camsr Posted January 16, 2014 Posted January 16, 2014 Is this for the obvious? Fuel from both tanks to both engines? Any need to use this when refueling?
Oznerol256 Posted January 16, 2014 Posted January 16, 2014 AAR fills all tanks available except from the ones that you disabled using the "fill disable" buttons. AFAIK, fuel cross-feed does exactly what you wrote. both engines get their fuel from both fuel systems. However, there is also a gate valve (TK GATE or something). If you open it, the fuel can flow freely from one system to the other. I can't think of a situation to use it, but it is there. [sIGPIC][/sIGPIC]
lanmancz Posted January 16, 2014 Posted January 16, 2014 (edited) From manual (page 133) : Crossfeed Switch. Although the A-10C fuel system is designed with two parallel fuel systems, setting the Crossfeed switch to CROSSFEED will link the two fuel systems and allow the boost pumps to feed both engines. If the Crossfeed switch is set to OFF, both fuel systems are isolated. You would most often use Crossfeed when one of the boost pumps fails. Tank Gate Switch. Linking the left and right main fuel tanks is a transfer valve that may be opened by setting the TK GATE switch to the OPEN position. Setting this switch to CLOSE will isolate the two tanks from each other. Generally you will want to keep this switch disabled as being enabled can lead to fuel center of gravity problems. Edited January 16, 2014 by lanmancz [sIGPIC][/sIGPIC] Gigabyte Aorus Z390 Elite, Intel i9 9900K, Fractal Design Kelvin S36, Zotac GTX 1070 8GB AMP Extreme, 32GB DDR4 HyperX CL15 Predator Series @ 3000 MHz, Kingston SSD 240GB (OS), Samsung 970 EVO 1TB M.2 NVMe (sim), Fractal Design Define R5 Black Window, EVGA SuperNOVA 750 G2, Win 10 Home x64, Thrustmaster Warthog HOTAS, Saitek Pro Flight Rudder Pedals, Thrustmaster MFD Cougar Pack, TrackIR (DelanClip), 3x 27" BenQ EW2740L, Oculus Rift S
Evil.Bonsai Posted January 17, 2014 Posted January 17, 2014 I'm almost wanting to try filling tanks partway, activating the tank gate switch, then rolling to one side for a bit, disable the switch, then see if level flight is affected.
howie87 Posted January 17, 2014 Posted January 17, 2014 I'm almost wanting to try filling tanks partway, activating the tank gate switch, then rolling to one side for a bit, disable the switch, then see if level flight is affected. Already tried it. Didn't work. It does level the tanks out though if they are unbalanced. Basically if you lose an engine and forget to enable cross feed, flip the tank gate switch and it will level out the tanks.
Evil.Bonsai Posted January 17, 2014 Posted January 17, 2014 Yeah, just tried it and no change to levels. Hopefully I'll remember that when I lose an engine.
camsr Posted January 17, 2014 Author Posted January 17, 2014 So is there a reason to use the cross-feed during normal flight? Since I started using the throttles separately it's been on my mind. I have seen the fuel gauge report most all the fuel in the fuselage tanks on a light load, but if they are coaxial then I don't think it matters so much?
RICARDO Posted January 17, 2014 Posted January 17, 2014 hello, i was wondering what i should do in two different situation: 1/- my right engine has been hit and turns with very low rpm. left wing fuel level is getting low faster than right one 2/- my left wing has been shot and i have an heavy leak of fuel. i should have soon my left engine out of fuel. thanks for your advices.
Snoopy Posted January 17, 2014 Posted January 17, 2014 hello, i was wondering what i should do in two different situation: 1/- my right engine has been hit and turns with very low rpm. left wing fuel level is getting low faster than right one 2/- my left wing has been shot and i have an heavy leak of fuel. i should have soon my left engine out of fuel. thanks for your advices. Page 56. http://www.476vfightergroup.com/downloads.php?do=file&id=29 v303d Fighter Group Discord | Virtual 303d Fighter Group Website
Shadow KT Posted January 17, 2014 Posted January 17, 2014 (edited) AAR fills all tanks available except from the ones that you disabled using the "fill disable" buttons. AFAIK, fuel cross-feed does exactly what you wrote. both engines get their fuel from both fuel systems. However, there is also a gate valve (TK GATE or something). If you open it, the fuel can flow freely from one system to the other. I can't think of a situation to use it, but it is there. Here is one... I got shot and was leaking fuel trough one the of wings. After flying back to base for some time I could feel the plane didn't want to stay stable and was going to one of the sides. Looked at my fuel gauge and saw a big difference in fuel levels between the two sides. Switched cross-feed on and for couple of minutes I got it stabilized. Although have cross-feed makes you bleed more fuel Edited January 17, 2014 by Shadow KT 'Shadow' Everybody gotta be offended and take it personally now-a-days
Oznerol256 Posted January 17, 2014 Posted January 17, 2014 Here is one... I got shot and was leaking fuel trough one the of wings. After flying back to base for some time I could feel the plane didn't want to stay stable and was going to one of the sides. Looked at my fuel gauge and saw a big difference in fuel levels between the two sides. Switched cross-feed on and for couple of minutes I got it stabilized. Although have cross-feed makes you bleed more fuel Actually, i wouldn't have expected that. I thought the engines would use fuel from both fuel systems at the same rate (50/50) once XFEED is open. However, your example shows that it doesn't. It obviously tries to balance the fuel systems out. That offsets the use of TK GATE oven more. [sIGPIC][/sIGPIC]
