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Posted on August 16, 2001 at 02:01:46 AM by cydoniaquest

I was wondering: Have you ever heard of modular tanks being designed for Boeing's cargo plane models…..(not to say that Boeing would necessarily have to be involved in the design)?

Now the way these tanks would work, is that they might fit to the shape of the fuselage (like a FedEx container…although this is not totally necessary) These would possibly have a low center of gravity, so the sloshing of liquid inside would not create a problem for a/c weight and balance. Most likely these modular tanks would also use internal baffles (to dampen internal fluid movement inertia). They would be able to fit through the cargo bay door and rolled into place on the roller platforms. They would also fit into ordinary tractor-trailer rigs so they could be transported by virtually any trucking company (with pneumatic roller equipped trailers).

Inside the aircraft, the tanks could be pressurized and connected by a series of hoses with simple ring/bayonet type connectors, and in this way, the whole system of tanks could feed to pre-installed plumbing within the aircraft.

These could be transported and loaded full, to preclude any requirement for tanker type vehicles to replenish chemical supply once the system was onboard the aircraft , and thereby eliminate suspicious looking activity. When a modular tank is empty it would simply be detached from the hoses, and taken out of the aircraft entirely (as a unit) , and hauled away by a truck to be refilled at a remote location.

Using this method, there would be no need for any special airport equipment that doesn't already exist for all cargo companies. The transportation of these tanks would be totally discrete using ordinary tractor/trailer rigs. Once the aircraft had completed a spray mission, the same aircraft could then continue with other ordinary cargo missions.

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Posted on August 16, 2001 at 11:47:40 AM by duncankunz

...Cy, it would be feasible from an engineering point of view to develop palletized tanks that could be inserted into various aircraft and connected to pre-determined ports for spray missions. However (and this is just off the top of my head), there would be several engineering and aerodynamic considerations that would make such a move more challenging that one would first think.

First, although baffling or high-porosity rigid foam in the tanks could minimize sloshing, the fact that the tank's (and thus the aircraft's) weight would change as the contents were being sprayed would require some VERY involved dynamic weight-and-balance calculations during flight. Of course, this is already done (because the aircraft loses weight as it burns its fuel), but the aircraft is designed with the fuel tanks placed in such a way that weight-and-balance calculations and changes are minimized. Placing a changeable-weight cargo where the aircraft is 'expecting' constant-weight cargo would require some major changes to the flight management software; probably something based on existing FMS for an aerial tanker. I believe that REAL pilots (as opposed to someone with a total of 50 hours in a Cessna 172) could answer that question better than I could, though!

Second, the engineering advantage of a modular tank arrangement is based on a one-size-fits-all approach. This wouldn't work well for two reasons. (1) Different aircraft have different cargo configurations. When you look at the "big five" aircraft used for cargo-hauling flying today (Boeing 747, McDonnell-Douglas MD-11, Lockheed L1011, Lockheed C-5B, and Airbus Industrie A340), you'll notice that they're all different in the way their internal compartments are configured. A tank designed for one might not fit into another.

Now it's true that you can use the "least common denominator" approach, which is what the military and civil cargo haulers do with standardized pallets. But there is another problem. Since the aircraft are shaped differently, you probably wouldn't be able to install spray-ports in the same place on all the planes. The aerodynamics of one fuselage might be okay for a particular placement, but it wouldn't work efficiently on another fuselage. Not only that, but fuselage X might have a series of hydraulic lines running through the same place where a spray-port on fuselage Y is. This means that the mating holes on the palletized tanks would not necessarily match up with ALL the ports on ALL the planes.

Is this a show-stopper? Not necessarily. But it does mean that the engineering problems are still going to be pretty daunting, no matter what approach you choose.

Regards,

Duncan

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Posted on August 16, 2001 at 07:04:43 PM by cydoniaquest

Thank you, Duncan for your kind, intelligent response (I knew I could count on you for that). I think it is unwise to give out your phone number though, given the type of e-mail harassment Deb says she is getting....but I'm sure you've thought that through!

I don't see this as big of an engineering problem as you do however. First, we could use simple weight and balance calculations for both the full weight and empty weights of the tanks. If both weights are within the CG envelope, then we simply dispense the liquid from the tanks equally....and there should be only negligible CG shift.

Remember, even thought the weight of this cargo is changing it is the only cargo we are going to have manage on this particular flight. I have not dealt with FMS (Flight Management System) software, since the biggest aircraft I've flown was a Beechcraft Duchess and Piper Seminole, but the physics are very simple mass times lever-arm calculations for which every POH (pilot's operating hand book) will have a chart. We simply find the empty weights of these tanks and see where we can load them within the aircraft CG (Center of Gravity) limits.....then we find the area where we can load full tanks within CG limits. The area where both empty and full weights overlap and are within limits, will be were we place the tanks. We therefore know the range of weights in between the empty weights and full weights will also be within limits so long as the tanks drain equally. Not a tough calculation. We could even mark off the area were the tanks are to be loaded....and use that as a constant, since the tanks would be made to uniform specifications. In fact this calculation would only need to be done once for each type of aircraft, given that the weights of the tanks and the chemical used remain the same.

