Anyone who has the Alaska Skycraft Fuel/Belly Pod or the Javelin Aux Fuel tank? Can you tell me where and how they are plumbed into the main system for a Carburetted engine (C180)?
Thanks

I have the Javelin baggage compartment aux tank in my 180 hp 170B. It is T'd into the fuel line from the right tank to the fuel selector above the right door. There is a check valve in the line from the transfer pump output to the T to keep fuel from transferring from the wing tank back into the aux tank do to gravity. Keep in mind that the 170 series has only one fuel outlet in each tank, though that should not make a difference. You burn the fuel out of the right tank, then switch to the left tank while refilling the right. Normally you would split the transfer. There is a warning not to over fill the tank. This would not have to be done with your 180. One of the limitations is that you are not allowed to operate off the right tank or both while transferring fuel and that the transfer pump is required to be off before selecting the right tank. The fuel transfer is at a rate of one gallon each two and one half minutes, forty minutes to transfer the full 17.5 gallons usable. The other limitation is that the baggage capacity is limited to 105 pounds with the tank empty and 0 pounds with the tank full. The full installation of the tank including pump and lines (flex hose) add 27 pounds to the aircraft empty weight. In the 170B with 18.5 gallon usable per wing it takes some planing and timing to transfer all of the fuel while still having enough fuel in the left tank to feel comfortable during the transfer into the right. One last thing, the fuel pickup in the aux tank is actually in the front of the tank even though the fitting is in the back. This means if you are tankering fuel and want to transfer on the ground in a tail wheel aircraft you will leave 2 to 3 gallons in the aux tank rather than the published 1/2 gallon. I hope this wasn't to confusing and understand that this is much more information than your question.

Tim

bat443 wrote:I have the Javelin baggage compartment aux tank in my 180 hp 170B. It is T'd into the fuel line from the right tank to the fuel selector above the right door. There is a check valve in the line from the transfer pump output to the T to keep fuel from transferring from the wing tank back into the aux tank do to gravity. Keep in mind that the 170 series has only one fuel outlet in each tank, though that should not make a difference. You burn the fuel out of the right tank, then switch to the left tank while refilling the right. Normally you would split the transfer. There is a warning not to over fill the tank. This would not have to be done with your 180. One of the limitations is that you are not allowed to operate off the right tank or both while transferring fuel and that the transfer pump is required to be off before selecting the right tank. The fuel transfer is at a rate of one gallon each two and one half minutes, forty minutes to transfer the full 18 gallons usable. The other limitation is that the baggage capacity is limited to 105 pounds with the tank empty and 0 pounds with the tank full. The full installation of the tank including pump and lines (flex hose) add 27 pounds to the aircraft empty weight. In the 170B with 18.5 gallon usable per wing it takes some planing and timing to transfer all of the fuel while still having enough fuel in the left tank to feel comfortable during the transfer into the right. One last thing, the fuel pickup in the aux tank is actually in the front of the tank even though the fitting is in the back. This means if you are tankering fuel and want to transfer on the ground in a tail wheel aircraft you will leave 2 to 3 gallons in the aux tank rather than the published 1/2 gallon. I hope this wasn't to confusing and understand that this is much more information than your question.

Tim

Great, Thanks Tim. Definitely not too much information. I am looking at putting a Turtlepac bladder in a Cessna cargo pod for a Trip NZ-Australia and back and want to know how to plum it in. If you have any drawings, STC info or 337 paperwork I would love copies to prove the viability of the system for ferry tank approval to our CAA. email [email protected]
I would also love to hear from anyone with the Alaska Skycraft setup?
Jamie

Don't fly towards the light Jamie! Too many Australian's over there

Battson wrote:Don't fly towards the light Jamie! Too many Australian's over there

I'll just fly around the Rock and come back.

Not exactly what you’re asking for, but the Flint tanks that are approved for Cessnas are plumbed in to the fuel system in the same manner that was discussed above: the fuel line from the tip tanks are connected via a T in the main fuel line from the wing tank in the wing root. Thus, you select the opposite wing tank to feed the engine, then energize the aux tank pump, which pushes fuel from the tip tank into the main wing tank.

