Manual fuel tank selection: Does it Really Make a Difference?

[Randy1]

Manual tank selection is like manual trim I have found out in that it takes a bit of practice to make it second nature.  I use manual trim all of the time now.  Manual tank selection on the two planes I fly most, the 38 and 47 do not seem to gain much with manual tank selection from the replies I have received.

For now it is back to auto tank selection.

One thing I did learn from manual is good understanding of the auto tank rotation.  This helps when checking the gauge for remaining fuel.  I know if it is on the LM as an example, I know the aux is empty and because the tanks change often, the gauge is right wither it is LM or RM.

Thanks for all the replies.

[WW1965]

It is plane dependent.  For the P-47, you have a small aux tank that is rarely damaged and a large main tank that is frequently damaged.  The normal order burns the aux tank first, leaving you with no reserve when your main tank gets holed. 

Hmm... thanx for this..

Wrngway

[pangea]

    In the 190-d ALWAYS select front tank first and keep the rear as reserve. Unless you take 100% then I drain the rear at least halfway.
    The front tank will get shot out first leaving you with no fuel if you ran out the rear when leaving fuel on auto. This is most noticeable when hit by ack. 

Is this optimal for the 190 from a CG/handling perspective?  I had always assumed that it would be better to burn the aft tank first.

[Slate]

Is this optimal for the 190 from a CG/handling perspective?  I had always assumed that it would be better to burn the aft tank first.

   I think you are right from a center of gravity point of veiw. You can burn the aft down to 1/4 and still have enough to make it back to a friendly base if not too far. I would still keep some in the aft tank because handling really goes away when the engine cuts out. 

[-ammo-]

It is plane dependent.  For the P-47, you have a small aux tank that is rarely damaged and a large main tank that is frequently damaged.  The normal order burns the aux tank first, leaving you with no reserve when your main tank gets holed. 

   exactly

[-ammo-]

I find that a full aux tank in the P47 makes it a little more difficult to control in stalling maneuvers. If I leave fuel in the AUX it is no more than 25% - this can still carry you quite a long way if you can fly at reduced RPM (i.e. disengage from combat before the main tank runs dry).

I haven't noticed that but I am now curious.  I will pay attention for a few sorties and see.  Thanks mate

[Zerstorer]

It seems to help the stability of the Ta152 to burn the aft tank first if you take over 50% fuel....not that the 152 can be considered stable even with it burned, but it helps. 

[mthrockmor]

I primarily fly the Fw-190A5 and -D9. With both birds, I always burn the 'forward' tank down to 50% then shift back into automatic burn. I always take the drop tank as well, which means when I shift to automatic it will burn the drop tank, then to 'auxiliary,' then to 'forward.' When I get to 'forward' I have roughly 10 minutes to disengage and land.

With the 'forward' tank full the 190 is relatively unstable when it comes to firing. You will notice the nose porpoising around at key moments. Drop the 'forward' fuel to 50% and it is much more stable.

Similar discussion with the PonyD. With the 'auxiliary' tank full ACM habits are rough. Once you have burned the 'auxiliary tank to empty the PonyD is pretty agile. The difference between the burn of the 190 and PonyD is that the 'auxillary' tank is the first one to burn in both birds. Stay in auto mode with the PonyD, shift tanks in the 190.

The Ta-152 is a different story, or so I am told.

Boo

[FLS]

I believe the auto fuel tank selection is based on maintaining the proper CG for the aircraft. As mentioned there are good reasons to keep a little fuel in reserve in an separate tank.

[Randy1]

I believe the auto fuel tank selection is based on maintaining the proper CG for the aircraft. As mentioned there are good reasons to keep a little fuel in reserve in an separate tank.

No, not in every plane.  The P-38 pulls fuel out of the aux to make room for carburetor venting.  The tanks are ran for 15 minutes then switched to drain the mains. 

Why would you call a tank an auxiliary if you drain it first?

[FLS]

Randy I think you're confusing Aces High auto fuel selection with the recommendations for real aircraft.

The P-38G has main and reserve tanks. The L and later J models add wing tanks. In AH the reserve tank is labeled A, presumably for aux tank.
The wing tanks are apparently combined with either the aux or main tanks. I haven't tested to find out which one.

[Randy1]

Randy I think you're confusing Aces High auto fuel selection with the recommendations for real aircraft.

My point was although it might have been vague, is that draining the aux first in a P38 is not for plane cg purpose in AH or in real life.

With balls to the wall, in AH with 75% fuel the aux tank will be just about empty in fifteen minutes.  Of course in real life full throttle for the first fifteen minutes would not be the case in a noncombat situation. 

What would be nice albeit a low priority would be in in AH for the 38 would be an auto tanks selection would be to start with the main tanks then aux.  Or maybe a scaled back real life model with say 5 minutes on the aux then auto switch to the mains.

[FLS]

Does the CG to center of lift improve or get worse when the aux tank is burned first?

[Randy1]

Does the CG to center of lift improve or get worse when the aux tank is burned first?

I would say no.  Draining the wing tanks would seem to make the most difference in a J in real life but in AH Ak-Ak post no advantage.  Hard to argue with Ak-Ak on a P-38 AH question. I go with his answer.

[FLS]

According to HiTech, IIRC, the auto fuel selection sequence is coded to maintain the CG.