PMDG777 Fuel Quantity Decrease during cruise

[pcubine 143]

There is a fuel leak option in the failures menu. PMDG SETUP>AIRCRAFT>FAILURES>FUEL>PROGRAMED>fourth item on page 2 of 5

[downscc 1,327]

Be real nice to compare fuel flow rate for the engines with totalizer changes.

[PinkPony 171]

Guys, by looking at his FUEL TOTALIZER on the EICAS, and running a 60 second timer, it is decreasing by over 300kgs/minute. Thats 18,000kgs/hour.

 

That immediately alerts me to a potential FUEL LEAK 

 

Robin, First thing you need to check is the following: (you said this is only occurring with -BVD)

Load up -BVD and the same panel state you did for your AMS-CAI-AMS flights.

I need you to check MENU > AIRCRAFT > FAILURES > FUEL > and check if there are any failures active or armed within the FAILURES > FUEL menu?

 

It is possible that you have the FUEL LEAK failure or something similar active within your pane state, which explains 18,000kgs/hour of FUEL TOTALIZER DECREASE.

 

Also make sure you check the main FAILURES menu. It will tell you what aircraft FAILURES, if any are active. Please tell me which, if any failures are active! Also, check for armed failures and also check the service based failure menu! Anything programmed to be active or armed there?

 

Please check this on the ground and once you are in the air. It may be set to be armed on the ground and once you are in the air the failure may be activating if it is time countdown based. 

 

Just to be clear, this is 100% not a missing or incorrect RTE winds issue. 

 

Something is causing your fuel quantity to decrease at ~18,000kgs/hour. That is more than twice the normal /hour burn of a -300ER your weight range of 240-250t. You definitely need to check your FAILURES menu. Maybe make a video of you going through those menus? 

 

Guys, I forget, are FAILURES saved within the panel states or the config.ini files?

 

[Robinnn 13]

I would love to check that but my plane to Turkey is leaving in a few hours. I will be back on the 24th of June.

 

It could be a fuelleak but I thought a fuelleak is also visible from the outside?

 

Maybe not.

Thanks for thinking with me. I report when I'm back.

 

Robin

[downscc 1,327]

<<Guys, I forget, are FAILURES saved within the panel states or the config.ini files?>>

 

Failure information is saved with the panel in one of the two files that the 777 uses for panels.

 

Again, it might not be a leak.  Say for example, the engine fuel flows are normal but consumption is high then either leak or OP is using an add-on that interferes with the PMDG simulator as cautioned against in the Introduction manual.  Still waiting on data.

[Kaarel Hauk 0]

Hi guys,

 

Having the same issue both with -200 and -300. In my case the aircraft burns more than double amount of fuel (approx 11700kg/h, tested with -300) as of my last flight. Initially I thought it was a planning error on my part which it wasn't after double-checking and then suspected a simulated fuel leak which would have been fine if it would not happen again at the moment besides none of the failures have been armed/activated. Fuel insufficient alerts and fuel reloading in-flight are a reality. Don't get me wrong-I have nothing against diverting per se but when flying in Vatsim to a destination with ATC available for only an hour more, I'd like to reach it. 

Aircraft state in cruise is as per checklist. No dropped gear, extended spdbreak or flaps.

 

I would really appreciate it if someone could help me on this.

[downscc 1,327]

More information please.  Are the fuel flows indicated on the EICAS consistent with the fuel consumed? Are you using any add ons that might modify the fuel on board?

 

A description of the flight including weights, released fuel, planned remaining fuel and actual numbers would be helpful.

 

There is not a bug in the aircraft. In order to help figure out what is going on it helps to know what you're experiencing in greater detail.

[vr-pilot 11]

In my case the aircraft burns more than double amount of fuel (approx 11700kg/h, tested with -300) as of my last flight.

Reminds me of incidents like Air Canada Flight 143. Taking lbs for kgs practically reduces the range by 50%.

I don't think it is the case here, but it is nevertheless always a thing worth to remember as RW shows...

[Nuckingfutz 1]

It's like Bryan says, all in kgs. Based on the flight route, weights, FL, wind predections etc, the plane thinks (at departure), that there will be (e.g.) 5200 kgs of fuel left at destination. As the flight progresses, the plain recalculates a lesser value. 

 

It might be that Active Sky uses other wind data then PFPX (in of 10 cases). PFPX provides the wind aloft data for the fuel prediction during flight (only once, at departure if I am not mistaken). Active Sky provides the actual winds that are encountered during flight. In theory they should be identical, but perhaps this is a clue for this mysterious fuel disappearance. Question of course is, if potential differences in wind can explain this excessive fuel consumption.

 

The fact that the issue is happening only 1 in 10, seems to indicated that Bryan is doing nothing wrong. Otherwise, the issue would appear 10 out of 10.

[vr-pilot 11]

The fact that the issue is happening only 1 in 10, seems to indicated that Bryan is doing nothing wrong. Otherwise, the issue would appear 10 out of 10.

Mmh. Fuel consumption almost twice as high during CRZ could also be caused by an OAT simulation error.

[PinkPony 171]

Hi guys,

 

Having the same issue both with -200 and -300. In my case the aircraft burns more than double amount of fuel (approx 11700kg/h, tested with -300) as of my last flight. Initially I thought it was a planning error on my part which it wasn't after double-checking and then suspected a simulated fuel leak which would have been fine if it would not happen again at the moment besides none of the failures have been armed/activated. Fuel insufficient alerts and fuel reloading in-flight are a reality. Don't get me wrong-I have nothing against diverting per se but when flying in Vatsim to a destination with ATC available for only an hour more, I'd like to reach it.

Aircraft state in cruise is as per checklist. No dropped gear, extended spdbreak or flaps.

 

I would really appreciate it if someone could help me on this.

 

Can you upload a youtube video from the cockpit and share?

 

Pop-up the lower EICAS showing the ENG page so that I can takea look look at the actual fuel flow (FF) per engine and also pop-up the FMC progress page 2/2 so that the SAT temperature is visible.

[bc48 0]

Hi all,

Great news from me. I experienced the problem today again and I deicded to experiment a little. I waited to see if the fuel would decreasea large amount in 30 minutes and it did (as expected). Since I have FSUIPC's autosave enabled, I decided to restart my simulator and load the flight back up to my last saved location. The fuel was stable after the restart. The fuel burn wasn't huge anymore. As of right now, the predicted fuel at destination has been the same value for about an hour now. Overall, I have concluded that it has something to do with simulation error. The next time you guys experience this and have autosave enabled, try this method.

Thanks,

Bryan Cheung

[Derpinson 0]

I had the same problem, fuel decreasing over a short period of time.

 

I tried what bryancheung said, let FSUIPC autosave and restart P3D, and try it again. After reloading the sim, I updated my winds aloft in the FMC, and after 2 hours of flying from VYYY - VIDP, the fuel at VIDP is remaining the same for the 2 hours. 

 

I can confirm this works. Thanks Bryan. 

[funkyj4ever 2]

I had a problem with lbs and kg. I fixed it by going into settings and change theme to kg or lbs and back. And start a new flight. That fixed it for me

 

greetz

jordi

[guirka 0]

I had the same problem with my PMDG777.  I don't use FSUIPC. For me was fixed adjusting the cost index, I did it while flying, I changed it to 6, and the fuel drop stopped.