C208 Caravan – Fuel system behaviour with both wing fuel selectors OFF
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C208 Caravan – Fuel system behaviour with both wing fuel selectors OFF
I believe there is a significant discrepancy in the Black Square C208 fuel system simulation.
On the real Cessna 208/208B Caravan, the two wing fuel tanks feed a fuel reservoir/header tank located in the cabin floor. The engine is supplied from this reservoir, which therefore provides a fuel reserve when the wing tank selectors are closed.
This is also a system behaviour that can be checked during certain maintenance inspections.
If both wing fuel selectors are inadvertently selected OFF simultaneously, the PT6 does not stop immediately. The engine continues to run on the fuel remaining in the reservoir for a limited period of time.
In the real aircraft, the POH gives approximately:
- 3 minutes at maximum continuous power
- 9 minutes at idle
In the Black Square C208, however, selecting both fuel selectors OFF results in an almost immediate engine shutdown.
This suggests that the simulation is treating the two fuel selectors as directly cutting fuel flow to the engine, rather than isolating the wing tanks while allowing the engine to consume the fuel remaining in the header/reservoir tank.
I have real-world experience with Cessna 208 maintenance, and this is a behaviour I have personally encountered during maintenance testing.
Could you please confirm whether the fuel reservoir/header tank is modelled in the current Black Square C208 fuel system, and whether the immediate shutdown with both selectors OFF is intentional or a bug?
Thank you
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Hello Black Square team,
I believe I have identified a possible discrepancy in the fuel-system simulation of the C208 Caravan.
On the real C208, the two wing tanks feed a separate reservoir/collector tank located under the cabin floor. If both wing fuel selectors are inadvertently turned OFF, the engine does not stop immediately. It continues to run from the fuel remaining in the reservoir.
A maintenance/operational test is to switch both wing fuel selectors OFF and wait for the “RESERVOIR FUEL LOW” annunciator to illuminate. The engine continues to operate for a certain period because the reservoir still contains fuel.
I have reproduced this behaviour very convincingly with the Thranda C208 in X-Plane 12:
both wing selectors OFF → engine continues running → RESERVOIR FUEL LOW illuminates → engine continues to operate from the remaining reservoir fuel.With the Black Square C208 in MSFS, however, switching both wing fuel selectors OFF appears to result in an immediate loss of engine fuel supply, without the reservoir providing the expected period of continued operation.
Could you please verify whether the reservoir/collector tank is correctly modelled in the Black Square C208, including its remaining fuel quantity and the RESERVOIR FUEL LOW warning logic?
I am familiar with the real C208 fuel system and this behaviour is a specific system test, rather than simply a difference in fuel-selector logic.
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Hello Black Square team,
I believe I have identified a possible discrepancy in the fuel-system simulation of the C208 Caravan.
On the real C208, the two wing tanks feed a separate reservoir/collector tank located under the cabin floor. If both wing fuel selectors are inadvertently turned OFF, the engine does not stop immediately. It continues to run from the fuel remaining in the reservoir.
A maintenance/operational test is to switch both wing fuel selectors OFF and wait for the “RESERVOIR FUEL LOW” annunciator to illuminate. The engine continues to operate for a certain period because the reservoir still contains fuel.
I have reproduced this behaviour very convincingly with the Thranda C208 in X-Plane 12:
both wing selectors OFF → engine continues running → RESERVOIR FUEL LOW illuminates → engine continues to operate from the remaining reservoir fuel.With the Black Square C208 in MSFS, however, switching both wing fuel selectors OFF appears to result in an immediate loss of engine fuel supply, without the reservoir providing the expected period of continued operation.
Could you please verify whether the reservoir/collector tank is correctly modelled in the Black Square C208, including its remaining fuel quantity and the RESERVOIR FUEL LOW warning logic?
I am familiar with the real C208 fuel system and this behaviour is a specific system test, rather than simply a difference in fuel-selector logic.
@Sloanof Someone asked about this a while back, here's Black Square's response: https://community.justflight.com/post/52163