Fuel system¶
The mod uses Asobo's modern, modular fuel system which simulates fuel lines, pumps, and valves to connect tanks to engines.
The main tanks are under the cabin floor. When the fuel selector switch is in the BOTH position, the FWD tank feeds the right engine, the AFT tank the left engine. Setting the fuel selector to FWD or AFT opens the crossfeed valves, forces both boost pumps (main pump and emergency pump) on for this tank and disables the boost pumps in the other tank.
Based on pilot feedback, I removed the boost pump requirement when operating below 8,000 ft density altitude.
Wing tanks¶
The wing tanks cannot feed engines directly. With the fuel pump switch in the (mislabeled) "Engine" position, fuel is transferred from the respective wing tank to its main tank: the right wing tank feeds into the FWD main tank. A float valve pauses the transfer before the target main tank reaches capacity. If the wing tank is empty and the pump can no longer draw fuel, the respective wing tank pump failure warning light will illuminate on the annunciator panel. The "Refuel" position does nothing.
Note
The modular fuel system has some limitations that I work around with config tricks and custom code. Examples:
Fuel is fed from the wing tanks into the main tanks using electric pumps. For some reason, this doesn't work as expected in the sim, so I simulate the electrical pumps using valves, gravity feeds and electrical phantom consumers.
The sim controls the engine-driven pumps based on shaft RPM (prop RPM) instead of gas generator RPM and doesn't like it when boost pumps and engine-driven provide pressure simultaneously, so custom code has to orchestrate the pumps.
Reviewed 2026-08-12.