Archived

This topic is now archived and is closed to further replies.

JohnKhan

Long Range Fuel Readouts

Recommended Posts

Hi

 

I have tried to do the KATL- RJAA.  DL295 flight a couple of times and I'm getting a strange fuel system readout.

 

I load 120,000 Kg. fuel and set everything else up, I think, correctly.

 

Before push and start, the FMC/PROG page shows about 26.5 EFOB at RJAA.

 

After push and start, and during the taxi out,  I get an "Insufficient fuel" message on the FMC, and a "Fuel Disagree".  When I check the fuel quantity in the FMC/ PERF page, it has gone down to about 77.000 Kg. for some reason. 

 

The fuel quantity on the Menu/FS Action/FUEL page  is still showing 119.5 Kg. or so, but the FMC/PERF page shows that 77.0.

 

It is easily correctable by re-entering the fuel amount where necessary, but I'm wondering why it does it.

 

Just as a thought, - sometimes I forget to turn on the Centre tank fuel pumps until I see the "fuel in centre tank" warning, and it might have happened when I switch these pumps on.  I don't know if that has something to do with it.

 

I have the flight going at the moment and don't want to fiddle around with it during this time.

 

It's no big deal and easily correctable but I thought I'd mention it.

 

Regards

John khan

 

PS.  The "Fuel Disagree" message does happen on the first flight with mine aswell. (Just saw the other post).

 

PPS.  I'm also getting a yellow "CAUTION" on the Master Warning that does not go off.  There are no issues that I can see, and I've checked the "Siren Reset", - or whatever it is in the equipmenbt page and it is ON. This warning stays on all flight but doesn't seem to affect anything else. I have alsso turned off the crew alert warning.

Share this post


Link to post
Share on other sites
Help AVSIM continue to serve you!
Please donate today!

The permanent caution is caused by a bug when using the cold and dark panel state.

 

The fuel disagree bug may happen on the 1st flight for you but it's the second flight if you load a panel state. So for now don't use the cold and dark state and enter a manual fuel quantity until after both engines are started then delete the manual entry and then confirm your V speeds

Share this post


Link to post
Share on other sites

Thanks, but I don't use the cold and dark startup, I use the 'previous flight' state, and try to remember to shut everything down to an APU running and ready situation.

 

John

Share this post


Link to post
Share on other sites

Now 1800 nm. into the flight and there are red and yellow warnings in the master caution and no way to turn them off.  there is still nothing wrong with anything.

 

I did not use the cold and dark start, this is the first flight today.  This is not good enough.

Share this post


Link to post
Share on other sites

 

 


I use the 'previous flight' state

 

That's the problem.  See the issue tracking thread.

Basically, even though the issue tracking thread mentions the fuel issue between two flights, the previous flight state is essentially that: a flight after a previous flight.  There is a QRH procedure to resolve it in a minute or two.  Click CHKL on display control panel when the error is on the EICAS.

 

 

 


Now 1800 nm. into the flight and there are red and yellow warnings in the master caution and no way to turn them off.

 

One of a couple things could be wrong here:

  1. Crew alertness monitor - if you don't touch the plane every once in a while, it will sound an alarm.  In order to silence this, you need to interact with the plane.  The easiest way to do this is to periodically adjust the heading bug to your current heading.  You will see "PILOT RESPONSE" on the EICAS when the CAM is yelling at you.
  2. The panel state bug.  The cold and dark panel state has an associated issue with not being able to reset master caution/warning panel lights.  While you state that you're not using the cold and dark state, it could just be a generic corrupt panel state.

Share this post


Link to post
Share on other sites

It's not the previous flight state per say that's the problem.

 

Before engine start, the FMC takes the fuel level from the probes in the fuel tanks. At engine start, the FMC takes this fuel level as a baseline and, as fuel flows to the engine, it subtracts the fuel burnt from the baseline level measured at start (this allows the pilot to compare the calculated fuel with the fuel measured in the tanks, allowing easy identification of fuel leaks). This can be seen on PROG page 2 and is shown as TOTALIZER and CALCULATED fuel levels (these should normally match).

 

There is a bug in the 777X at the moment where the fuel used figure (also shown on PROG page 2) is subtracted from the CALCULATED fuel level at engine start, before it's reset, leading to the erroneous insufficient fuel message.

 

PMDG are aware of this bug and is scheduled to be fixed.

 

In the meantime, a work around is to go to PERF INIT page after engine start, manually enter a fuel figure (doesn't matter what), then delete it. This forces the FMC to reset its baseline.

Share this post


Link to post
Share on other sites

Thanks guys

 

The fuel amounts are not too much of a problem as I found they are easily fixed by inserting the correct fuel amount into the PERF page if the "disagree" message comes up.

 

The alarm problem is the one that bugs me.  I went through all the menus and set them how I thought would help, but it didn't.

 

.

 


Crew alertness monitor - if you don't touch the plane every once in a while, it will sound an alarm. In order to silence this, you need to interact with the plane. The easiest way to do this is to periodically adjust the heading bug to your current heading. You will see "PILOT RESPONSE" on the EICAS when the CAM is yelling at you.

 

I did turn OFF the crew alert system in the menus, even though I could cancel that warning when it came up.  I'll check to see if that has to be done each time.

 

Never mind, we have to wait until the bugs are fixed, meanwhile I will go back to the Airbus and do a few.

 

Is there any panel startup state that doesn't produce problems? 

 

I try to shut down the 777 to a state where the APU is running, ADIRU and Emergrncy Lights are OFF. PACKS are OFF, Somewhat similar to what a new crew would find when they get on to do a flight. 

 

I take the shut down procedures from the manual without going as far as turning the batteries and everything off.

 

John

Share this post


Link to post
Share on other sites

This happens to me, soon as the warning comes up, I go back into the perf page (I think, wherever you punch in the weight numbers), and re-input the fuel load into the fmc and it's all good.

Share this post


Link to post
Share on other sites