sumping an amphib tank (sea rey)

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mcurcio1989

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I'm building an Aventura which isn't a sea rey but basically it's less common twin. With the tank being low in the boat hull my understanding is that most operate without a sump due to the difficulty involved with that physical geometry. Has anyone come up with a reasonable way of sumping fuel? do people add water seperators or just fly with a pocketful of dry hope?
 

Riggerrob

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Sea King helicopters have a row of drain bolts along the keel. Their primary function is to drain water out of the hull
after water landings. The bolts are made of nylon ( to reduce corrosion) and are attached with little strings (to prevent loss). They screw into nylon nuts that are permanently attached to the keel. Drain holes are drilled all the way through the aliminium keel.

I cannot remember what we used to drain water out of Sea King fuel bladders.

May I suggest that you install a brass fuel drain plug behind the hydrodynamic step?
 

Himat

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I'm building an Aventura which isn't a sea rey but basically it's less common twin. With the tank being low in the boat hull my understanding is that most operate without a sump due to the difficulty involved with that physical geometry. Has anyone come up with a reasonable way of sumping fuel? do people add water seperators or just fly with a pocketful of dry hope?
Two questions on what you want to achieve:
- Do you want to make a sump to collect and drain water from if the fuel get contaminated?
- Do you want to make a sump to collect fuel in to pick up the fuel from?
 

mcurcio1989

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^^ That is what I'm thinking.

^I'm talking about sampling as part of preflight not for draining large quantities.

My primary concern here is for preflight checking for water in the fuel. I thought about adding a plug at the step (and I may for draining water like in a boat -since the bilge can't get all of it) but it doesn't seem like it would be practical for during preflight. If I'm operating from the water I can't check for contaminated fuel and it is not easy to crawl under the step on the land anyways.

After finding a manual for some sea reys it sounds like some of them have a fitting in the bottom of the tank with a 1/4 turn valve and then a primer bulb pump (like what you have on an outboard. so you pump fuel up into a clear container and then check for water. This will have to be a larger container than your normal sampling cup, to get everything through the line. I will size it appropriately and in this case the fuel will probably go back in, due to the quantity, instead of being weed killer (assuming it looks good)
 

Himat

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^^ That is what I'm thinking.

^I'm talking about sampling as part of preflight not for draining large quantities.

My primary concern here is for preflight checking for water in the fuel. I thought about adding a plug at the step (and I may for draining water like in a boat -since the bilge can't get all of it) but it doesn't seem like it would be practical for during preflight. If I'm operating from the water I can't check for contaminated fuel and it is not easy to crawl under the step on the land anyways.

After finding a manual for some sea reys it sounds like some of them have a fitting in the bottom of the tank with a 1/4 turn valve and then a primer bulb pump (like what you have on an outboard. so you pump fuel up into a clear container and then check for water. This will have to be a larger container than your normal sampling cup, to get everything through the line. I will size it appropriately and in this case the fuel will probably go back in, due to the quantity, instead of being weed killer (assuming it looks good)
To check the fuel for water and other contamination as part of the pre flight it sounds like you have found the solution. Have some kind of fitting or tube that reaches the lowest point in the tank and pump a sample into a clear container. Let the sample settle and if all is good put the fuel back into the tank.
 
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