Your Guide to Fuel Burn and Cruising Altitudes in the New 777 Family

REWORKED 777 CRUISE PROFILES

20.2’s Open Beta is upon us, and clearly the main attractions are the reworked 777 models. In this tutorial, I’ll go over the ideal cruise altitudes for the 777-200(LR), 777-200(F), 777-300(ER), and our old friend, the 777-200(ER), so you can get maximum range out of them. Follow these, and you’ll go far (literally).

These four aircraft have three things in common: big power, big range, and big penalties for choosing the wrong cruise altitude. They’re rockets when light, but tanks when heavy, and cruise much lower than you might think.

How to Read This Guide

A red cell signifies a cruise altitude too high for that aircraft at that weight that carries large fuel penalties.

An orange cell signifies a cruise altitude a little too high for that aircraft at that weight that carries smaller fuel penalties.

A green cell signifies a cruise altitude appropriate for that aircraft at that weight going East, maximizing fuel economy.

A blue cell signifies a cruise altitude appropriate for that aircraft at that weight going West, maximizing fuel economy.

A grey cell signifies a cruise altitude that is too low for that aircraft at that weight that may or may not carry a small or large fuel penalty.

An asterisk (*) signifies a cruise altitude that may carry a caveat - read the notes before using.

Fuel Capacity is simply the maximum fuel that can be loaded onto that aircraft.

Game-Estimated Maximum Flight Time is the flight time that Infinite Flight tells you when you fully fuel your aircraft.

Theoretical Maximum Flight Time is the flight time calculated from these numbers that is theoretically possibly, waiving all IFR altitude rules and reserve fuel rules.

Practical Maximum Flight Time is the flight time calculated from these numbers that takes into account a 90% passenger and 75% cargo load (75% cargo load only for the Freighter), IFR altitude rules, and reserve fuel rules.

Flight Profiles are the ideal sequences of cruise altitudes for an aircraft at different loads.

Disclaimers

Disclaimer I: Numbers have not been tested on an ultra long haul yet. All numbers are from solos and may or may not hold up in practice. Be a proactive pilot.

Disclaimer II: When setting autopilot to the 777 family’s economy cruise speed, M 0.84, they tend to cruise 0.83 when heavy. Setting the autopilot to 0.85 remedies this, but will result in a very, very slightly increased fuel burn. These tests were conducted setting the autopilot to 0.84.

Disclaimer III: To keep it simple, I only took measurements every 10% load. If there were huge drops in fuel burn over those 10% I tried to take them into account when determining the climb profile.

Disclaimer IV: I am assuming linear rate of change of fuel burn between 10% increments. This is likely not the case, but it should be close enough.

Disclaimer V: Numbers in charts are in pounds. Works all the same for kilograms just different numbers.

777-200(ER) | Old Faithful

First of four, with an impressive range and predictable fuel burn.

Figure 1 - 777-200(ER) Fuel Burn Chart

*Theoretically, it is best to go to FL340 at 30% load, however, if you expect to fly well into 10% or 20% load, it may be worth it to step up to FL360 at around 27% or so.

Fuel Capacity: 307,492 lb or 139,476 kg

Game-Estimated Maximum Flight Time: 20hr 55m

Theoretical Maximum Flight Time: 27hr 59m (Tested 27hr 41m)

Practical Maximum Flight Time: 18hr 46m (Eastbound) | 19hr 04m (Westbound)

Flight Profile (East): FL310 (100%-51%), FL330 (50%-31%), FL350 (30%-21%), FL370 (20%-0%)

Flight Profile (West): FL300 (100%-51%), FL320 (50%-31%), FL340 (30%-27%), FL360 (27%-11%), FL380 (10%-0%)

Figure 2 - 777-200(ER) Fuel Burn Graph

777-200(LR) | Long Range King

It lives up to its name. This aircraft is the definition of Long Range.

Figure 3 - 777-200(LR) Fuel Burn Chart

*Stepping up to FL340 at 50% load is not the most efficient routing, but if you’re one who would like to not skip flight levels and go straight from FL320 -> FL360, you can make a brief, 1 hour stop here, it won’t hurt that much.

Fuel Capacity: 325,349 lb or 147,576 kg

Game-Estimated Maximum Flight Time: 22hr 07m

Theoretical Maximum Flight Time: 33hr 14m

Practical Maximum Flight Time: 26hr 27m (Eastbound) | 26hr 40m (Westbound)

Flight Profile (East): FL310 (100%-51%), FL330 (50%-41%), FL350 (40%-33%), FL370 (33%-0%)

Flight Profile (West): FL300 (100%-51%), FL320 (50%-41%), FL360 (40%-21%), FL380 (20%-0%)

Figure 4 - 777-200(LR) Fuel Burn Graph

777-200(F) | Fuel Monster

This one’s incredibly thirsty for Jet-A. Those packages must be really heavy.

Figure 5 - 777-200(F) Fuel Burn Chart

*At 10% load, it’s technically more efficient to go to FL350, 360, 370, or 380, but you would have to have very little cargo onboard, and for that reason these aircraft usually don’t exceed FL350 in real life.

