Is there a speed limit at or above 40,000ft

Hello I am flying a medium haul flight 4 and a half hours and I just climbed up to FL400 my speed is 240 or m0.87 and I was going to increase my speed and I was wondering what speed I could go where I wouldn’t break get any speed violations?

I don’t know the actual speed limit for that altitude, but I am pretty sure if you fly at or below 0.85, there won’t be a violation.

First of all, I’m not aware of any commercial aircraft that flies at M 0.87. Second, I think it’s FL430, correct me if I’m wrong.

Stay below the red dots on your airspeed indicator. Above 10,000 you’re only limited by the simulators VNE (never exceed speed) for each aircraft. (Except fighters)


Lalala… Casually Flying M0.85 at FL410 as of right now… 🤭


787, 747, the list goes on

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I also forgot to mention that I’m flying the 747-400

If you have any doubts, when you enter the “red zone” on the airspeed indicator, you’ll get a warning after which you have 20 seconds to get back below the VNE. So you can test it out if you want to, just make sure you slow down in less than 20 seconds.

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According to what DeerCrusher told me, the Commercial speed for 787 is M0.87 although the typical cruise is at around M0.85

Read our discussion here about speeds of the 787:

I’m flying the 747

The Boeing 747-400 flies typically at M0.85 while the newer 747-8i flies at M0.86 :)

Oh so I should decrease my speed I’m flying at m0.87

Which 747 are you flying right now?

Typically… it “can” fly faster though… it’s just not the most economical

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-400 series

The Boieng 747-400 usually cruise at the speed between 0.84-0.85 mach, the MMO for Boeing 747-400 is 0.92 if I remember it right.

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The 747-400 can also be flown at .86 but it normally flies at .85

The -8i flies at .86 though :)

Then you may go for Mach .85

It can fly faster and if you look at the chart Deer posted, the economical cruise speed for both the 747-400 and -8i is: Mach 0.86

I personally fly both of the 747 models (-400 & -8i) at Mach 0.86 for all my flights.

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Think I’m also having trouble with the autopilot