777 200 & 777 300

When flying 777s I cannot get my speed to stay above 300 knots. I’ve tried flying without passengers and cargo and lowering fuel levels but it doesn’t make a difference. Any ideas?

What altitude are you at. Your speed will decrease as you get higher. Your ground speed should still be high.

At 37,000 feet you are going to struggle to be over 300 air speed.


The speed limit above 30000 feet is usually around 300 knots before you need to slowdown due go overspeed…

When passing 28,000 feet (FL280) the aircraft enters in Mach mode meaning it should say 0.80 or 0.83 either way the airspeed decreased but your ground speed maintains. If you get what I mean.

This tutorial will help you with reading the types of speeds!

Don’t forget about the wind. That also plays a role in your speed above FL300.

20,000 ft is when it drops below 320 kn

Yes, this is normal. It also depends on what your vertical speed is too.

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What is the Vertical Speed?

What do you suggest for VS?

It depends what you had as a VS when it was happening.

Have a look at the #tutorials flight section for some great tutorials on how to fly. We cant give you a number as you need to understand the basics first and it varies.

  • Airspeed decreases as you get higher.
  • As you get higher, your vertical speed or angle of climb may need to be reduced in order to hold speed. This varies depending on which aircraft you are in, weight, wind, etc.

What do you mean like it says overspeed

Every plane has a speed limit. Red dots next to the speed tape in the HUD. As you get higher, the speed limit lowers gradually. Do a flight next time and pay attention to the speed tape dots.

The higher you go the lower the air density thus the higher your mach number but the lower your airspeed. (mach is your ‘percentage’ of LOCAL speed of sound) Flying a fixed ‘mach’ number in the climb will lead to you stalling as the IAS decreases with altitude (.65 for example at sea level is 430kts! but .65 at 36000’ will drop you below the stall) conversely a fixed ‘mach’ number in the descent will lead you to overspeed. (.85 is 561kts at sea level!)

Hence you will have 500kts + ground speed but 280 kts airspeed. Thats why we like to fly higher!

The overspeed tape on the ASI is there to warn you of the onset of supersonic stall/shock and transgression into aerodynamic loads that the aircraft is not designed to accept. In the real aircraft (777) the flight system primary protections will kick in when you transgress into the red tape by more than approximately 15 kts.

Have a look at the aerodynamic effects of altitude on speed in aircraft and it will help you.

Good luck!


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