Fuel Auto Balance

[dresoccer4]

so after takeoff the left fuel tank has much less fuel than the right, so i switch the auto balance switch to the left. everything goes well and the right fuel tank is drained down to match the left fuel tank. but here's where i run into an issue, according to the manual:

 

Autobalance operation ceases when:

 Difference between left and right fuel quantity indicator pointers is

within 50 to 125 pounds

and When autobalance operation ceases, the holding solenoid is deenergized,

allowing the AUTO BALANCE switch to return to the center position,

 

however in my last flight the right fuel tank continued to be drained faster and by the time i noticed anything it was almost completely depleted. anyone else notice this behavior?

[nomdeplume]

Yeah, there seems to be conflicting information in the manual and I'm not entirely sure how the system works.

 

On page 202 of the PDF, you have this:

Auto Balance Switch — LEFT LOW after fuel in external tanks is depleted.

Autobalance is started when the remaining fuel is between 4040 – 3500 pounds and is carried out until the fuel is completely depleted.

The fuel quantity indicator should be monitored to maintain the two systems within 200 pounds of each other to ensure that CG remains within limits.

 

The is carried out until the fuel is completely depleted is what I seem to experience most of the time with LEFT LOW auto-balance. The automatic shut-off seems to work reliably with RIGHT LOW. After that, setting it to LEFT LOW also causes it to automatically stop.

 

So my impression is that LEFT LOW will not stop on its own, but RIGHT LOW will, and neither will start if the tanks are already within the balance range.

[escaner]

It has always automatically deactivated for me so far. But watch out that if your left tank is lower and you select RIGHT LOW, it will completely deplete your left tank because levels will never match.

[dresoccer4]

Yeah, there seems to be conflicting information in the manual and I'm not entirely sure how the system works.

 

On page 202 of the PDF, you have this:

 

 

The is carried out until the fuel is completely depleted is what I seem to experience most of the time with LEFT LOW auto-balance. The automatic shut-off seems to work reliably with RIGHT LOW. After that, setting it to LEFT LOW also causes it to automatically stop.

 

So my impression is that LEFT LOW will not stop on its own, but RIGHT LOW will, and neither will start if the tanks are already within the balance range.

 

interesting behavior, i'll try it out