leg5840 Posted January 20, 2024 Posted January 20, 2024 If the CFT FUEL CONT' S/W is not set to STOP REFUEL, fuel should transfer from the EXT' WING/CTR FUEL TANK to both the CFT and INTL TANK, but it is not transferring to the CFT. Am I misunderstanding something?
leg5840 Posted January 20, 2024 Author Posted January 20, 2024 23 minutes ago, Rainmaker said: 거짓... 그건 틀렸어요. Is there a reason why the transfer should not occur?
Solution Rainmaker Posted January 20, 2024 Solution Posted January 20, 2024 4 minutes ago, leg5840 said: Is there a reason why the transfer should not occur? yes...incon valves powered closed 1
leg5840 Posted January 20, 2024 Author Posted January 20, 2024 20 minutes ago, Rainmaker said: 네...인콘 밸브는 전원이 닫혀있습니다 Ah... right. When the MASTER S/W is on, the TRANSFER PUMP operates, preventing refueling. Silly question...
Rainmaker Posted January 20, 2024 Posted January 20, 2024 9 hours ago, leg5840 said: Ah... right. When the MASTER S/W is on, the TRANSFER PUMP operates, preventing refueling. Silly question... Well, not even that really. CFT pumps are designed not to run when external bags are transferring (not currently implemented). The only way to transfer into the CFTs like that is manually through a ground initiated process. Fuel is designed to transfer external to internal, not across external. 1
jaylw314 Posted January 20, 2024 Posted January 20, 2024 3 hours ago, Rainmaker said: Well, not even that really. CFT pumps are designed not to run when external bags are transferring (not currently implemented). The only way to transfer into the CFTs like that is manually through a ground initiated process. Fuel is designed to transfer external to internal, not across external. At least looking at the fuel system schematic in the dash 1, it's not entirely clear why this is the case, since it shows the refueling lines to the CFT's and the external tanks are all just hooked up to the main refueling line, and it notes the refueling valves to the CFT's should be open when the CFT pumps are off. So far, all the SME's I've heard have agreed this should not happen though, so I assume there's something missing in the diagram. Could it be that the tank pressurization in the CFT's is higher than the internal tanks? I couldn't find any reference to those pressures, but that would prevent the external tanks from feeding into the CFT's at any time, even with the CFT refueling valve open
leg5840 Posted January 20, 2024 Author Posted January 20, 2024 4 hours ago, Rainmaker said: Well, not even that really. CFT pumps are designed not to run when external bags are transferring (not currently implemented). The only way to transfer into the CFTs like that is manually through a ground initiated process. Fuel is designed to transfer external to internal, not across external. I started this topic thinking that fuel was being supplied to the CFT during the ext' fuel tank transfer check on the ground, and that it would be the same in the air. (Of course, the MASTER S/W is off on the ground.) This is because in DCS, even if the wow is on, when the gear handle is up on the ground, fuel is transferred from the ext' fuel tank to INTL.(I haven't actually tried it on a real aircraft) I'll study more about this and get back to you, sir.
Rainmaker Posted January 21, 2024 Posted January 21, 2024 2 hours ago, jaylw314 said: At least looking at the fuel system schematic in the dash 1, it's not entirely clear why this is the case, since it shows the refueling lines to the CFT's and the external tanks are all just hooked up to the main refueling line, and it notes the refueling valves to the CFT's should be open when the CFT pumps are off. So far, all the SME's I've heard have agreed this should not happen though, so I assume there's something missing in the diagram. Could it be that the tank pressurization in the CFT's is higher than the internal tanks? I couldn't find any reference to those pressures, but that would prevent the external tanks from feeding into the CFT's at any time, even with the CFT refueling valve open No. You are looking at a very simplified block diagram of the system. The real thing has a ton of components in the mix. The -1 diagrams arent meant to show it all, they are there to supplement what the -1 is saying earlier. That’s why they are supplements and not GS/SD diagrams. Manually transferring gas is something that can only be done by mx crews using the ground check panel below the aircraft. None of that stuff pertains to aircrew, so zero reason to go into it in a -1. 1
jaylw314 Posted January 21, 2024 Posted January 21, 2024 1 hour ago, Rainmaker said: No. You are looking at a very simplified block diagram of the system. The real thing has a ton of components in the mix. The -1 diagrams arent meant to show it all, they are there to supplement what the -1 is saying earlier. That’s why they are supplements and not GS/SD diagrams. Manually transferring gas is something that can only be done by mx crews using the ground check panel below the aircraft. None of that stuff pertains to aircrew, so zero reason to go into it in a -1. "It's complicated." Cool beans, thanks!
Rainmaker Posted January 21, 2024 Posted January 21, 2024 (edited) 1 hour ago, jaylw314 said: "It's complicated." Cool beans, thanks! In a way, yeah. The CFTs and tanks can both be thought up as external gas. Fuel goes external to internal. It should do either the CFTs or tanks and then the other once empty. It doesnt currently, but I wouldn’t say its an issue, just needs more development. Edited January 21, 2024 by Rainmaker 1
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