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Post by MarvK on Feb 13, 2011 16:00:54 GMT
First, thank you to all that make this site possible. ;D I know all the work and time that goes into it. I've looked through the handling notes for the L-1011-1, but I can't find what I'm looking for in regards to proper fuel management. Maybe it's a simple thing I've overlooked, but It's a bit confusing how the pumps/crossovers are supposed to be setup to provide an uninterrupted flow to engine #2 when the center tank empties. It's a bit scary when #2 shuts down mid-flight when I know I have enough fuel to the destination. There are 4 fuel gauges on the fuel panel, but only 3 tanks in the cfg file? Thanks Again, Marv
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Post by jimhalinda on Feb 13, 2011 18:22:47 GMT
Yeah I find that confusing as well. I just ignore the fuel gauges and try to have the same amount of fuel in all 3 tanks if possible. I've only done shorter flights (less than an hour) so I don't know whether or not I'd still run out of fuel on number 2.
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Post by kenwig0556 on Feb 13, 2011 18:55:21 GMT
I believe Ken Mitchell "repli-modeled" with 4 fuel gauges on the FE panel, but set up the config for an FS friendly 3-tank setup. Its been some time since I studied Ken's original panels, but I seem to recall that there are two "center" tanks. In other words, there IS a "method to the madness" here. George can straighten this out, I'm sure.
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Post by christrott on Feb 13, 2011 19:23:29 GMT
If you're out of fuel in the center tank, you've done something wrong. Load all 3 tanks equally then burn all 3 tanks equally. The panel is already setup to do this by default. Only time you shouldn't be feeding "tank-to-engine" is when you've got more fuel in the Center than the wings and in that case, you burn all 3 engines off the center (open crossfeeds and turn off boost pumps in wing tanks) until it's even with the wings and then change to "tank-to-engine".
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Post by aerofoto - HJG Admin on Feb 13, 2011 19:44:19 GMT
We've got no data at all regarding L1011 FUEL MANAGEMENT. I subscribe both of the .... above ! FYI .... The figures I quote (fuel quantities) in each of my "Basic Flying Guides" is really just "a convenient solution" by which to set up each aircraft at/near its MGTOW .... by means of fuel rather than payload reduction. The capacity of these aircraft (in terms of PAX/freight) remains the same, but, their weight varies considerably on the basis of fuel loadings. ALSO .... my figures are not based on realworld operations though.
They're just "convenient" for FS operations only.Each of our L1011's has the same tanking configuration .... for the sake of the panels. Following my "basic guide" in regard to fuel adjustments gets the weights right .... and which shouldn't affect range too much .... provided the right aircraft is being used for the route you want to fly Mark C AKL/NZ
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Post by George Carty - HJG on Feb 13, 2011 21:18:06 GMT
I think you need to contact Ken Mitchell -- my modifications didn't touch the fuel system.
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Post by MarvK on Feb 13, 2011 22:20:33 GMT
We've got no data at all regarding FUEL MANAGEMENT. FYI .... The figures I quote (fuel quantities) in each of my "Basic Flying Guides" is really just "a convenient solution" by which to set up each aircraft at/near its MGTOW .... by means of fuel rather than payload reduction. My figures are not based on realworld operations though.
They're just "convenient" for FS operations only.Each of our L1011's has the same tanking configuration .... for the sake of the panels, but, following my "basic guide" results in varying fuel quantities .... which shouldn't affect range too much provided you're then using the right aircraft on the route your wanting to fly of couirse Mark C AKL/NZ So Mark, if I understand what you're saying, is that the fuel quantities in the cfg files are not RW. What research I've found is that the -1 and the -50 had the same capacities at 23,600 gallons respectively. I got the info from here; home2.swipnet.se/~w-26408/1011spec.htmIn the cfg's for the -1 it's setup for 20,960 gal, and the -50 it's setup for 25,466 gal. I just did a 5hr flight from KOAK to PHNL and it worked fine. But then I started with 0 gal in the center tank. Once the #2 was running, it stayed running. Reason I'm asking all this is I, and a friend run a FS site using various aircraft to fly pax and cargo all over. I don't know if I can advertise here so I won't unless it's permissible. We have a client that adjusts fuel loads based on what's needed to complete the flight. We try to set up the aircraft as close as we can to RW specs and within FS limits.
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Post by christrott on Feb 14, 2011 1:38:57 GMT
Marv you are misreading the statements by Mark and the others.
1) The fuel quantities are correct.
2) The fuel management figures in the "handbook" are not based on any real world data.
PLEASE READ BELOW CAREFULLY:
FUELING 1) Load fuel equally into the 3 tanks until the wing tanks are full. 2) Load any remaining fuel in the Center tank until it is full.
FLIGHT MANAGEMENT 1) If the amount of fuel in the Center tank is equal to the amount of fuel in the wings, then simply burn fuel from all 3 tanks as normal at all times. 2) If the amount of fuel in the Center tank is greater than the amount of fuel in the wings, then once established in climb, open the crossfeeds and turn off the fuel pumps in the wing tanks. Once fuel in the center tank is equal to the wings, revert to #1.
