Potential F4u-1a fule management bug?

[DaddyAce]

I've been flying the F4u1a some lately after a long break from it.  As I recall the auto fuel mode used to drain wing tanks first, now it seems like it starts that way, but quickly switched to the main tank.

[FLS]

Did they drain first or just go empty first in their turn because they were smaller?

[DaddyAce]

Did they drain first or just go empty first in their turn because they were smaller?

....based on what I recall from some years ago I expected was that the wing tanks would drain first, but now it seems one wing tank starts, then quickly switches to the Main, so when I notice I manually select the wing tanks to drain them first, because the auto feature seems to want to drain the main tank first.    Those wing tanks go pretty quickly so I sometimes forget and then the engine starves out during a fight and I have to manually select another tank.  I may not have the details exactly right, but I keep noticing that if I don't manually select which tank to drain it automatically drains down my main tank before the wing tanks.

[FLS]

IIRC it should be switching between wing tanks and main tanks until the wing tanks are dry. The exception being drop tanks which empty first.

I find it hard to believe there's a real advantage to draining wing tanks first.  I know it has it's fans but I haven't seen any performance data to support it. 

The disadvantage is getting a main fuel leak with empty wing tanks.

[DaddyAce]

Okay, that makes sense.  I read a post years ago that advocated draining the wings first and leaving some to counterbalance torque, as I recall in the rh wing tank, and this also left some reserve.  I think I'll just try going with the auto fuel feature for now and see how that goes.  Thanks for the input FLS!   

[FLS]

 

[SAJ73]

It has always been like that, it constantly shifts between wingtanks and main when in auto mode.

What you probably remember is a discussion about the possible advantages of selecting tanks manually, and that some choose to drain wingtanks first. Main advantages would be better balance and faster torquerolls and snaprolls when in a fight. But most pilots would not notice that much of a difference. 


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[DaddyAce]

Yes, I think this may be the case, and in part at least of why I stated it as "potential.  I've flown a few sorties today leaving the fuel tanks set to auto-select.   I have not noticed fuel being drawn from anything but the main so far, but don't think I've lasted beyond perhaps a half-main tank full, and have not been checking all the time.  But I've also noticed that if I select for a partial fuel load, it seems to prioritize a full main tank first.  Thanks for your input!   

[DaddyAce]

Flew a sortie today where I just about completely drained the main tank.  It never did switch to draw from the the wings.  It looks like the auto mode is more or less set to use the wing tanks as reserve.

[SAJ73]

Flew a sortie today where I just about completely drained the main tank.  It never did switch to draw from the the wings.  It looks like the auto mode is more or less set to use the wing tanks as reserve.

Then there must have been a change afterall, because it used to cycle between main/L/R/Aft before. I have not looked at it lately myself, but if it drains the main tank completely first there has definitely been changes made.


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[hgtonyvi]

At 50% fuel there is no wing tanks. At 75% you will have to switch to wing tanks manually and drain them if you want. I usually keep my wing tanks just incase i get my main tank shot. In most cases the main tank will leak...its up to the pilot to decide overall how he will be fighting.

[DaddyAce]

Then there must have been a change afterall, because it used to cycle between main/L/R/Aft before. I have not looked at it lately myself, but if it drains the main tank completely first there has definitely been changes made.

Yes, I thought it used to do something more like this, hence my post.

[DaddyAce]

At 50% fuel there is no wing tanks. At 75% you will have to switch to wing tanks manually and drain them if you want. I usually keep my wing tanks just incase i get my main tank shot. In most cases the main tank will leak...its up to the pilot to decide overall how he will be fighting.

Rude, I've been generally running 100%.  But given how it's currently set up, and considering comments from you and FLS, I'm inclined to run it as you say.  I've had the engine cut out in fights a couple of times when I had manually selected a wing tank......

[Gooss]

Generally, I run the left wing tank dry, then switch to auto.  Then the right wing tank is my reserve.  The right wing tank and main tank will then switch back and forth as fuel is consumed.  From my recollection, it's always been that way in the -1 and -1A.

The reasoning which I now realize I've accepted at face value without testing is that the added weight in the right wing tank helps offset the tendency of the left wing to stall due to torque.  Or something. 

I kinda feel foolish now for what I am about to post.  And find it hilarious.  And will post anyway because he said "fule".

HONK!
Gooss

[hgtonyvi]

Daddyace if the fuel is highlighted in yellow and it runs out the engine will quit..you will have to switch and make sure its highlighted in white to stay auto.