You then alternate wings with this process till the tips are empty.

This system is approved by Flint on the 170, 180, 182, 185, and 206, at least. I’m pretty sure it’s also approved on the 210.

This is the simplest way to plumb extra fuel tanks in without major plumbing, followed by major documentation to the authorities. And it works.

MTV

JamieG. I will send you an email this afternoon with the Javelin information. The important thing to remember is that you are refilling a wing tank, not feeding the engine from the aux tank. Because of that there is no need to prove that the installation to meets certification fuel flow rates. It is important that the rate is higher than the rate at which the engine burns the fuel or you will run out of fuel before you can transfer enough into the tank you are not using.

Tim

mtv wrote:Not exactly what you’re asking for, but the Flint tanks that are approved for Cessnas are plumbed in to the fuel system in the same manner that was discussed above: the fuel line from the tip tanks are connected via a T in the main fuel line from the wing tank in the wing root. Thus, you select the opposite wing tank to feed the engine, then energize the aux tank pump, which pushes fuel from the tip tank into the main wing tank.

You then alternate wings with this process till the tips are empty.

This system is approved by Flint on the 170, 180, 182, 185, and 206, at least. I’m pretty sure it’s also approved on the 210.

This is the simplest way to plumb extra fuel tanks in without major plumbing, followed by major documentation to the authorities. And it works.

MTV

Thanks Mike, Yes it seems they were all plumbed this way. Makes sense. Tim has sent me the drawings for the Javelin.

JamieG, you haven't said how many gallons of aux fuel you are planning on but I speculate that it is a fairly long over water leg where a failure of the ability to transfer the fuel (pump or electrical failure) would result in an unplanned water landing. I am sure that you have thought of this. It may be worth considering installing two pumps, one plumbed into the right tank and one plumbed into the left tank. This would give you a backup pump plus the ability to transfer the total aux fuel earlier into the flight where enough range would be available to return or continue following an electrical failure. Since you are putting the tank in a pod rather than the baggage compartment it would be easier to make the connections to the fuel lines below the floor and route the lines through an inspection opening in the belly. You would still want to burn fuel from the tank you are not transferring to as the point is to not introduce an air bubble into the operating fuel stream if the aux tank runs dry. Sounds like a great adventure.

Tim

bat443 wrote:JamieG, you haven't said how many gallons of aux fuel you are planning on but I speculate that it is a fairly long over water leg where a failure of the ability to transfer the fuel (pump or electrical failure) would result in an unplanned water landing. I am sure that you have thought of this. It may be worth considering installing two pumps, one plumbed into the right tank and one plumbed into the left tank. This would give you a backup pump plus the ability to transfer the total aux fuel earlier into the flight where enough range would be available to return or continue following an electrical failure. Since you are putting the tank in a pod rather than the baggage compartment it would be easier to make the connections to the fuel lines below the floor and route the lines through an inspection opening in the belly. You would still want to burn fuel from the tank you are not transferring to as the point is to not introduce an air bubble into the operating fuel stream if the aux tank runs dry. Sounds like a great adventure.

Tim

Good thoughts Tim. I may just do that (have a back up pump). I do have two Islands as alternates, one of which I will have to refuel at anyway. I plan on a 42 gal bladder plus 80 usable in the main tanks, which is not enough to get all the way across. It can be done easily enough on standard tanks by refuelling at both islands, one of which is a bit of a dog leg though. I like the idea of lots of fuel and bypassing Norfolk if I want to. The Turtlepac is relatively inexpensive and simple and I like the idea of keeping the pod on for the trip, so I might as well fill it with fuel. Its costs 6 knots in speed which is 2.7 mins per hour, I can live with that. Also if I did have to put it in the drink, its a far better prospect with the pod on. That's all assuming we will have a open border with them by then.

bat443 wrote:.... You would still want to burn fuel from the tank you are not transferring to as the point is to not introduce an air bubble into the operating fuel stream if the aux tank runs dry. .....

