Speed low

My aircraft speed automatically gets low and even sometimes it starts stalling above 32000ft

This is normal. The higher you go the lower your airspeed becomes (air is thinner higher up) and results in a lower stall speed.

Have a look at the flight tutorials as there are some great ones to help out.
https://community.infiniteflight.com/c/tutorials/flight

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If you are stalling then you are too heavy or too slow for that altitude. In a heavy aircraft that has just reached its TOC you won’t be as high as other aircraft. Try climbing slower if this isn’t the case.

Yep take a look at this tutorial. Lower your initial cruise alt then climb after to your final cruise alt once you are lighter from burning off fuel.

I think thats the reason because i use a380

Even after i stop raising hieht it gets low

What’s your weight when this happens and your vertical speed (VS)?

On a long haul route you should probably start your cruise at 30000ft. Use SimBrief when flightplanning as this will calculate the altitudes for you.

What is sim brief could you please tell

Hello!

Simbrief is a flight-planning website. This topic explains it pretty well:


After you have checked out the first topic, this will be very helpful:

SimBrief.com is a flightplanning website. It gives you the route between your destinations, the fuel you’ll need and the altitudes as well as much more.

Thx very much all of you

Maybe you’re already doing some of these things, but let me just give out a few solutions:

  1. Is your speed being maintained by the autopilot? This might seem to simple of a solution, but sometimes people might genuinely forget to engage the auto-throttle, so be sure to check that you’ve done that, and that the thrust isn’t being manually maintained.

  2. Understand that your airspeed will naturally decrease as you get higher in altitude, if you are trying to maintain the same Mach number. So if you’ve set the autopilot to fly the plane at Mach 0.80, then don’t be alarmed if the airspeed keeps decreasing - the autopilot is simply trying to keep that ratio!

  3. Are you cruising too high? If you’re in a heavier aircraft, such as a fully weighed 747 or A380, then climbing straight to FL400 is not a good idea. Step climbing, so first climbing to FL300, and then to FL320, then FL340, then FL360, then FL380, and then finally to FL400 will allow time for the plane to lose some weight where is air is denser. SimBrief is an excellent online planning tool for these things, and it can also help a lot with other things to do with your flight as well, such as what speeds you should be cruising at for each aircraft, so be sure to check that out https://www.simbrief.com/home/ (on a side note, check that you’re cruising at the right speed for your aircraft type)! These articles should also help you out with navigating it Introduction to SimBrief and Copying Flight Aware and SimBrief FPL to Infinite Flight.

I hope that this might clarify things for you!