Speed limit?

Hello I need a question answered. Im flying at 348kts and another flyer is at 440kts at the same altitude? I would be given speed violations after speed violation however the other flyer is at 450kts. Please assist?


You’re looking at GS for those other pilots. Your speed is IAS. The ground speed will be significantly higher due to winds and the like.


What you are seeing is the other pilots Ground speed, which is something different than what you’re referring to as your own speed, which is displayed in airspeed (on the left part of your HUD).


You are seeing his GS, you are seeing your Airspeed.
GS > Airspeed

So the max air speed is 350kts at highest altitude? I find that a bit slpw especially for long distance flying. What are your views?

No. The max speed is based on the aircrafts specified maximum MACH speed. And going 350kts at lets say 34.000ft will most likely result in you breaking the sound barrier. And last time i checked we don’t have the Concorde ;)


Your airspeed is not the same as ground speed. If you cannot go any faster and you are at the same altitude then you are probably going about the same speed.

I think someone should make a in-depth explanation thread about IAS & GS to make it easier to understand for people new to the concept.


Just to show you what i mean:

As you can see on the picture, i’m at FL340 which is a normal cruise altitude. I took fighter and accelerated to 350IAS. That speed brings me to Mach 1.07. No commercial jet in the world flies at that speed. Except for the Concorde which we all know are not in IF nor is it in service anymore.


My views are that physics exist.

Commercial airframes aren’t built to go faster in real life.

What is the last commercial flight you’ve been on where you broke the sound barrier?


I’ll take it on tonight, and post later so everyone knows the difference between Indicated air speed, True airspeed, and ground speed


Max airspeed should be about 320IAS max for commercial jets on IF. It equates to m.85 once at cruise.


Or less, when I fly FL350 the airspeed is 290kts

The higher you fly the less dense is the air. This means that there is less drag associated to push back against the power generated by the propulsion. For a prop you would also lose the ability to churn through the air since the air is less dense as you climb. For a jet engine your power would also lessen so you reduce your thrust. There will be a sweet spot depending on the air frame and propulsion method. Bottom line, typically the higher you fly the more fuel efficient your plane will be up until the air becomes too thin to provide this yeald. Your air speed per say has not increased however your drag has reduced thereby providing a relative increase in ground speed.

N.B. Ground speed is relative air speed PLUS winds aloft (which could be +/- 200 kts)


The Cessna Citation X cruises at approx 527 kts GS, 280 kts IAS at 35,000 ft which is M.90-.92 depending on the wind.
290 kts IAS is red line.
Currently the fastest civilian aircraft in use.

Here you go everyone Understanding different types of speeds

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@Khaleeb_Ali definitely check out Brandon’s post above 👍

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