ponies. The HP looks AWESOME.

I agree with Rob, the PT-6 is a real workhorse! A better fit in my opinion with the type workhorse aircraft, caravan, otter ect. The inertial seperator protects pt-6's from a lot of FOD damage you have to be careful of in a standard axial flow compressor.

The 331 is more likely to have hot start issues with a old/weak battery. They draw more amps on start up because of having to spin the prop & gearbox, where the pt-6 has a free turbine. There are STC's in Pt-6 applications to replace the NiCad with a lead-acid, less expensive to maintain & replace than a NiCad & not prone to thermal runaway. I don't think that's possible in a Garrett. Also Tha ITT's are touchier in a 331. Both of these can lead to expensive HSI's even though the interval is less in a P&W.

The Garrett's are sure noisy! I think they have a much higher N1 speed than the Pratt. Quick turn on a PT-6 aircraft are nice in Beta or slightly reverse & less ear splitting whine.

They are slower to spool up, but both seemed to get the 8000 pounds off the water just fine. I'd like to know what the difference in gross weight & cruise is after the conversion? I sure wouldn't mind having either one & sticking to bigger lakes!

I agree with Rob, the PT-6 is a real workhorse! A better fit in my opinion with the type workhorse aircraft, caravan, otter ect. The inertial seperator protects pt-6's from a lot of FOD damage you have to be careful of in a standard axial flow compressor.

The 331 is more likely to have hot start issues with a old/weak battery. They draw more amps on start up because of having to spin the prop & gearbox, where the pt-6 has a free turbine. There are STC's in Pt-6 applications to replace the NiCad with a lead-acid, less expensive to maintain & replace than a NiCad & not prone to thermal runaway. I don't think that's possible in a Garrett. Also Tha ITT's are touchier in a 331. Both of these can lead to expensive HSI's even though the interval is less in a P&W.

The Garrett's are sure noisy! I think they have a much higher N1 speed than the Pratt. Quick turn on a PT-6 aircraft are nice in Beta or slightly reverse & less ear splitting whine.

They are slower to spool up, but both seemed to get the 8000 pounds off the water just fine. I'd like to know what the difference in gross weight & cruise is after the conversion? I sure wouldn't mind having either one & sticking to bigger lakes!

Paul Claus has a Garrett conversion on his Otter, no? I'm guessing he likes the rapid response with thrust. Sure seems to be able to massage that big machine into some tight spaces.

Garretts are noisy as hell, and DO sip fuel better than a P&W. Heat is an issue as mentioned above -- better enjoy standing out there "winding up the squirrels" after every shutdown... yes, people actually seem to believe that answer when they ask what on earth you're doing.

The PT-6 has that lag with the power levers but if you carry even a whopping TWO pounds above idle then you're not screwed when you need it.. NO lag, much less grey hair.

I love my P&Ws.

The lag in a PT6 has to do with the setup/installation not the engine. The Pilatus Porters use PT6s and have what's called the "STOL" cam installed on the FCU which provides instant response.

Jason