Fuel Tank selector to BOTH

Hi, In our aircraft, we have 4 tanks (RIght and Left Main tanks and Left-Right
Aux tanks) The fuel logic is to take fuel ONLY from Right-Left Main tanks.
When switching fuel tank selector to Right or Left it’s working great. BUT
when selecting to BOTH, It selects both AUX tanks. Do you have any idea please
? XML looks OK, flight model too. We don’t used FUEL_SYSTEM. We are using only
Fuel legacy system. Thank you so much.

This question is more for https://forums.flightsimulator.com/ This is for
SDK dev support if you find something does not work correctly or have an idea
for updates. But since you asked here is info. For your issue the reason you
are getting this result is because the fuel burns in this order when using the
simple fuel system: 1. External tanks 2. If tip tanks and aux tanks and
Center tanks are all included (center burns with tip first then aux second)
but center will go in order 3,2,1 3. tip tanks 4. aux tanks 5. main tanks.
So once the tip tanks are empty then aux tanks start to burn and once they are
empty then the main tanks. So actually left all/both or right is all based on
the logic I just shared. You need to use the complex fuel system…

[FUEL_SYSTEM]

The [FUEL_SYSTEM] section is primarily for use in complex aircraft models
where the simple
[[FUEL]](https://docs.flightsimulator.com/html/Content_Configuration/SimObjects/Aircraft_SimO/flight_model_cfg.htm#h4)
system doesn’t give enough control or flexibility for the aircraft systems.
The parameters within the
[[FUEL]](https://docs.flightsimulator.com/html/Content_Configuration/SimObjects/Aircraft_SimO/flight_model_cfg.htm#h4)
section should be used for simple aircraft or those that require a basic fuel
system setup, or for maintaining old aircraft (like ones imported from FSX).
You can find full details on the fuel system parameters from the following
page:

Hi, Thank you so much. I’ll implement FUEL SYSTEM in our aircraft. I’ll keep
you updated soon. Have a nice week.