balus

Fuel management tutorial

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Is it possible for more detail of the fuel management required to be included in the tutorial, or perhaps form part of another tutorial? I have followed the tutorial as closely as possible and still seem to be having fuel management issues - mainly tank 1 main running out before the others.

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The cheat sheet looks good.

 

Here are a few pointers. 

 

Only use the pop-up loader to put fuel in the aircraft.  It will always distribute fuel between the tanks in the correct way. 

 

Leave the tanks selector levers, aside from the centre ones, alone.  They are not used in normal operations.  Each engine draws from it's main tank.  The levers allow fuel to be drawn directly from the alternate tanks, but you would only do that if the main tank had a faulty pump or was leaking, etc.  If you start messing with the levers it will cause problems with fuel distribution and you also might turn off the fuel flow by mistake and shut down an engine in flight. 

 

Only use the pop-up loader to put fuel in the aircraft.  It will always distribute fuel between the tanks in the correct way. 

 

The main tank boost switches have nothing to do with fuel transfer (except for transfer from the Nos 1 or 4 main tanks to their respective alt tanks which you would not normally do).  They just help out the engine driven pumps in some circumstances. 

 

On most flights, you can get away with putting off fuel management until you get to cruise, even if there is fuel in the centre tanks.  If you are still at the stage where you're not sure what you're doing with fuel management, it might be a good idea not to do it until you are in cruise. 

 

The basic steps with the fuel management is first to get the fuel out of the centre tanks into the main tanks.  But on most flights (except very long ones) you aren't going to have any fuel in the centre tanks so you skip ahead to step 3 under "cruise" in the fuel management manual. Here you begin transferring fuel out of the inboard alternate tanks into the inboard main tanks.  You want to to the same with the outboard tanks (nos. 1 & 4) but first you need to wait until the fuel in nos.1 & 4 main tanks is below 7,500 lbs.  Then you turn on the alternate pumps and open the number 1 & 4 main tank valves.  However, note that fuel will not transfer until the automatic shutoff valves open, which will happen when these main tanks get to just under 7000 lbs.  We had a former flight engineer on the beta who told us that these restrictions with weight in the number 1 and 4 alternate and main tanks were so as to not allow a weight distribution that Douglas felt could lead to flutter developing in the wings. 

 

If you turn the auto shutoff valve switch to closed, the blue lights will show which tanks have their auto shutoff valves open to receive fuel. (The lights go off if the valves are open.) The switch has nothing to do with operation of the valves, it only shows their status or turns the indicator lights off.

 

4 hours ago, balus said:

I have followed the tutorial as closely as possible and still seem to be having fuel management issues - mainly tank 1 main running out before the others.

 

As for the number 1 main tank running low before the others, did you possibly open the fill valve to the No.1 alt tank by mistake?  This will put fuel from the main into the alternate tank if the main boost pump is on.

 

Did you install XMLTools as requested in the Important please read sticky post near the top of the forum? The fuel system won't work properly without it.

 

Do you have any controllers assigned to fuel mixture that might be causing problems?  One of the beta testers at one point set up his controllers for a prop aircraft and it caused total havoc when he went back to the DC8.

 

Are you loading some other aircraft first, before the DC8?  I wouldn't think that would cause problems, but would like to rule it out. 

 

If you just sit on the ground with the engines running, (maybe turn on time acceleration) does the no 1 main tank drop fuel faster than the others?

 

Maybe during a flight, when you think the fuel system is starting to go wrong you could take a screenshot of the fuel panel and post it here.

 

 

 

 

 

 

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6 hours ago, triflyman said:

Attached is a Fuel Management "cheat sheet" that I use...if it helps.

 

Fuel Management_v2.pdf

Hi triflyman,

thanks a lot for posting the document. I were so free to convert it to a pdf file, is more safe then posting doc files. ;)

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15 hours ago, triflyman said:

Attached is a Fuel Management "cheat sheet" that I use...if it helps.

 

Fuel Management_v2.pdf

Thanks, Triflyman, very helpful.

 

One minor comment: your cheat sheet mentions cross-feed, but it appears these levers are not working.

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14 hours ago, Michael2 said:

The cheat sheet looks good.

 

Here are a few pointers. 

 

Only use the pop-up loader to put fuel in the aircraft.  It will always distribute fuel between the tanks in the correct way. 

 

Leave the tanks selector levers, aside from the centre ones, alone.  They are not used in normal operations.  Each engine draws from it's main tank.  The levers allow fuel to be drawn directly from the alternate tanks, but you would only do that if the main tank had a faulty pump or was leaking, etc.  If you start messing with the levers it will cause problems with fuel distribution and you also might turn off the fuel flow by mistake and shut down an engine in flight. 

 

Only use the pop-up loader to put fuel in the aircraft.  It will always distribute fuel between the tanks in the correct way. 

 

The main tank boost switches have nothing to do with fuel transfer (except for transfer from the Nos 1 or 4 main tanks to their respective alt tanks which you would not normally do).  They just help out the engine driven pumps in some circumstances. 

 

On most flights, you can get away with putting off fuel management until you get to cruise, even if there is fuel in the centre tanks.  If you are still at the stage where you're not sure what you're doing with fuel management, it might be a good idea not to do it until you are in cruise. 

 

The basic steps with the fuel management is first to get the fuel out of the centre tanks into the main tanks.  But on most flights (except very long ones) you aren't going to have any fuel in the centre tanks so you skip ahead to step 3 under "cruise" in the fuel management manual. Here you begin transferring fuel out of the inboard alternate tanks into the inboard main tanks.  You want to to the same with the outboard tanks (nos. 1 & 4) but first you need to wait until the fuel in nos.1 & 4 main tanks is below 7,500 lbs.  Then you turn on the alternate pumps and open the number 1 & 4 main tank valves.  However, note that fuel will not transfer until the automatic shutoff valves open, which will happen when these main tanks get to just under 7000 lbs.  We had a former flight engineer on the beta who told us that these restrictions with weight in the number 1 and 4 alternate and main tanks were so as to not allow a weight distribution that Douglas felt could lead to flutter developing in the wings. 

 

If you turn the auto shutoff valve switch to closed, the blue lights will show which tanks have their auto shutoff valves open to receive fuel. (The lights go off if the valves are open.) The switch has nothing to do with operation of the valves, it only shows their status or turns the indicator lights off.

 

 

As for the number 1 main tank running low before the others, did you possibly open the fill valve to the No.1 alt tank by mistake?  This will put fuel from the main into the alternate tank if the main boost pump is on.

 

Did you install XMLTools as requested in the Important please read sticky post near the top of the forum? The fuel system won't work properly without it.

 

Do you have any controllers assigned to fuel mixture that might be causing problems?  One of the beta testers at one point set up his controllers for a prop aircraft and it caused total havoc when he went back to the DC8.

 

Are you loading some other aircraft first, before the DC8?  I wouldn't think that would cause problems, but would like to rule it out. 

 

If you just sit on the ground with the engines running, (maybe turn on time acceleration) does the no 1 main tank drop fuel faster than the others?

 

Maybe during a flight, when you think the fuel system is starting to go wrong you could take a screenshot of the fuel panel and post it here.

 

 

 

 

 

 

 

Thanks Michael,

 

I did install the XML tools, I do use a CH Yoke that has the mixture axis assigned, I wonder if this is causing an issues, not that I am using it though... Sadly it is Monday here so I will have to wait until the weekend before I can make another attempt :(

 

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