Excessive Fuel use

[007]

I flew from TBPB to EDDL last night and ran out of fuel about 2 hours into the flight.  The aircraft had plenty of fuel (I loaded over 51,000kg per simbrief) so I know it wasn't an issue with not having enough fuel to make the journey.  Additionally, I turned the APU off after the second engine was started so it couldn't have been the culprit in starving the engines of fuel.  Unfortunately I wasn't sitting at my desk when it happened - I returned to my computer moments before the plane struck the ocean - I didn't have much time to assess the problem before impact however I did notice that both engines were off, the aircraft was in a stall, and the fuel tanks were empty.  Anyone else experience something similar to this?  Maybe I screwed something up?

[Mathijs Kok]

No idea at this moment, when you do a new flight check if the fuel flow is higher than expected.

[DaveCT2003]

That is the same bug the A320 has... every once in a while the aircraft just quits playing.  It's been under investigation for a few years now.  Thankfully, it's very rare.

 

[Secondator]

I wonder if this is related to the power loss issue which we figured out could happen at least due to the Carenado Aircraft CRM? Do you have any Carenado aircraft installed? Were you flying online when this happened?

[hilkiah]

Hi I'm doing a flight NSTU/AYPY :

NSTU/05 DCT TUT DCT RM DCT GB DCT GNY AYPY/32R

Simbrief suggested 44.8 kg of fuel (the A330 fuel/load planner actually suggested a lot less for zfw 160.0 kg).  Anyway I fueled up at NSTU (44.8kg) and I am now 1242nm away from my destination and about to run out of fuel.  I'm cruising at FL380.  Is there any way I can add fuel mid air?  I tried adding fuel from the P3D Vehicle -> fuel menu but that doesnt' work.

 

Hilkiah Lavinier

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[Delta_Who]

Had a similar issue yesterday where my aircraft was consuming 34 (17 per engine) tonnes per hour.

 

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[davidnorfolk96]

i'm experiencing this too. the thing is drinking through fuel. the EFOB decreases insanely quick 

[hilkiah]

So is there a way to add fuel mid flight?  Right now I'm gliding to the sea floor 😞

[Mathijs Kok]

Okay we will try this ourselves.

[Delta_Who]

3 minutes ago, davidnorfolk96 said:

i'm experiencing this too. the thing is drinking through fuel. the EFOB decreases insanely quick 

 

That's another thing I've noticed too... inconsistencies in EFOB calculations.

 

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If we take the image above, I've passed ALLRY with about 23 tonnes on board. MCDU still has not updated and is predicting 15 tonnes.

[davidnorfolk96]

Loaded her up with 35.000kg of fuel, EGKK-GCRR, as you can see it's used 10.000kg already but the EFOB say's 4.3 left in the tanks on arrival. however 20 minutes ago it would was saying 6.4 or something 

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2 minutes ago, Delta_Who said:

 

That's another thing I've noticed too... inconsistencies in EFOB calculations.

 

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If we take the image above, I've passed ALLRY with about 23 tonnes on board. MCDU still has not updated and is predicting 15 tonnes.

i had mine go into the minus yesterday, i used the fuel simbrief told me to use plus 5000kg on top of that too 

[Delta_Who]

2 minutes ago, davidnorfolk96 said:

Loaded her up with 35.000kg of fuel, EGKK-GCRR, as you can see it's used 10.000kg already but the EFOB say's 4.3 left in the tanks on arrival. however 20 minutes ago it would was saying 6.4 or something 

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i had mine go into the minus yesterday, i used the fuel simbrief told me to use plus 5000kg on top of that too 

 

Mine is predicting -0.7 at EGCC atm. Fingers crossed we don't end up in the atlantic ;). Although at my best guess, we should still have 6-8 tonnes when we land.

[Mathijs Kok]

Keep in mind that predictions on an A330 are just what the term states, predictions. We have seen them off by a lot in real aircraft.

[007]

5 hours ago, Secondator said:

I wonder if this is related to the power loss issue which we figured out could happen at least due to the Carenado Aircraft CRM? Do you have any Carenado aircraft installed? Were you flying online when this happened?

i do have a carenado aircraft installed (the ATR). I was offline when it happened. Should i uninstall my ATR?  I never use it anyway....it won’t be a loss to me. 

