Fuel Transfer to One Side

[Kyle Sanders]

Hello, I seem to have an isolated problem.

Whenever I start up (like i always have since V1.1) from Cold and Dark

Everything goes well, FMC INIT, START UP PROCEDURES, PUSH BACK the whole works.

When I apply throttle in order to start taxi, all fuel starts to push from the left tank to the right (i have had it go from the right tank to the left this last time).

My correction for this is to sit, and do a manual override xflow of fuel. This takes an unreasonable amount of time to even it back out. The Ground Controller starts asking questions EVERYTIME....

Once it is even, i cut the manual override off and then from there on, everything is good to go.

I have talked to two other JROLLON CRJ200 operators and they do not experience this. I would say that it is pilot error but this did not start until about V1.3...

This is the checklist that i have made for myself (referenced from the provided manuals and checklist): https://docs.google.com/open?id=0B5EvMiai4QocSVVweTA3cHRRbUdaaUwyaGw2SVI4dw

Please tell me what i am doing wrong?

Thank you.

[Japo32]

As in the other post, I think you didn't read the full manual. If so, please read it, because all is explained..

But I would say that there are two xfeed ways.. One is the gravitatory one that takes long time.. and the other the electrical pump way. Which takes less.

All explained in the manual.

[Kyle Sanders]

The two ways you describe to transfer the fuel is fine, i understand how to do that.

My problem is that it is EVENLY DISTRIBUTED when i start up my engines.

Exactly when i apply throttle to start to taxi, THEN the fuel starts to transfer to only one side.

I have to stop the aircraft, and use the ELECTRICAL PUMP to get the fuel back over to its' side.

Once i have done this, then the aircraft acts fine.

Edited March 25, 2012 by Kyle

[Japo32]

Mmm ... page 48 of manual:

Fuell Storage:

Is composed of two main wing tanks and one center tank. In flight, as the wing tank fuel quantity decreases, the fuel system computer will automatically transfer fuel from the center tank to the wing tanks to maintain lateral balance.

So if there is a not center balance, it will start automatically to put the extra fuel from one tank to another as described.

[Kyle Sanders]

OK, yes i understand this as well...

But when i apply throttle for taxi, it is already balanced

it does not take from the center tank, it takes from one wing tank and puts it ALL in the other tank

Then my aircraft starts to lean to one side because it is so heavy.

[Japo32]

Don't know.. lets see what philipp has to say.. but I have just tested in 1.4.5 (maybe it is a 1.4.4 bug.. but you are the only one reporting) I tested.. and normal situations from cold and tark.. taxi... I can make only transfer from one tank to another by pressing the gravity xflow or override one..

If I put fuel in the central tank it will fill the wings tanks to maintain the wings the heavy possible all time.. if I put more in one wing tank.. it will start to fill the other until have same ammount and then start to burn both wings same time..... Normal situation.. don't see any extrange here.

[Kyle Sanders]

Ok,

When i fill my tanks, i use the TOTAL FUEL slider... should i use only the CENTER TANK slider?

I do not believe it is a 1.4.4 bug because it was doing this to me in 1.2 1.3 and now 1.4.

Sense i am the only one reporting it... i have made a checklist of what i do step-by-step. Could you please look it over and see if i am doing something wrong please?

https://docs.google....aaUwyaGw2SVI4dw

Additionally... here is a screen recording and sound of what is going on. http://www.youtube.com/watch?v=265sr9Tgwv8&feature=youtu.be

Edited March 26, 2012 by Kyle

[philipp]

Hi Kyle,

you have Gravity XFLOW open when you start to taxi. That's nothing you would do under normal operating conditions.

snippet from the CRJ-200 FCOM page 13-30-2

If the powered crossflow system fails, the flight crew can select the GRAVITY XFLOW switchlight on the Fuel Control Panel. This will open the gravity shutoff valve to allow fuel transfer by gravity between wing tanks. Gravity crossflow can also be enhanced by using a sideslip maneuver.

So here is what happens to you: Because the gravity xflow valve is open, I calculate the flow from one tank to the other based on the sideslip angle. When taxiing on ground, side-slip angles become HUGE, because you can't counter the centripetal force with gravity, because you have no roll (aileron) on ground (i hope you taxi with all three gears firmly on the ground )

Simple solution: Don't use gravity crossflow on the ground.

Philipp

[Kyle Sanders]

Hi Kyle,

you have Gravity XFLOW open when you start to taxi. That's nothing you would do under normal operating conditions.

snippet from the CRJ-200 FCOM page 13-30-2

Simple solution: Don't use gravity crossflow on the ground.

Philipp

Wow, i did not know this. I will try it out and post what happens... i do thank all of you for your dedicated help throughout my problem here.

[Kyle Sanders]

.....Simple solution: Don't use gravity crossflow on the ground......

Philipp

I want you to know that this worked. I feel so stupid now lol

[jagipson]

For what it's worth, I had this problem, but I didn't recognize it as a bug. I right after takeoff, the plane was listing to one side and after trimming it out, I happened to notice the fuel balance problem. I don't remember exactly what I did, but I DID turn of Gravity X-FEED and activated one of the two fuel pumps and things slowly evened out. If I recall, the checklist has you turn ON the gravity X-FEED when starting, and turn it OFF at lineup. Is this is true, then the checklist might need to be revised.

[Kyle Sanders]

Is this is true, then the checklist might need to be revised.

Actually this is a very old post. I have fixed the problem. I was opening the XFLOW and taxiing... that shot all the fuel very easily to one side. So i do not open the Flow at all now. I have talked to real CRJ pilots and have revised the checklist. It is attached to this message here. I hope you find it useful

Edited September 26, 2012 by Kyle