Cruising speeds

Hello,
I want an advice from you. When I want to cruise at M0.78 for example how do you know what IAS is that after passing 10000ft so it is M0.78 above FL280? I always have problems with this, do you use some page for this or how do you know that?

Thanks a lot.

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290 is around 0.78 i think

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I usually memorize the speeds. Most of the time M 0.78 is 290-295 KIAS

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Thanks, but is there any page or post on the IFC with these speeds for all planes? There are lists with the mach speed, but I think it would be useful to have a list with these speeds above 10000ft.

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FPLoIF usually tells you the cruise profile for each aircraft

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Just clarifying, you’re asking for the exact IAS Mach speed? If so, there isn’t one because of your current position and speed relative to Mach, which is a function of the environment you’re passing through. The difference isn’t much, 1-3 knots for most short-medium hauls.

The higher you go, the more important it is to know what speed you’re at in relation to Mach. At 10000, commercial aircraft won’t be anywhere close, so an IAS is fine. Above FL280, you’re in an environment where Mach effects can start to cause issues to your plane, so the speed is given in relation to Mach and no longer in knots.

If you’re asking for plane cruise speeds, they’re listed around here and on other pages like SimBrief for different aircraft.

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You can follow it by display screen. It shows all the mach, ias and gs.

Hi!

Check this topic below to help you regarding speeds and fuel burns :)

293kts is M0.78
300kts is M0.80
314kts is M0.84

Those are one ones that I remember.

If you set those then as you pass 28,000ft you’ll be at the Mach you want

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Thanks, I didnt know that.

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@AdamCallow thanks a lot!

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Go to 320 for the 787 to cruise at M 0.85

Doesn’t for me. How do you get that?


It shows up like this

The A320 family’s cruise profile. 250/290/78 is more accurate in IF

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This is just one chart, there are other variables, but you don’t really need to know the exact IAS above FL280. (Chart is for the B738):

PH0jB

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