SuperKermit Posted January 8 Posted January 8 Hi everybody, I just started to learn the F-4 over the holidays and I just love the module. However, I struggle to understand the fuel system completely. I read the manual and several threads here on the forum. My issue is: I run out of fuel and the engines stop, however the fuel gauge still reads 4.000 lbs+ remaining. This can't be empty fuel remaining. What do I do wrong? Forget to flip a switch? Many thanks in advance!
razo+r Posted January 8 Posted January 8 Do you have a short track? Because you don't really provide a lot of information, there would be a lot of guessing involved. Check for any switches that switched without you wanting them to switch (check double or unwanted key bindings). Check for damage. Check for random failures being dis/enabled.
SuperKermit Posted January 8 Author Posted January 8 vor 2 Minuten schrieb razo+r: Do you have a short track? Because you don't really provide a lot of information, there would be a lot of guessing involved. Check for any switches that switched without you wanting them to switch (check double or unwanted key bindings). Check for damage. Check for random failures being dis/enabled. Not right now. In the scenario where that happened, no enemies were involved. I was hoping the number 4.000 lbs would ring some bells at someone like "ah, that's wing tank capacity, maybe you forgot to activate wing tanks." BTW: what happens when I do not have an external tank loaded, but the Ext. Fuel Feed Switch is switched to e.g. Center Tank Feed - would that prevent fuel from the wing tanks being used?
razo+r Posted January 8 Posted January 8 9 minutes ago, SuperKermit said: Not right now. For future reference, always try to attach one. It helps a lot. 9 minutes ago, SuperKermit said: In the scenario where that happened, no enemies were involved. I was hoping the number 4.000 lbs would ring some bells at someone like "ah, that's wing tank capacity, maybe you forgot to activate wing tanks." 4000 is as far as I saw indeed the wing tank capacity. Did you flip the "Stop Trans (Internal Wing)" switch by any chance? 9 minutes ago, SuperKermit said: BTW: what happens when I do not have an external tank loaded, but the Ext. Fuel Feed Switch is switched to e.g. Center Tank Feed - would that prevent fuel from the wing tanks being used? Wing Tanks should still transfer in a normal manner.
SuperKermit Posted January 8 Author Posted January 8 vor 14 Minuten schrieb razo+r: 4000 is as far as I saw indeed the wing tank capacity. Did you flip the "Stop Trans (Internal Wing)" switch by any chance? Hm, could be possible. What is the default setting of that switch? Anyhow, somewhere I read that the fuel system has an emergency function that enables fuel flow from all tanks in a low fuel state regardless of the switch settings.
razo+r Posted January 8 Posted January 8 (edited) 7 minutes ago, SuperKermit said: Hm, could be possible. What is the default setting of that switch? Normal. Edited January 8 by razo+r 1
Zabuzard Posted January 8 Posted January 8 Did you fly with afterburner on for a few minutes? Possibly even some negative Gs?The system cant feed faster than the AB burns.But yeah, smells like you trapped the wing fuel. There are several ways to do so. 1
Solution Zabuzard Posted January 8 Solution Posted January 8 Not right now. In the scenario where that happened, no enemies were involved. I was hoping the number 4.000 lbs would ring some bells at someone like "ah, that's wing tank capacity, maybe you forgot to activate wing tanks." BTW: what happens when I do not have an external tank loaded, but the Ext. Fuel Feed Switch is switched to e.g. Center Tank Feed - would that prevent fuel from the wing tanks being used? The External Tank Feed switch must be in OFF for the internal wing tanks to be used.They both share the same pipes and if the valve is in the wrong setting you are only allowing the non-existent ext tanks to feed, not the internal wing tanks.The aircraft has no awareness of ext tanks being loaded or not. So if you select ext tanks to feed, but have none, you are still blocking your internal wing tanks. 2 1
razo+r Posted January 8 Posted January 8 (edited) 16 minutes ago, Zabuzard said: The External Tank Feed switch must be in OFF for the internal wing tanks to be used. They both share the same pipes and if the valve is in the wrong setting you are only allowing the non-existent ext tanks to feed, not the internal wing tanks. The aircraft has no awareness of ext tanks being loaded or not. So if you select ext tanks to feed, but have none, you are still blocking your internal wing tanks. Then I guess this snipped is not applicable for our aircraft? Edited January 8 by razo+r 1
SuperKermit Posted January 8 Author Posted January 8 vor 2 Stunden schrieb Zabuzard: Did you fly with afterburner on for a few minutes? Possibly even some negative Gs? The system cant feed faster than the AB burns. Ah, that’s new to me. Must have missed that in the manual. vor 2 Stunden schrieb Zabuzard: The aircraft has no awareness of ext tanks being loaded or not. So if you select ext tanks to feed, but have none, you are still blocking your internal wing tanks. Thx for the explanation! It seems I have misunderstood that emergency function that force feeds fuel. This is from the manual: ”When the aircraft reaches a low fuel state automatic fuel transfer activates, forcing valves from internal wing and external tanks open regardless of what has been selected on the panel.” Shouldn’t that prevent the situation I experienced? Or does that system bot kick in because it thinks I have 4.000 lbs remaining?
Zabuzard Posted January 8 Posted January 8 Thx for the explanation! It seems I have misunderstood that emergency function that force feeds fuel. This is from the manual: ”When the aircraft reaches a low fuel state automatic fuel transfer activates, forcing valves from internal wing and external tanks open regardless of what has been selected on the panel.” Shouldn’t that prevent the situation I experienced? Or does that system bot kick in because it thinks I have 4.000 lbs remaining?The automatic fuel transfer system kicks in when cell 1 + 2 drop below a threshold, so it likely did activate in your case.I need to doublecheck the code tomorrow to tell you how it behaves exactly when wing tank + ext tank are selected. But I do for example recall that this system overrides the "stop internal wing transfer" switch.Then again, there could be other reasons. Perhaps you pulled some heavy G or extreme outside temps or sth and one of the valves broke or got stuck. Perhaps just momentarily but while you were in AB.If you can reproduce it and send a track, it would be awesome. Then I just have to launch the track with the debugging interface open and can see the status of the entire fuel system within a second :) 1
SuperKermit Posted January 8 Author Posted January 8 I found the reason. First I have to apologize and thank you for giving thoughts to my issue. Ahem… I mistakenly bound the gear lever on my throttle to the gear circuit breaker instead of the gear itself. So the gear never went up after takeoff which stopped the fuel flow from the wing tanks Sorry for the confusion and thanks again for your support! P.S.: it’s amazing how good that thing flies even with the gear down 2
MAXsenna Posted January 8 Posted January 8 I found the reason. First I have to apologize and thank you for giving thoughts to my issue. Ahem… I mistakenly bound the gear lever on my throttle to the gear circuit breaker instead of the gear itself. So the gear never went up after takeoff which stopped the fuel flow from the wing tanks Sorry for the confusion and thanks again for your support! P.S.: it’s amazing how good that thing flies even with the gear down Try fly it with the shute out! Sent from my SM-A536B using Tapatalk 2
SuperKermit Posted January 9 Author Posted January 9 vor 13 Stunden schrieb MAXsenna: Try fly it with the shute out!
razo+r Posted January 13 Posted January 13 On 1/8/2025 at 5:54 PM, razo+r said: Then I guess this snipped is not applicable for our aircraft? @Zabuzard May I have some more details regarding this here?
Zabuzard Posted January 13 Posted January 13 1 hour ago, razo+r said: @Zabuzard May I have some more details regarding this here? Bug, has been fixed for the next update 1 2
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