A350 fuel burn issues

I did a fuel burn test with the A350 at M.85 and found that even with empty weight the best altitude is FL340. Is this some sort of an issue with the fuel burn data?
Also, even weirder, at certain altitudes I found several instances of less weight resulting in higher fuel burn (???)

EDIT: For people saying I am not using the correct weight, FL340 was found to be the best altitude at 150 tonnes (empty is 140).

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Have you made sure that the winds are no factor?

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The further into your flight, the less fuel burn you have because you’ll get lighter. There are also many other factors, like wind, step climbing, takeoff altitude, and others

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The A350 carries a large amount on fuel. It behaves just like the 77L where even at 70% your load keeps you at that FL340 level because of how high it’s MTOW is.

As to the less weight, not flying at the the optimal flight level will result in fuel burn penalty. So if you are flying lower than your optimal flight level you actually increase your fuel burn rate and same with being too high. I forget how high the percentage of the fuel burn penalty is when flying below optimal flight level though.

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I did this on solo with no wind or turbulence

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This is with almost no fuel or load though.

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I suggest try a couple of flights. I took the A350 to FL370 and FL380 in my flights today. No issues.

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I’m confused. When you say you did a fuel burn test, what exactly were you testing?

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It’s burning more fuel than at lower levels. It works obviously.

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I make a google doc with the fuel flow at different weights and fflight levels.

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I meant to say no fuel issues. It burned how much I expected it to burn based on load and altitude.

Wow that’s cool. Can you share some of those docs?

I might share them somehow eventually. The most useful info from it is when to stepclimb actually.
I do have a formula for estimating how much time it takes to burn a certain amount of fuel, but it is actually pretty messy (had to do some really fancy math lol)

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I used FL400 on a 12 hours flight and everything was fine.

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