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Post by FSMuseum on Oct 17, 2014 18:42:24 GMT -5
Hi everyone,
During my brief hiatus from 3D modelling and AFCADing, I wanted to do some flying. I've been wanting to fly the connie for some time, but I can't seem to figure out all the charts and manuals used for fuel planning, despite reading them numerous times. Can someone help make this clear to me? I release it'll be different across the different connie variations, and I'm mainly looking for the 1049G and Starliner
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Post by Defender on Oct 18, 2014 7:05:02 GMT -5
Hi Chris, More than happy to help. Suggest you start with the L1049G and it's indeed a complex arrangement but it would help first to know which aspect/s cause you the greatest trouble. Is it, a. fuel loading distribution b. fuel tank use sequence c. how the tank selector levers and pump switches should be operated Of course I realise it might be all of these! I'm going to email you a tank loading chart for the 9 tank 1049G. I'm assuming you already have the 1049G's manual doc, the later update manual pdf and the 9 tank fuel management.jpg Best regards Bill
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Post by FSMuseum on Oct 18, 2014 9:43:49 GMT -5
Hi Bill,
Thank you for reaching out!
The areas that cause me the most trouble would be B and C, Fuel Tank Use Sequence and How the Tank Selector Levers and Pump Switches should be Operated.
I do have the 1049G's manuals, though I don't know if I have the later updated manual or not. Does that come with every download of the Connie? When was it updated, if so?
Thanks again, Chris
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Post by Defender on Oct 18, 2014 11:12:57 GMT -5
Hi,
Yes it's worth checking that you have all the latest. The original download was in April 2009, L1049G.zip then a bug fix update May 2009, L1049G_u.zip and finally the update in October 2010, super_constellation_fde_upgrade.zip. There might also have been a separate download with some real manual performance pages, fuel tank arrangement etc and I'll email these to you just in case they're not in the aforementioned downloads.
I'll get back later with the explanations you asked for.
Best regards
Bill
PS - I'm just back from visiting family in Vancouver and managed to get to the Seattle Museum of Flight again (third time!) to see their latest addition Super Connie CF-TGE. Also managed Kenmore Air's Beaver scenic flight to get some round engine time in.
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Post by Defender on Oct 18, 2014 13:24:13 GMT -5
Hi Chris, Whilst Volker's and Stefan's notes in the release manuals do deal with fuel management in considerable detail, here's some further explanation which hopefully assists. Fuel Tank Use Sequence
The principle behind wing loading integrity is to ensure that fuel is first used from the centre or inboard tanks so that when the aircraft is lighter and for landing all the remaining fuel is outboard, with the exception that the wing tip tanks (when fitted) must also be empty or almost so for landing. You will see from the "9 tank fuel management" document that the tank numbering is in a rather strange order but it makes more sense when you realise that for both the cruise and landing, most of the flight therefore, the primary tanks are 1/2A/3A/4 and not 1/2/3/4. So the objective is that at the end of the cruise the contents of each tank 1/2A/3A/4 (IE. the outer wing tanks) should be equal and the rest empty. The table at the top of the 9 tank fuel management doc shows how this is done starting with various initial fuel loads, the left side being the number of tank selection stages needed, just one en route change if light fuel load, up to six en route switches when take off is with full tanks. The right side shows which tank feeds each engine at each stage. Remember also that the fuel loading chart requires a minimum of 150 USG in each of 2 and 3 for T/O. So examples, starting with the lowest T/O fuel level, anything up to 2,860 USG. T/O is with tanks 1/2/3/4 and at the start of the cruise (or when 2 and 3 are nearly empty if sooner!!) you switch to 1/2A/3A/4 and leave it at that. Say you took off with 2,860 USG, spread 150 in each of 2 and 3, 565 (full) in each of 2A and 3A and therefore 715 in each of 1 and 4 (tank 1 must equal 2+2A etc total load permitting). Tip tanks 2B/3B and centre tank 5 will be empty. T/O and climb might consume 125 USG from each tank so at the start of the cruise you will have the original 565 in each of 2A and 3A, 25 in each of 2/3 (which will not be used) and 590 in each of 1 and 4, so tank 1/4 still equals 2+2A/3+3A thus no further transfers needed. Now a more difficult example with say 7,020 USG, full tanks except for tank 5. Because you need to use the full capacity of 2/3, 2A/3A and 2B/3B there's a considerable amount of switching needed to get 2/3 and 2B/3B empty and 2A/3A equal to 1/4 before you land. You take off with 1/2/3/4 (sequence #1) as usual and because tank 5 is empty you can go straight to sequence #3 at the end of the climb. Sequences #3 and #4 are very similar, you use crossfeed to get 3 engines to run off tanks 2 and 3. You use 2 and 3 first because these are the furthest inboard tanks. Then when tanks 1 and 4 equal 2+2A+2B and 3+3A+3B respectively (or more simply, tank 2 equals tank 1 minus 2A and 2B etc etc) you go to sequence #5 to drain the remainder of tanks 2 and 3. Thereafter sequence #6 to empty tip tanks 2B/3B before landing (they actually feed through 2A/3A automatically) and finally sequence #7 to set up the required 1/2A/3A/4 tank selection for landing, ensuring that tank quantities are equal. I'll send something later on tank levers, pumps etc but hope this helps meantime. If it's complex don't blame the Connie Team, blame Lockheed! Yes, Manfred, Volker and the Connie Team wanted it to be as realistic as possible, in fact just like your approach to airport design! Bill
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Post by Defender on Oct 18, 2014 16:06:06 GMT -5
How the tank selector levers and pump switches should be operated - L1049G/H
The main tank selector levers and the contents gauges for tanks 1/2/3/4 are on the FE panel, Shift+4. The crossfeed valves, aux pump switches and tank 5 selector are on the Auxiliary Control Stand, Shift+6, The contents gauges for tanks 2A/2B, 3A/3B and 5 are on the Upper FE Panel, Shift+7
In real life the aux pumps would normally be activated and possibly essential for cross feed. In this model all functions should still work with the pumps off except for tank 5 which will not supply fuel unless its pump is on.
