Single Otter Float Drivers

[sheephunter]

Can you tell me what your useful (I know ea. aircraft is differrent) load would be for an 85 mile trip + 85 return. How many pounds of crap will you let me load in for each leg. Thanks.

[phillyfan]

About 2000 for the way out and about 2200 for the way back. That's for a PT6 Otter on Amphibs.

[sheephunter]

Phillyfan, thanks but was looking for the old school, P&W R-1340 on straight floats. Or let me know what the fuel burn is and I think the empty is around 5300 +/- and gross is 8000. Do these numbers sound right or even close. Just trying to figure out how many trips I need. Oh, your machine sure would be nice to be working with.

[phillyfan]

We use to aim for about 1800lbs on a 75nm trip in the piston Otter. So I would imagine your numbers should be pretty close to that. I think we use to plan for a fuel burn of around 30gal an hour.
Your weights are correct.

[sheephunter]

Phillyfan, thanks for the info.

[Matthew]

How big's the lake............

kidding. 1800 is about right.

Matt.

[1000 HP]

With the Walter Turbo-Otter on straight floats (Empty weight 4866), you can haul 2522 pounds out and about 2750 pounds back on an 85 mile trip, with the 30 minute reserve. It's a great hauler but a little low on power....

[phillyfan]

Hey 1000hp. Sounds like were getting the Garrett Otter here this winter. At first I kinda preferred the Walter over the Pratt, but I think the Pratt is kinda growing on me a bit. Now i'll have to get use too a new engine again.

[turboguy]

The Pratt's ok...as long as you don't mind your flaps restricted to half travel and your VNE restricted to 133 MPH.

[1000 HP]

Hey 1000hp. Sounds like were getting the Garrett Otter here this winter. At first I kinda preferred the Walter over the Pratt, but I think the Pratt is kinda growing on me a bit. Now i'll have to get use too a new engine again.

Let me know if you need a driver, I NEED more power

[Level@3000]

I should know the answer to this, but why is the speed restricted to 133 with a Pratt but not with the Garrett? Is this accurate? Is it just an approval thing?

[lupin]

I imagine the speed restriction is applicable to both conversions. The Otter tail is held together with #3 rivets.... quite flimsy. I doubt an different engine would have an impact on a speed limitation.

Éric

[twotter]

It's just the way it was certified.. Much like the flap restrictions with the Vazar kit.. When you do the Harbour Air upgross you get to use more flap again.. You still don't get it all but you do get more...

[1000 HP]

My thoughts are that the decreased flap is because of the reverse. The max flap extension on the otter is 94 mph. They are weaker flaps than the Beaver. Perhaps the full reverse would damage the Old Full Flaps..

[sdp]

why would reverse hurt the full flaps? on the garrett no more then 10 for take off(anymore will just slow you down) as soon as you are flying get rid of the flaps and climb @ about 100mph for 1500+fpm @ 8367. landing there is deffinetly no need for lots of flap, pull the power past the gate and your as slow as you want to be. i have never used the 30 degrees I use mabe 20 once or twice, 10degrees 99% of the time.

[LLLDRAM]

Been a few years since I've had my nose in the Garrett POH however I do re-call for the most part that it refers to the original DHC3 POH and that it must be operated within the parameters stated ie; 144 wheels/133 floats. There is nothing other than this to my recollection in the Garrett supplement related to VNE. The Pratt supplement does however re-quote this VNE provision.

Reason being as explained to me for the partial flap on the PT6 is the delayed power curve, the Garrett has no such delay curve. I can understand the concept having a few years on both......not too desireable to be coming in heavy and slow, full flap and a 6 - 8 second power delay encountering dead air.......yur gonna "smack" no matter how far you push that "go" lever Not that any of us normally seek such a situation but these -T approvals and subsequent supplements are drafted in effort to protect even those that tempt.

FWIW - the Garrett is by far the superior conversion......

[Unusual Attitude]

The 9000lb gross weight mod that Harbour Air developed has increased the amount of flap available over the Vazar conversion but not to the full range of the piston Otter.

[jamesbay]

So, how does Harbour Air increasing their gross weight to 9000 warrant more flap travel if the lag in power compared to a garret was the reason for less flap in the first place? IE: more weight, slow and dirty = harder pancake.

[LLLDRAM]

So, how does Harbour Air increasing their gross weight to 9000 warrant more flap travel if the lag in power compared to a garret was the reason for less flap in the first place? IE: more weight, slow and dirty = harder pancake.

Close to being correct on the wording

The initial comparison or flap restriction, wasn't in relation to the Garret, it was to the PT6 compared to the original 1340 which the latter, obviously had the juice immediately when you wanted it. Remember, the PT6 was one of the first conversions to set the bar so to speak.

As I'm told, given the instantaneous response on the direct drive Garret and no lag in spool up, it was deemed comparable albeit highly more powered than the 1340 so no flap restriction was required.

As for Harbour Air at 9000, can't help you there....

LLL

[LLLDRAM]

PS:

There does exist Garret conversions at 9000 with no flap restrictions fwiw.

[BJ Titsengolf]

LLLDRAM,
your user name is familiar, I used to fly an Otter with that LLL reg and it was owned by Dram....coincidence?

[LLLDRAM]

there are no coincidences check yur pms.

LLL