Shadow KT Posted January 17, 2014 Posted January 17, 2014 Actually, i wouldn't have expected that. I thought the engines would use fuel from both fuel systems at the same rate (50/50) once XFEED is open. However, your example shows that it doesn't. It obviously tries to balance the fuel systems out. That offsets the use of TK GATE oven more. Actually I can't quite remember if I had TK GATE open, cuz it was like half an year ago or smthing :D or even more. But I'll do a test when I get up from bed later today :) 'Shadow' Everybody gotta be offended and take it personally now-a-days
howie87 Posted January 18, 2014 Posted January 18, 2014 (edited) Pretty sure if you get a fuel imbalance warning light on the caution panel flipping the tank gate switch gets rid of it and balances the tanks... From the manual: "Tank Gate Switch. Linking the left and right main fuel tanks is a transfer valve that may be opened by setting the TK GATE switch to the OPEN position. Setting this switch to CLOSE will isolate the two tanks from each other. Generally you will want to keep this switch disabled as being enabled can lead to fuel center of gravity problems" The 476th cockpit familiarisation guide (http://www.476vfightergroup.com/downloads.php?do=file&id=85) states: "OPEN supplies power to open the gate valve linking the left and right main fuel tanks. Fuel in the main tanks will be below the tank gate valve and will not transfer in level flight when the fuel level is below 1,300 pounds in each main tank. The sump fuel will not flow between the tanks. CLOSE closes the gate valve." Generally I only use it as a last resort though, when I've already got a large fuel imbalance and want to QUICKLY even the tanks out. I usually just flip it open, give it a few seconds, check the fuel levels then flip it back to close. Crossfeed can take a while to achieve the same thing. Edited January 18, 2014 by howie87
PFunk1606688187 Posted January 18, 2014 Posted January 18, 2014 I assume its called left and right to identify which fuel system each tank serves rather than its relative internal positioning. Warning: Nothing I say is automatically correct, even if I think it is.
Shadow KT Posted January 18, 2014 Posted January 18, 2014 (edited) ..... These 'left' and 'right' fuel tanks are positioned in the fuselage, forward and aft. So yeah, you can 'balance' between fuel tanks, but it's not between left and right, it's between forward and aft. And this is VERY VERY dangerous to do as it will mess up your longitudinal CG. Just use XFEED and forget about the TK GATE. Hey DUTCH GUY...YOUR PICTURE IS LYING AND YOU TOO ARE LYING...THE A-10 HAS ONLY 1150 ROUNDS .TAKE THAT . Lets FIGHT. P.S: Joking about you lying...tho the A-10 has only 1150 rounds :D ch33rs Edited January 18, 2014 by Shadow KT 'Shadow' Everybody gotta be offended and take it personally now-a-days
Yurgon Posted January 19, 2014 Posted January 19, 2014 So yeah, you can 'balance' between fuel tanks, but it's not between left and right, it's between forward and aft. In case you don't currently have a Dash One at hand, let me quote. Aircraft Fuel System The aircraft fuel supply system (...) consists of two internal wing tanks (left and right wing), and two tandem-mounted fuselage tanks (left main-aft and right main-forward). [...] The fuel supply system operates as two independent subsystems, with the left wing and left main tank feeding the left engine and the APU, and the right wing and right main tank feeding the right engine. The two subsystems can be interconnected by opening crossfeed valves (controlled by a single switch in the cockpit) to allow pressurized fuel flow to both engines and the APU from either subsystem. In addition, the two main tanks can be interconnected by opening a tank gate valve. The "General Arrangement Diagram" on page 1-2 provides further explanation and clarification. This is from the 1A-10A-1, but I believe it's entirely valid for the A-10C as well.
Deadman Posted January 19, 2014 Posted January 19, 2014 (edited) SHaDoW STeP BG you may wish to do some researcher on the difference between the magazine capacity of the GAU 8 (1350) and the number of rounds in the cans of ammo 575 each X 2 equals 1150 http://www.atk.com/wp-content/uploads/2012/09/AS-GAU-8A.pdf http://www.airforce-technology.com/projects/a-10/ Edited January 19, 2014 by Deadman https://forum.dcs.world/topic/133818-deadmans-cockpit-base-plans/#comment-133824 CNCs and Laser engravers are great but they can't do squat with out a precise set of plans.
camsr Posted January 19, 2014 Author Posted January 19, 2014 I tried the TK GATE thing, set it to open and sloshed fuel to both tanks. It's tricky getting fuel into the front tank, but if you dive roughly 20º and don't exceed 1g it works. Then a warning light comes on that the tanks are unbalanced. I think it only works if you have over a certain amount of fuel, not sure. Maybe upside down would exchange them faster...
Shadow KT Posted January 19, 2014 Posted January 19, 2014 Could be ... everything was intended just to poke GRZLY for the jokes and laughs. I believe you ^^ 'Shadow' Everybody gotta be offended and take it personally now-a-days
Evil.Bonsai Posted January 19, 2014 Posted January 19, 2014 Note: The tankgate is simply a hole between FORWARD and AFT fuselage fuel tanks that can be opened and closed. So banking left and right is useless. I don't think it's used to level tanks. I can't think of a situation where you would need the tankgate... Well now that I know that... tried again and it did move between tanks a bit. I was pretty low so didn't have much time to test. Next time I'll start at 40K, drop throttle and flaps, open brakes all the way and point nose down.
kk0425 Posted January 20, 2014 Posted January 20, 2014 The only scenario I can really think of is if you got shot and lost one of your main boost pumps and forgot to turn on the xfeed switch, so you have a major imbalance, or one of your main fuel tanks is leaking. In either case you do not want to be flying with a large imbalance as was mentioned earlier, it will cause major center of gravity problems and make it much less stable in flight. Something you don't want, especially when trying to land.
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