As for the plumbing, well....the tanks could feed into a manifold hose that would empty into a distribution tank requiring only one hose to exit the fuselage for each wing (In other words only two holes on each side of the cabin. There should be enough room through the wing spar holes to the engine mounts to run maybe a 1/4 to [1/2--typo corrected by 3T3L1] inch diameter hose. If we also incorporate my high bypass engine spray design, the spray jets shouldn't be a problem, and the bypass air would actually act as a low pressure area to suck the chemical out the spray ring nozzles.

The internal aircraft cargo compartments shouldn't present much of a problem for tank design either, I wouldn't design these tanks to the ceiling (if that's what you're thinking). I would make them relatively flat rectangular shaped (much longer and wider than they are high)....the side of the tank may not need to conform to the fuselage since they might not even need to take up the entire width of the fuselage. I would think that the fit of the tanks would be one of the easiest problems to solve, as it would not be difficult to make a shape that could conform and be used universally in virtually any model of aircraft.

I'll draw up a simple tank design and scan it to present the idea in more detail.

By the way, I’d welcome some input from any aircraft engineers, or hydraulic engineers reading this who might also have some input on this design idea....the areas that I think would reqire the most attention are the holes drilled into the fuselage for each hose. It seems to me, these holes would require special reinforcement and sealing. I don't know, but there may even be existing vents that could be used to run the hoses out to the wings.

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Posted on August 17, 2001 at 03:05:56 AM by cydoniaquest

Wow 3T3, I didn't realize you were copying these posts at Mark's...but since you are, I might as well respond to my own comments here since I'm banned (by self request) at Chemtrail Central.

As you can see, I was in a bit of a hurry on my last post to Duncan, so there were a few typos. To clarify some things, I didn't mean to say up to a 12 inch diameter hose (run out to the wings)....I meant to say 1/2 inch....but the actual diameter would depend on the desired flow rate...and it might help to get input from a hydraulic engineer for this information.....I can't imagine it would need to be much bigger than 1/2 inch diameter though.

Also...when I say "run hose out to the wings", I mean internally through the wing spars. These spars (that the external skin of the wing bolts to), have holes in them where metal is removed for weight savings, so plumbing can be run through these holes in the spars (as it already is). This chem-hose would run inside the wing down to the engine mounts where other plumbing such as fuel lines and wiring is also run internally.

Duncan sites a problem that the wing tanks wouldn't line up with holes in the cabin walls which allows the hose for each tank to exit the cabin to the wings....but I think he misunderstood the design idea a little bit (since I really haven't comprehensively presented it yet). The way I see it working, is that each tank would be tied into a larger hose running through the center of the cabin area, so all the liquid from each tank exited equally into a single larger hose (which acts sort of like a manifold). This hose, in turn, would empty into a small distribution tank which allowed the chemical to flow equally into the two hoses that go to each wing. (This will be easier to show by drawing later, if there is an interest)....

Maybe I'll work on that over the weekend...and if anybody can improve on this design, feel free to add to it (not that we want to give anybody any ideas)...but my intention was to just prove to the skeptics that not only could this be done, but it could be done feasibly, economically and efficiently using ordinary cargo jets.

If a spray program was occurring, this would account for why people see so many different models of aircraft, given that there is a cargo version for just about every model. These jets could contract with the military and when the spray mission is over, still be used for ordinary cargo transportation.

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Posted on August 19, 2001 at 08:29:49 PM by LTC8K6

A 747-400 freighter can carry 244,000# max. 1 cubic foot of water weighs 62.427#. This limits you to approx 3,908 cubic feet of water(244,000/62.427=3,908.56)or 29,239 gallons. That is a mostly empty 747-400, since it's payload volume is around 27,450 cubic feet.

For a C-17 it's 2,787 cubic feet of water versus it's 20,900 cubic foot capacity, or 20,850 gallons.

You wouldn't get too many palletized containers full of water on board either plane.

If you tried to fill up the 747-400 with palletized containers full of water, they would weigh over 1.5 million pounds!

I used the highest capacities I could find for each airplane.

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Posted on August 20, 2001 at 12:06:39 AM by LTC8K6
The KC-130 Hercules Tanker is equipped with a removable 3600 gallon (136.26 hectoliter) stainless steel fuel tank that is carried inside the cargo compartment providing additional fuel when required.

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Maybe you could make use of these, Cy....
Posted on August 20, 2001 at 12:33:41 AM by LTC8K6
http://www.udshipping.com/flexi.htm

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Originally posted by NaiveNoMore:
. . .

Considering that the weight of jet fuel (you pick the type) is considerably heavier than water, the type and size of these bladders do vary by aircraft type and configuration. End result; the capability does exist.

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