Help with fuel

Sorry for the late response, I woke up over Turkey with 2:45 fuel remaining, and an ETE of 4:30, so I stopped in Istanbul for a refuel.

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how much did you load before you took off ? the fuel in tons

He said he had full fuel. I suspect something was off midflight because he shouldn’t have been burning that much fuel.

The most important in this kind of looong flight is to “prepare your route”
Durant the his entire flight, he might had encountered headwinds as calm winds so not alot of avantages to arrive at destination in one shot…
A good anticipation for your futur in this kind of flight is key, while following the recommanded step-climbs very essentials to save range/fuel.

I would like to give a try to your flight in question.

It wasn’t a wind problem, he was just burning 20% more fuel than normal.

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honestly I have no clue if Infinite flight has the same fuel consumption rate for the 787 and 747 as in real life.

My numbers are based of IF measurements

yep, i can see that

I would hope the 747 is not that thirsty in real life but it might be lol

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I may have read through too fast, but I didn’t see where the 6400 or so burn rate came from other than working backward from ETED. But ETED is affected by wind. So if you use ETED with a head wind won’t it make the fuel burn calculation look higher than it actually is?

If the OP can confirm the winds and/or the actual fuel burn read out?

Or did I miss something in this?

I’ve found in general that the ETE-D calculation is very simple, basically current fuel onboard divided by current fuel flow. So none of the other factors - wind, altitude, reduced weight due to fuel burn - seem to be taken into account.

For any long haul flight, it’s best to use any of the flight planning sites. They do take all this into account, and give you a much more accurate picture of your actual flight.

(Given the right flightplan format, some even list, per waypoint, expected total fuel burn and fuel remaining, so you can anticipate if you choose, or compare the real flight against the actual winds encountered.)

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I’ve always had the impression ETED would have to be affected by wind and it would be included in the reading because it is directly calculable at any moment.

I’ll have to set up a couple of solo runs and see if I’ve missed that … it would be nice to be sure

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You can immediately verify it on solo. Get into a steady cruise heading north so the wind direction slider can stay all the way left for a head wind. Set a fixed speed on the autopilot. Then just watch the change in the ETED number as you change the wind speed slider. Of course you have to wait for the aircraft to resettle back to the autopilot speed after each change in the wind.

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Yeah, I had major headwinds all the way from Sydney to Indonesia, I changed my flight plan slightly to avoid even more headwinds over Asia, so instead of flying over Asia I travelled through the Middle East, only added up to an extra 150NM which shouldn’t have made a difference.

So the ETED looks worse because it takes headwind into account. But it will update to a better number when/if you can get to the lower headwind regions.

Not ETED. He said he had 11:30 worth of fuel left, and he gave the amount. So dividing them out gives fuel burn.

I think there’s a misunderstanding with our phrasing in this topic. ETED is affected by winds, but estimated fuel remaining is not. If i have 10,000 pounds of fuel and my fuel burn is 2,000 pounds per hour, my estimated fuel is 5 hours remaining, regardless of wind (77L, FL300, M 0.84, MTOW, 100 knot headwind - 13,200, 100 knot tailwind - 13,200, 0 wind - 13,200). If I have a huge tailwind and my ETED is 4:00, I am going to make it. If I have a huge headwind and my ETED is 6:00, I might not make it. That doesn’t change the fact that I’m burning 2,000 pounds of fuel per hour.

TLDR: winds do not affect fuel burn in any statistically significant way

Sorry, my mistake. I was taking the 11:30 as an updated ETED even though the OP specifically says (which I missed in my reading)

Of course I completely agree fuel burn is not affected by winds in any way.
But I had tested the flight conditions several ways and I just can’t get that high fuel burn number without doing something unrealistic. So something doesn’t add up(?).

Getting the actual fuel burn number at the time would be helpful.

Of course both the ETED and fuel remaining numbers are affected by throttle setting. And the throttle setting changes if there is a rapid enough change in winds, to maintain the auto throttle speed setting against the change. That definitely messes with both these numbers during the transition to settling into the new wind. I don’t know the odds of that happening in this case.

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Oh, I must’ve misinterpreted your messages as well because we’re on the same page. @Altaria55 and I tried flaps, flying super fast, super slow, all of it. The only thing we could do that got us anywhere close was going to MTOW but OP stated he wasn’t MTOW.

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