When the FE Panel tank selectors are set to 2A/3A, any fuel in tip tanks 2B/3B will automatically be used before 2A/3A fuel and the Status panel will show that 2B/3B are in use and their contents.
If the switching is done in the right order there should be no interruption to the engine fuel supply but it takes a second or so for the Status panel to update.
So looking at the sequences in the 9 tank fuel management illustration;
Sequence #2, empty fuselage tank 5 (if used). 1. On the Aux Control Panel, tank 5 selector lever to ON (open) position, tank 5 aux fuel pump switch to HIGH and cross feed levers 1 and 4 to ON (open) 2. On the FE Panel, fuel tank levers 1 and 4 to OFF (closed).
Sequence #3, cross feed engine 1 from tank 2 1. On the Aux Control Panel, cross feed levers 1 and 2 to ON (open), tank 2 aux fuel pump switch to HIGH (if preferred), 2. On the FE Panel, fuel tank lever 1 to OFF (closed).
Sequence #4, cross feed engine 4 from tank 3 1. On the Aux Control Panel, cross feed levers 3 and 4 to ON (open), tank 3 aux fuel pump switch to HIGH (if preferred), 2. On the FE Panel, fuel tank lever 4 to OFF (closed).
NB - between or after each cross feed operation firstly restore normal fuel supply, selecting tanks 1/2A/3A/4 as per sequences #6 or 7 below then close the cross feed levers and the tank 5 lever.
Sequence #5, empty tanks 2/3 On the FE Panel, fuel tank levers 1/2/3/4 to OPEN (top position)
Sequence #6, empty tanks 2B/3B On the FE Panel, fuel tank levers 1/4 to OPEN (top position), levers 2 and 3 to tanks 2A/3A (mid position)
Sequence #7, remainder of flight and landing Same as sequence #6
Chris, I'm sure this is far more than you actually need and some of it blindingly obvious but hopefully helpful to you and possibly others anyway.
Best regards
Bill
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Post by volkerboehme on Oct 18, 2014 16:13:39 GMT -5
Hi,
I agree with Bill that the Connie fuel system is complex and confusing.
It is easier to understand when you realize that the aircraft started with just 4 tanks - 1 for each engine. Then fuel tanks had been added for the 749, a center wing tank for the 1049 and wing tip tanks for the 1049G and the Warning Stars.
Whenever the situation is critical, you'll go to the ancient tanks 1-4 and run the engines from their very own tanks, omitting long lines of plumbing and sources of possible mismanagement such as the cross-feed system, all of which was added as an afterthought. Tanks 2A/3A still have something of a special status since they can be operated from the fuel tank selector quadrant and are used as landing tanks in some versions.
So you take off with tanks 1-4, just to avoid trouble, and then switch to emptying the 'new' tanks - center wing tank to get load off the wing spar, and tip tanks. At the same time, you start to even out fuel between inboard and outboard engines. The idea is that at landing, you'll have an identical ammount of fuel available for each engine.
I have no idea why Lokheed started with different tank sizes for tanks 1/4 and 2/3 and it never got any better from then on.
Best regards, Volker
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Post by volkerboehme on Oct 18, 2014 16:20:22 GMT -5
How the tank selector levers and pump switches should be operated - L1049G/H
... In real life the aux pumps would normally be activated and possibly essential for cross feed. In this model all functions should still work with the pumps off except for tank 5 which will not supply fuel unless its pump is on... Hi Bill, thanks for giving these details - I can't really go into this myself right now. However, I think that tanks 2A/3A may be used with engine-driven pumps alone, if neccesary, and tanks 2B/3B will feed into the outboard wing tanks by gravity. So while a fuel pump might be helpful to maintain fuel pressure, it is not essential, unlike tank 5, which is at the lowest point of the fuel system and accessible only from the crossfeed system. No guarantees for that, though. Best regards, Volker
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