Reach high altitude with high speed

Hi. I would like to know how to reach high altitude with high speed because when I’m at 35000ft, speed is around 280kt and it can’t go higher.
Thank you all.

That’s normal.
When two aircrafts are cruising at the same KIAS, the one that flys higher is faster then the one that flys lower.
Take a look at your GS ;)

Oh so that’s normal, even if the KIAS is not really high, the aircraft is still faster than another one that cruises lower.
Thank you !

But is it normal that speed decreases ?

At high altitudes air density cannot allow the wings to generate lift.
That’s the reason why the aircraft slows down… And one of the reasons why AF447 crashed into the Atlantic Ocean in 2009…

I understand now, thank you !
I didn’t know that it was one of the reasons…
Can you tell me why “exactly” if you know more please.

That and the pilots weren’t properly trained and did not handle the situation properly!

I see I see ! Unfortunately !

Read the “Mach” speed. Depends on the aircraft, but if you’re cruising between M 0.75 and M 0.83, you’re fine-Airspeed doesn’t matter.

Start a flight, fly up to 28,000 ft., set the autopilot speedfor any one of the Mach speeds above (Bigger aircraft=Faster cruising speed) and watch.

Best, Boeing707

I will do that. Thank you.