Fuel Capacity: 319,670 lb or 145,000 kg

Game-Estimated Maximum Flight Time: 17hr 56m

Theoretical Maximum Flight Time: 20hr 55m (Tested 20hr 57m)

Practical Maximum Flight Time*: 11hr 35m (Eastbound) | 11hr 38m (Westbound)

Flight Profile (East): FL290 (100%-41%), FL310 (40%-31%), FL330 (30%-0%)

Flight Profile (West): FL300 (100%-31%), FL320 (30%-21%), FL340 (20%-0%)

*The 777-200(F) burns significantly more fuel if you even add a little bit of cargo. If you need to fly longer than 12 hours, you need to load less cargo. At 50% cargo, maximum practical flight time jumps to around 16 hours, both directions.

Figure 6 - 777-200(F) Fuel Burn Graph

777-300(ER) | Well Rounded

Additional capacity over the 777-200(ER), without sacrificing range.

Figure 7 - 777-300(ER) Fuel Burn Chart

*Stepping up to FL340 at 50% load or FL350 at 40% load are not the most efficient routings, but if you’re one who would like to not skip flight levels and go straight from FL320 -> 360 or FL330 -> 370, you can make a brief, 1 hour stop here, it won’t hurt that much.

Fuel Capacity: 307,492 lb or 139,476 kg

Game-Estimated Maximum Flight Time: 19hr 42m

Theoretical Maximum Flight Time: 26hr 22m (Tested 26hr 12m)

Practical Maximum Flight Time: 20hr 35m (Eastbound) | 20hr 27m (Westbound)

Flight Profile (East): FL310 (100%-61%), FL330 (60%-41%), FL370 (40%-0%)

Flight Profile (West): FL300 (100%-51%), FL320 (50%-41%), FL360 (40%-21%), FL380 (20%-0%)

Figure 8 - 777-300(ER) Fuel Burn Graph

Key Takeaways

777s cruise low. None of them like being above FL380, and most won’t like being above FL360 unless very light.

Cruise at M 0.84. 777s don’t like being anywhere else.

Pack a lot of extra fuel flying the 777-200(F). Like four hours extra.

Most of these planes can fly antipodal. They should be able to do any route you throw at them.

If flying overnight, use an altitude which has steady burn throughout a wide range of load percentages. Try not to get into the red cells.

As a side note, the most efficient cruising altitudes in Infinite Flight seem to mirror 777s in real life, which is great.

atisalphablack

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Great tutorial, Andrew. Much appreciated.

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Phenomenal job, Andrew! The sheer detail in here is mind-blowing. I will be sure to refer to this. Thank you for making such a fantastic guide! 👏

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I don’t know what to say other than thank you for making this. I’m sure a lot of us would make use of this a lot more when trying to go for.

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Wow! This very impressive!

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I already know your potato phone was dying on high graphics

Nice shot and tutorial Andrew!

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An interesting read. Good job sir.

Just an idea for the future - it would be interesting to see how these figures compare to SimBrief’s fuel calculations. SimBrief is famous in simulation circles for it’s stunningly accurate fuel burn figures on the majority of their aircraft and using the best flight levels to get the most efficient flight.

But that’s for another day!

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I’m confused as to what the colours and the numbers in the coloured boxes mean?

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It’s one of the first things you see

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Amazing tutorial, this will help me so much! I had now idea how to step-climb unfortunately 😭, and now I know! I’ll be on the leaderboard soon!

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I guess they didn’t change the fuel data for the 77W?
The 77W used to have this 320-370 jump as well. I tested it quite a while ago.
Also, fun fact: the B738 and A330 are the only aircraft in IF I’ve found so far that are most efficient at FL410 when near empty. Everything else I’ve tested maxes out at 370 or 380.

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The leaderboard is mostly people going single engine on the A350 lol
You can go like 60 hours like that

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It was literally 30 seconds and it was already lagging.

That’s actually a really good idea - I don’t ever pay attention to SimBrief’s fuel numbers, but now I’m curious.

Colors are up in the “How to Read This Guide” section, numbers are fuel burn, pounds per hour.

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I only liked this topic because of the introduction image.

jk, thanks so much for making this lit tutorial

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Simbrief LRC does make everything M.84 (at least of the 77L I checked). However there is an exception: turbulence penetration speed is M.82

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all I know about is the 772ER right now, but according to simbrief it typically cruises at FL370 or higher unless extremely heavy (like 75%+). And cost index will occasionally have a significant effect on cruise speed (sometimes simbrief says cruise at m.79 if tailwinds are strong)

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Yeah true, but afaik turbulence doesn’t affect IF aircraft’s fuel economies.

Maybe yeah, but for IF purposes the numbers are slightly different but if you’re like in the mid 50s range cruising at like FL370 isn’t going to kill you.

Yeah that’s fair. According to FD2S, a real 737 pilot, SimBrief was within a few kilos of his airline’s calculated figures for the same route and payload so it’s pretty accurate!

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Amazing tutorial! I’ll be sure to use this next time I fly with the B777!

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this plane beautiful