How do you decide what altitude you’re going to fly at and how much fuel you take?

So when ever I start a flight I always plan ahead to what altitude I’m going to fly at. But it always takes me 5 to 10 minutes just sitting there trying to come up with an altitude to best suit that specific flight and the load. And I either climb to high and stall out or go to low and waste to much fuel then try to climb higher then stall. And I always have to end up taking an extra 3hrs of fuel with me or else I have divert/crash. I always look a flight up on google to see how long it takes but I still end up running out of fuel.

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You should use to plan your fuel and altitude. It’s super helpful!

8 Likes is great. If you’re looking for a free resource though, is a perfect website for it!


As our fellow IFC members have said, Simbrief is an excellent tool to use for flight planning, everything from creation your waypoint that you’re gonna use in your flights to measuring how much fuel you need.
Flightaware and Flightradar24 can both be used to see how real-world planes fly as i’ve said earlier on your other post :)


I just go 30,000ft for flights under five hours. Then I go between 40-41,000ft.


If he wants to strive for realism he’ll have to go higher in many cases (not everytime). I did a 6h flight from OMDB to EKCH today and i climbed right away to FL380 as the real-world one does then 4h in to the flight climb to FL400.

But what you say isn’t wrong. Many time i also break realism and just fly around FL280 to FL320


I usually plan my fuel according to the winds and flight time to my destination. For short haul routes I aim for 1 hour of extra fuel, medium haul 1.5-2 hours extra fuel and long haul 2.5-3 hours extra fuel. Take extra also because of ATC, i have been in a holding pattern and been 30 minutes and been extended downwind because of Heavy traffic. If you have to face a 160-220 knot headwind for 3 hours and at times I have then you might want 3.5 hours extra fuel.


You can always step climb to. On Ultra long hauls I do from 33,000-35,000-37,000 feet for example. Each step happening from 2-5 hours of the flight.


I’ve told him that and he’s currently struggling with speed on higher altitudes. I’m also helping him via PM.
Simple questions that i’m happy to answer. Btw… If anyone interested in helping, do tell me and i could add you to our PM if needed.

Just use Simbrief. I’ve never had any problem with the altitude or fuel miscalculated.

Tell him to use flight aware and just add 2-2.5 hours of fuel for a flight over 7 hours long so it equals 9.5 hours of fuel. No one should ever put in as much fuel for the flight. If a 150 knot head wind comes into play that fuel will be gone.


This is what i wrote to him on our PM. Feel free to notify me of any mistakes i’ve made if there is any.
His question was why KIAS drops when you go higher. And here’s my explanation. I also gave a list of airplanes in the game and their mach speed at cruise.

As you go higher the air becomes lighter. You don’t need as much power the higher up you go. KIAS = Knots Indicated Airspeed, that’s the Airspeed that your seeing on your HUD or that bar on the bottom of your screen will show you that your speed is decreasing as you go higher. It’s natural. Also remember to cruise at right speed as well. And when you climb don’t max out you throttle nor should you max out you throttle when taking off. I power my throttle to 83-86% (N1 = 82-90% approximately, not higher than that).

That seems ok. Yes sure to mention not to go high up at more than 36,000 feet initially when doing a 7 hour flight. He should step climb to get the maximum fuel efficiency. I have tested this stuff out on casual. Yes, he should not go 249 knots below 10,000 feet or try not to go 330 knots till 28,000 feet either. Tell him to stick at 310 knots till 28,000 feet. If flying a 737 he should cruise at around 0.75-0.78 mach and in a 777 or 787 at 0.84-0.85 mach. He needs to look up the cruise speeds for aircraft.

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I myself start of by going up to FL320-360 or higher if the real-world one does that but you Noah, shouldn’t do that right away and do as @Kate_Russell said and not go above FL360 if the flight is any longer than 7h.

So what i’m saying is that you can check up on FR24 or Flightaware how real-world plane flies the route you want to fly, that is only if you wanna add realism to your flight (which i do but not do everytime).
Stepclimb as the tutorial says that i linked to on your previous post.
Speed, well it purely depends on aircraft type, wind speed and its direction and your plane’s weight.

A mathematical calculation that takes not much time should solve your problems :)
It really isn’t that difficult. Before 10000ft, i stay between 200-240 knots. I increase speed from 200 knots to 240 as i’m climbing to 10000ft then i continuously increase speed from time to time till i hit the correct mach speed at the correct altitude which is about when your Airspeed becomes Mach speed, FL300. Then just reach you altitude and you should have right speed.

You can try out to replicate real-world flight on casual or solo, by doing the same stepclimb procedures like IRL and so forth ;)

A320, A321 - Mach 0.78
A330, A340 - Mach 0.81-83
A380 - Mach 0.85
B737 - Mach 0.72-78
B747 - Mach 0.85-86
B757, 767 - Mach 0.80 (i think)
B777 (All of them) - Mach 0.82-84
B787 - Mach 0.84-85


Also watch at which point you descend. Do not descend from 38,000 feet 80 km out, try 150-180 km out depending on head wind or tail wind and make is a gradual descent from -500 to -2,000


Planning your decent is very crucial. You won’t want to do a unrealistic steep V/S 3000ft drop. That’s be crazy, like pitching the nose down 15 degrees 😅

Instead ahead of time, i’d say before you even before takeoff you should be planing when you’re gonna descend.
As @Kate_Russell said, keep in mind that Wind and Weight of your plane will determine a lot on whether you’re able to slow down quickly or not then again which plane you’re flying also matters. Be careful so you don’t rack up any violations during descend and do use of the Spoiler setting them on “Flight” if your spee start to increase during desced and also pitch up a little in that case. Set your V/S on -1200ft instead of V/S -1600 if -1600 was causing your speed to grow.

Descending should be around V/S -500ft to -2000ft at MAX

3 Likes is free… isn’t it?

I am not certain on that. I would need to do some research. Don’t take my word for it.

Yes, it is free to use :)

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My thinking and experience is that the higher you go up the more wind velocity there is (until space) and it still has to move air so the engines would have to work harder to move enough air to keep it airborne but if you stay to low there’s going to be to much air to move but also less wind. But I might be wrong. When ever I get to my cruising altitude and there’s a really strong head wind I try to climb higher but the wind just gets faster and faster.