Otter tanks

[MooChooser 0]

Does anyone know why the otter doesnt have wing tanks?

[JohnRich 4]

Because it has enough room in the belly?

[diablopilot 2]

Some do, if they've got the long range kit.

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You're not as good as you think you are. Seriously.

[pchapman 279]

I don't know for sure but my vague suspicions are:

High wing plus bush plane origins; harder to hand pump fuel into the wings.

(Not that ladders weren't needed anyway, if only to deice the wings & tail ...)

The single Otter and Beaver had fuselage tanks too (didn't they?) so there's precedent from the company's earlier products.

Not sure if a newly certified plane under FAR 23 or whatever would normally be allowed fuselage tanks any more -- there may be more emphasis on getting the fuel away from the cabin, no matter what disadvantages may occur too. (The Twin Otter was certified under the old CAR 3 preceding FAR 23.)

[vpjr 18]

If you are in the Bush and trying to fuel a high wing plane out of 55 gal drums you would have to work harder hand pumping the fuel to that height. I used to know the math. The belly tanks limit how high you have to raise the fuel. Less work. Boost pumps in the tanks do the rest of the work to the engines.

[totter 2]

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High wing plus bush plane origins; harder to hand pump fuel into the wings

The Twin Otter wing tanks are pressure refuelled. There are no Fuel Fillers on the wings.

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The single Otter and Beaver had fuselage tanks too

Yes. The Beaver can also be equipped with wing tip tanks that have to be filled on the wing and then are gravity drained to the forward fuselage tank.
The Single Otter never was equipped with wing tanks.

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Not sure if a newly certified plane under FAR 23 or whatever would normally be allowed fuselage tanks any more

The DHC-6-400 still maintains the fuselage tanks and this aircraft is certified under the current provisions of Part 23.

[diverdriver 5]

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High wing plus bush plane origins; harder to hand pump fuel into the wings

The Twin Otter wing tanks are pressure refuelled. There are no Fuel Fillers on the wings.

There might be some twin otters with single point refueling (which would be pressure refuelled) but most are definitely not pressure refueled.

And there are long range tanks that are fueled over the top of the wing.

Chris Schindler
www.diverdriver.com
ATP/D-19012
FB #4125

[riggerrob 643]

" ... (Not that ladders weren't needed ..."

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Ladders are amusing on ski-planes and are an hilarious on float planes!

[totter 2]

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There might be some twin otters with single point refueling (which would be pressure refuelled) but most are definitely not pressure refueled.

And there are long range tanks that are fueled over the top of the wing.

Chris,
You need to refresh yourself on the Wing Tank System of the Twin Otter by reading Supplement 8 to the AFM.
There are two ways to fuel the wings.
The first is Over The Wing using the filler neck on each tank.
The second way is to "Pressure Fuel" the wing tanks using the Boost Pumps in each collector cell. This is not Single Point re-fuelling. You actually fill either the Forward or Aft fuselage tank. Fwd supplies the RH Wing, Aft supplies the LH Wing. With boost pumps on you select Re-fuel on the appropriate 3-position wing tank switch. This OPENS the re-fuelling valve, at the wing tank, allowing fuel to flow INTO the wing tank from the collector cell. You watch the qnty gauge to know when its full. No need to use a ladder to fuel the wing.
I missed stating "No Fuel Fillers on the wing" in my original post. Should have read "No need to use the fuel fillers on the wing"

[diablopilot 2]

Not in disagreement with what you've stated, but there are some Otters out there equipped with Single Point.

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You're not as good as you think you are. Seriously.

[totter 2]

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but there are some Otters out there equipped with Single Point.

If there are then it probably would be a military conversion. I've never heard of any.

deHavilland never offered Single Point re-fuelling, (not even as an S.O.O.), on any of the variants. This includes the -100, 200, 210, 300, 310 & 320.
Viking is not offering it, even as an option, on the -400.
There are no STCs either.

[diablopilot 2]

Pretty sure there is one sitting down at Perris, N708PV to the best of my recollection had a SPF system installed, and I seem to remember a conversation about it having had it for it's use in Hawaii as a commuter.

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You're not as good as you think you are. Seriously.

[diverdriver 5]

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There might be some twin otters with single point refueling (which would be pressure refuelled) but most are definitely not pressure refueled.

And there are long range tanks that are fueled over the top of the wing.

Chris,
You need to refresh yourself on the Wing Tank System of the Twin Otter by reading Supplement 8 to the AFM.

........

I missed stating "No Fuel Fillers on the wing" in my original post. Should have read "No need to use the fuel fillers on the wing"

Ah. That's where I got misremembered.

Chris Schindler
www.diverdriver.com
ATP/D-19012
FB #4125

[totter 2]

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Ah. That's where I got misremembered.

Sorry about that. Brain moving faster than fingers.

[MooChooser 0]

Thanks for the replies