This discussion, and esp this comment, brings to mind the recent forced landing into a river by one of the youtube guys in his Cub.

bat443 wrote:You would still want to burn fuel from the tank you are not transferring to as the point is to not introduce an air bubble into the operating fuel stream if the aux tank runs dry. Sounds like a great adventure.Tim

That's an interesting statement. I've always assumed (for lack of a better theory) that Flint specified that you not run the engine from the tank you're pumping to to avoid pressurizing the fuel system.

An air bubble could be a better reason, but I'm not sure.

One data point is that Maule uses a similar system to Flint, except their outboard and inboard fuel tanks are connected directly together, rather than at a T in the fuel line, as is done in Flint's system. In other words, the Maule tip tank pumps directly into that side main fuel tank, which then feeds the engine.

Maule says transfer both simultaneously, opposed to Flint, which says switch to the other main tank, then pump to the other tank.

There was a Maule accident that involved contaminated fuel which might have not happened if only one aux tank had been selected to pump to that main, but both pumps were activated, thus all tanks were contaminated. When I flew a Maule, I never transferred fuel from both tip tanks at once.

Interesting stuff.

MTV

Tim[/quote]
Great, Thanks Tim. Definitely not too much information. I am looking at putting a Turtlepac bladder in a Cessna cargo pod for a Trip NZ-Australia and back and want to know how to plum it in. If you have any drawings, STC info or 337 paperwork I would love copies to prove the viability of the system for ferry tank approval to our CAA. email [email protected]
I would also love to hear from anyone with the Alaska Skycraft setup?
Jamie[/quote]

Im sure you have read the Chichester account, I think its called Solo to Sydney. Big cojones.

daedaluscan wrote:Tim

Great, Thanks Tim. Definitely not too much information. I am looking at putting a Turtlepac bladder in a Cessna cargo pod for a Trip NZ-Australia and back and want to know how to plum it in. If you have any drawings, STC info or 337 paperwork I would love copies to prove the viability of the system for ferry tank approval to our CAA. email [email protected]
I would also love to hear from anyone with the Alaska Skycraft setup?
Jamie[/quote]

Im sure you have read the Chichester account, I think its called Solo to Sydney. Big cojones.[/quote]

Yes. No kidding. Deliberately dead reckoning to the Left of the island so that when he gets there he knows its on his right somewhere. GPS has changed the world.

In the Maule setup if an air bubble is introduced into the fuel, it just rises to the surface and joins the air in the tank. In the Flint, Javelin, Skycraft system the bubble gets carried down the fuel line with the fuel moving to the engine were it could result in vapor lock or a momentary interruption of fuel flow. The transfer pump will not pressurize the fuel system because the fuel line is open to the tank and the tank is vented. Even the 180/185 vents which have a check valve have a provision to vent positive pressure, just not fuel.

Tim

hotrod180 wrote:

bat443 wrote:.... You would still want to burn fuel from the tank you are not transferring to as the point is to not introduce an air bubble into the operating fuel stream if the aux tank runs dry. .....

This discussion, and esp this comment, brings to mind the recent forced landing into a river by one of the youtube guys in his Cub.

https://youtu.be/QJrVUZKcxrU

bat443 wrote:In the Maule setup if an air bubble is introduced into the fuel, it just rises to the surface and joins the air in the tank. In the Flint, Javelin, Skycraft system the bubble gets carried down the fuel line with the fuel moving to the engine were it could result in vapor lock or a momentary interruption of fuel flow. The transfer pump will not pressurize the fuel system because the fuel line is open to the tank and the tank is vented. Even the 180/185 vents which have a check valve have a provision to vent positive pressure, just not fuel.

Tim

I can understand the reason for not feeding from the same tank as you are filling. You have no idea when the auxiliary is empty and pumping air. That air will rise and vent in the tank you are transferring to if so long as you are not feeding to the engine from that same tank? Correct Tim?

Deleted double post

Correct.

Aryana wrote:

hotrod180 wrote:

bat443 wrote:.... You would still want to burn fuel from the tank you are not transferring to as the point is to not introduce an air bubble into the operating fuel stream if the aux tank runs dry. .....

This discussion, and esp this comment, brings to mind the recent forced landing into a river by one of the youtube guys in his Cub.

https://youtu.be/QJrVUZKcxrU

Ouch, but good video.