[hilkiah]

Update....I'm still alive!!  I was able to add fuel to the plane though the fuel tanks all show 0 fuel available, the FOB shows something else.  I am back at cruise and hopefully will be able to land this bird.  I used the Vehicle menu -> Fuel and Payload option.

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[hilkiah]

btw, I'm using GSX2 (enabled in MCDU) and I also had the checklists enabled in the MCDU...not sure if that matters to be honest.

[PMSoares]

Gentlemen... I have made some long haul flights, and the  Aerosoft A330 FMGS seems to have the following issues. 

 

When fuel is transfered from the wing tanks to the triom tank, the FMGS considers that this fuel is "lost" and thus the fuel predictions which were comfortable on dispatch, suddenly become low or even negative. Once the trim tank fuel is pumped back to the wing tanks, the EFOB on destination and altn airports start to rise. 

 

The fuel calculation algorythm must be improved. 

 

Actual fuel consumption is more or less realistic, according to some fuel flow tables that I have from the A330 FCOM. Actually I'd say the plane is burning aroun 10% less in crise than what's supposed to, according to the FCOM. 

 

Fuel calclation function in INIT B page is not working. Nor is the Wind Data request. In very long flights, even a minor Wind variation can yield to large EFOB variations. 

 

Always use the primary method (which works from the Piper Cub to the A380) for fuel calculation: Distance divided by Groundspeed multiplied by your fuel flow is the required amount to reach destination. 

 

Happy flights! 

 

Paulo M. Soares

[ComSimPilot]

4 hours ago, Mathijs Kok said:

Keep in mind that predictions on an A330 are just what the term states, predictions. We have seen them off by a lot in real aircraft.

 

Mathijs, with all respect I don't think just because the real aircraft can sometimes show weird things, this is a proper answer for a bug we all experience. I don't think the real aircraft predicts negative fuel on destination in the middle of the cruise. That is way too off to be realistic. 

[ComSimPilot]

Here is a picture.

 

The good news is that Simbrief prediction is very close to FOB. 

 

The bad news is that the MCDU is completely off. You can see that even the previous waypoint shows less fuel than the current FOB, and the prediction for the way-point which is 1 nm away is 7.8 tons less. I don't think this happens in the real aircraft.

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[Delta_Who]

5 hours ago, ComSimPilot said:

Here is a picture.

 

The good news is that Simbrief prediction is very close to FOB. 

 

The bad news is that the MCDU is completely off. You can see that even the previous waypoint shows less fuel than the current FOB, and the prediction for the way-point which is 1 nm away is 7.8 tons less. I don't think this happens in the real aircraft.

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 Yh exactly. If we're talking 100-500kg off, that I can understand. In this case, we are literal tonnes off, like the MCDU is not acknowledging current fuel levels or fuel burn at all.

[RALF9636]

vor 9 Stunden , ComSimPilot sagte:

Here is a picture.

 

The good news is that Simbrief prediction is very close to FOB. 

 

The bad news is that the MCDU is completely off. You can see that even the previous waypoint shows less fuel than the current FOB, and the prediction for the way-point which is 1 nm away is 7.8 tons less. I don't think this happens in the real aircraft.

Please login to display this image.

 

Same here. The MCDU values that were initially totally off slowly caught up with reality during the flight and the values were correct when I reached the final waypoint.

[Mathijs Kok]

As said it will be looked at. 

[Mathijs Kok]

Some questions.... We do know the fuel planner is not setting the correct amount, but at this moment we can't see the fuel use to be very wrong. On several EDDF-KBOS flights we get very close to the reports of the real flight in similar conditions.  

 

Is there anybody here who compared the fuel use with ACTUAL flights? Not just with what simBrief suggests? 

 

simBrief offers the Fuel-Factor setting and when we have that at M07 we get results that match the actual flight reports we have.

[Mathijs Kok]

Btw, we love to get some logs for this. During a flight (not too soon after starting) zip up the data folder Aerosoft A330 Professional\Data and post it here. That will allow us to track this down fast.

[cdog]

Im not sure whats correct or if this may help any but I did a short flight yesterday CYYZ-CYUL with the Air Canada 330 and noticed on climb out that each engine was burning between 13000-15000 LBS an hour. So 26,000-30,000Lbs for both. Is this correct fuel burn? I also was landing with way lower than what was planned in CYUL.