Fuel gauge mystery

I did a flight earlier this week and noticed that even during cruise my ETE to destination was red obviously meaning I didn’t have enough fuel to gather there, this made me worried an difference tried a bunch of stuff trying to rid of the red numbers. Surprisingly though when I land I immediately checked the fuel on the aircraft it show 5 hours of fuel remaining. My question is why was there red numbers if there was over enough of fuel on board

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You loose allot of fuel during climb, thus showing the gauge red as you use allot of power and fuel for climb ;)!
Warm regards,
305.

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I understand but usually it goes away during cruise but this it didn’t. This flight was no different to any other

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Can you reproduce this and provide some form of record like screenshots and recording? It would be nice to have some data here like Aircraft, Route, FPL and so on.

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The red is based on your flow rate at cruise. You could have been too low or too high and your speed be off.

It is more of an estimate, not exact.

It also helps if you share which plane it was with.

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The route was quite long ( KLAX to OMDB) unfortunately I don’t have any clips but I swear it just a normal flight that I’ve done before with no issues. It was an A380

It could have been due to a large number of factors. Alt, wind, weight, etc. It turns red within a variance of the fuel so you could have been on the edge, hard to tell.

All of our replies are just guesses that we are throwing out because there’s now way to pinpoint exactly what it was. You landed safely so thats all that matters.

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The reason for showing 5hrs on the ground is simply because the engines were running at a far lower n¹ than when they are in the air. I’m sure if you had (but I don’t recommend) cut the engines mid flight you would have gotten a similar results. Just remember your aircraft uses a lot of fuel at takeoff and climb, and a bit more in the cruise. As @Chris_S said, at least you landed safely

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Ya, I suppose thats all that matters. Although I gotta be honest, it really sacred me. Putting so much time into planning and then being told you won’t make it, is not my cup of tea. Really gave me the shivers when I saw it

Like others have covered, your fuel burn will be the greatest during your initial climb and early phases of cruise because you’re at your heaviest weight. It requires a great deal of thrust to keep your aircraft aloft at these weights and at a speed your demanding. Because of this, you have your power set higher to maintain a given speed.

But do not worry. You might be showing that you’ll be a few hours short on fuel to your destination shortly after establishing cruise. As your aircraft burns fuel, you are reducing the weight of the aircraft. Because you are at a lesser weight, this requires less thrust to keep the aircraft aloft at your given speed.

Take this example: I departed on a flight that I know is 15hrs in length. But in the first 1hr of the flight, I might be showing 12 hrs of fuel at my current fuel burn/flow. This is because I’m still heavy. As I near my destination, I notice that I’ve got 4 hrs of fuel left. That’s at least another 4 hrs of flying past my destination.
Reasoning: Aircraft is lighter and as a result fuel burn lower because less thrust is needed to keep the aircraft flying at said altitude and speed.


There are a great deal of tutorials that cover “Fuel” related matters in the #tutorials section of the forum. These have been of help to others and I hope these can help you as well.

Fuel planning is discussed in this topic as well: 👇🏼

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Thank you, really appreciated

This same thing happened to me today! It showed red on the fuel and I actually ran out and my engines cut so I landed on the water and when I went to the fuel section in the menu it showed I had 3-4 hrs worth of fuel left. And whats even weirder is that I was flying the same route except the other way (OMDB - KLAX).

Look up the the real life flight time and add 1.5-2 hours of fuel to that

I’ve also had Fuel problems with the a380. In the one flight I flew with it, all fuel drained from the main tanks, none from the tail tank. I had about an hour of Fuel left but the status bar still said I was at like 50 percent load

Fuel isn’t the only load factor on the aircraft.

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On the ground, the fuel level is just how long your engines can run without applying any thrust.

Yup, but I was still over MLW with only an hour of Fuel to go. Had to have been a glitch

What was your speed during climb, what I have found is climbing at a quicker speed saves more fuel. Once above ten thousand feet, try increasing youre speed to 290 knots and above.

Without any information, we can’t possibly know.

No screenshots, no specific information regarding initial fuel, fuel burn to that point, fuel burn at that point, aircraft load, speed, etc, there’s nothing upon which to base any analysis.

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I can say that I definitely have a good tail wind throughout the flight except the last hour or so. My vertical speed started out normally at +2500 and after ten thousand feet +2000 to cruise. My speed during this climb was practical, no different to any other. One I found out was to put my speed at the max, just below the speed restriction this helped that away the red numbers but obviously I didn’t feel very proud of myself as the N1 was above 100%