Basically, if you've ever flown the 727, this is the exact same procedure. You should never have the center tank empty unless all 3 tanks are empty. As Mark said - his fuel states are simply for his convenience in testing. There have been several discussions in the past about this causing confusion, but it is his decision to operate the way he is and I'm not going to argue about it.
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Post by MarvK on Feb 14, 2011 3:10:14 GMT
Thanks for the explanation. I went back and re-read what Mark was saying. I think I understand the reasoning behind it now.
Please believe me, that I am not disagreeing with how the planes are setup, or trying to start any arguments. I just wanted to understand how they worked so we can incorporate them into our VA system.
Thanks Again, Marv
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Post by kenwig0556 on Feb 14, 2011 7:07:15 GMT
Thanks for the explanation. I went back and re-read what Mark was saying. I think I understand the reasoning behind it now. Please believe me, that I am not disagreeing with how the planes are setup, or trying to start any arguments. I just wanted to understand how they worked so we can incorporate them into our VA system. Thanks Again, Marv No problem, Marv. All questions are important. I went back and opened up the XMLs on Ken's gauges. My recollection was correct. Here's the deal: From left to right on the FE panel the gauges are titled, "2A/1/3/2B". Opening up their XMLs, I verified that 2A and 2B are redundant (duplicate) gauges pulling readings from the center tank, being "Center1" on the aircraft config. 1 is reading "LeftAux" and 3 is reading "RightAux". The bottom line is you really just have 3 tanks, but the look of a four tank setup. HJGs L1011's default fuel loads vary, naturally, by model - as reflected in their configs. You might be interested in Ken's original fuel config: "[fuel] Center1= -60.000, 0.000, -4.000, 8000.000, 3.000 LeftAux= -7.000, -35.000, 0.000, 8000.000, 3.000 RightAux= -7.000, 35.000, 0.000, 8000.000, 3.000 fuel_type=2 //Fuel type: 1 = Avgas, 2 = JetA number_of_tank_selectors=3 electric_pump=1" Happy Landings
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Post by MarvK on Feb 14, 2011 16:30:17 GMT
Thanks Ken for taking the time to look into this and explaining it. Makes perfect sense now. Cheers, Marv
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Post by christrott on Feb 14, 2011 23:48:58 GMT
One additional note as well. On the real airplane, the "#2" (Center) tank is actually located in the Wing structure inboard of the #1 and #3 engines and connected through the fuselage with piping. The DC-10 is done the same way in fact. Lockheed, however, chose to show the quantities of the 2 portions of the tank separately. Why? So that you could identify if there was an imbalance between the halves of the tank in case of a plug in the interconnect lines. Lockheed treated the "#2 Tanks" as that - separate but interconnected fuel tanks. It's an odd way to do it compared to industry standards, but it did have its advantages on the safety front.
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Post by johnyrebbaron on Sept 6, 2011 23:46:25 GMT
Hi Chris, I was reading this thread on fuel management. One because I've always had a fascination with FE panels. As a matter of fact i am working on one for the SGA DC-10. On your last reply yo mentioned how the L-1011 was similar to the DC-10 in its Fuel System. I was wondering where you found this info it would be extremely useful to me in my project.
Thank You,
Gary
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Post by christrott on Sept 7, 2011 17:20:05 GMT
I have a book (I'll have to get the specifics here in a few hours when I get home) on the L1011 that has good pics of the panels and a cutaway of some of the major systems that shows the fuel system layout. However, one thing to note is that all 3-engine jetliners have the same tank layout, 1 "main" tank for each engine and then anything else is an "aux" tank. Where the aux tanks are actually located may change from plane to plane, but the theory is the same for all jetliners. You have 1 main tank for each engine, usually located in a similar location to the engine (i.e. wing-mounted engines feed from tanks outboard of them which allows for gravity feed in an emergency, tail mounted engines feed from a centrally located tank that may or may not be able to gravity feed but usually will suction feed from an engine-mounted fuel pump in an emergency), and then aux tanks are typically located in the fuselage either in the center wing box or in the cargo hold space (reducing the cargo volume available). A few have "tip aux" or "reserve" tanks like the 747 and A3xx series of aircraft, but those are typically only used to feed directly to the adjacent tank via gravity and can't be "crossfed" to other engines directly.
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Post by johnyrebbaron on Sept 7, 2011 17:51:17 GMT
Thank You for the reply,
Any info you have would be very helpful. I don't know if you have the SGA DC-10 but it has a fuel panel that pulls up via an icon in the main panel and it is in kgrams, now i think i know ;D that a kg is 2.2 lbs but with all due respect to my cousins across the pond I deal in lbs and gallons, and i dont want to have to convert while i am flying.
I have the gauges(quantity, fuel used, and fuel used reset, fuel pressure already done what I am not sure is the crossfeeding. i think according to pics on airliners.net the dc-10-30, -40 has l,r,c,and an aux tank. Not sure how the aux tank is supposed to function.
Any help would be appreciated.
I hope I am not messing up this thread if so please let me know I will start a new one.
Thanks,
Gary
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