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3 tanks in series?

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Old 02-13-2013, 02:57 AM
  #1
rossi63
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Default 3 tanks in series?

In what order do I connect 3 tanks? Both my Viper and F-16 have two tanks on cg and one in front. The manuals for both models shows that its tanks on cg is drained first before the tank in front. Balance the model cg with a half full front tank is ok as long as you know when the level is reached and land with perfect cg. Would it not been better to balance the model with empty front tank and drain front tank first so remaining 2/3 of the trip flown with perfect cg? If you want to land earlier it's only the first minutes model is front heavy.

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Old 02-13-2013, 04:14 AM
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Canadian Man
 
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Default RE: 3 tanks in series?

Yes your idea is correct.

Both ways will work but I would drain the tank that is ahead of the CG first.
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Old 02-13-2013, 05:42 AM
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Gary Jefferson
 
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Default RE: 3 tanks in series?

The typical setup is to run the main tanks in parallel and then run a single line to the front tank (in front of the C.G.), then a line out of this tank to the UAT. I have run this configuration in many different types of air frames and never noticed any issues with C.G.
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Old 02-13-2013, 05:51 AM
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David Jackson
 
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Default RE: 3 tanks in series?


Quote:
ORIGINAL: Gary Jefferson

The typical setup is to run the main tanks in parallel and then run a single line to the front tank (in front of the C.G.), then a line out of this tank to the UAT. I have run this configuration in many different types of air frames and never noticed any issues with C.G.
I ran the same tank configuration on a 1/6 scale F-16 with no issues
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Old 02-13-2013, 05:58 AM
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essyou35
 
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Default RE: 3 tanks in series?

I usually run my two rear tanks in parrellel, front tank empties last. This is to ensure the CG dont shift too far back. On my setup I barely ever touch the front tank as I only fly 6 mins then land.

3 tanks in series is a lot of pressure during fueling and make sure you use the largest fuel line you can.
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Old 02-13-2013, 06:09 AM
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Gary Jefferson
 
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Default RE: 3 tanks in series?

Using 3 tanks in series really doesn't make much sense because you then have one main tank empty on one side of the plane. I know the tanks are close to the C.G. but I am not sure that is a good idea.
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Old 02-13-2013, 09:38 AM
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Default RE: 3 tanks in series?


Quote:
ORIGINAL: Gary Jefferson

Using 3 tanks in series really doesn't make much sense because you then have one main tank empty on one side of the plane. I know the tanks are close to the C.G. but I am not sure that is a good idea.
Doesnt matter at all. Lateral balance of a plane makes very little difference. The bites in the fuz are so close to the centre line it will make no difference

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Old 02-13-2013, 09:41 AM
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Default RE: 3 tanks in series?

3 in series seems a lot. Perhaps the best solution is a combination of the two solutions: to drain front first and then remaining two in parallel?
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Old 02-13-2013, 09:55 AM
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rossi63
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Default RE: 3 tanks in series?


What if I balance the model with empty front tank and parallel connecting tanks in cg?


Front tank.



Tanks on CG


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Old 02-13-2013, 10:52 AM
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Default RE: 3 tanks in series?

The typical way is to have the main tank supply the UAT and the two saddle tanks supply the main tank either in series or paralell.

Balance the plane with tanks empty and UAT full. The idea is that you will drain the saddle tanks first and therefore no change in CG. Then as you empty the main tank you will get a shift in CG. Since you will rarely empty the main tank (usually land with some fuel in main tank) the CG shift will be slight. If you find that you are flying and usually have a forward CG due to residual fuel, you can move the CG back a little. Just be cautious because the one time you do run the main tank down low, you will have an aft CG.
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Old 02-13-2013, 02:45 PM
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Default RE: 3 tanks in series?

You are worrying about this too much
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Old 02-13-2013, 08:58 PM
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Default RE: 3 tanks in series?


Quote:
ORIGINAL: JimJones1

You are worrying about this too much
Yuuuuuuuuup
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