Mach speed question

How fast is M.85 in knots in a 777-300? I’m doing a flight tomorrow and I need to know the speed in knots.
Thanks!😀

The 777 doesn’t cruise at .85 it cruises at .84 which in IAS would be 313-315 i believe. You can also put in the mach speed once you pass FL280 but make sure to speed up to at least 300 or you’ll struggle and potentially stall at FL280

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Ok, thanks!

Also to confirm the mach speed needed I just do a simple search of “777 cruise speed mach”

Also, if you’re referring to how much knots the ground speed will be, that is highly dependent on the wind conditions.

0.85 I’ve found is about 320kts (ias).
Though as @ThomasThePro said the 777 does 0.83-0.84 (on average). The 747 (all versions) do 0.85, the 787 does 0.85, the DC-10/MD-11 does 0.82-0.83, the A330/40 does 0.82-0.83, the 767 does 0.78-0.82, the A350 does 0.86. Just figured clear any confusion.

777 do M.84.
M.84 is average flying speed for that aircraft!

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https://www.metric-conversions.org/speed/mach-to-miles-per-hour.htm[quote=“Captain_Cobb, post:1, topic:391438, full:true”]
How fast is M.85 in knots in a 777-300? I’m doing a flight tomorrow and I need to know the speed in knots.
Thanks!😀
[/quote]

@KindaTartySliceOfPie… MaxSez; GOOGLE is your friend…

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Like others have sort of mentioned, your Indicated Airspeed will differ according to atmospheric conditions. Once over FL280, your indicated airspeed will decrease because the air gets thinner the higher you go up.

Now if you want a climbing profile to get to .85 you would do 250/320/85. First number is your airspeed below 10,000 feet. Second number is airspeed above 10,000 feet, and as your ascend over FL280, you will automatically convert to Mach and that should be at .85.

Hope this helps

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