After almost 3 years in the A321 of FSX, it happened 3 times to me today:Suddenly during climb or descent (both around 5000ft), the speed indicators (both digital and analog) stop functioning and display 0 KIAS. Immediately, the Autothottle tries to accelerate the plane with full throttle, shortly after the plane crashes due to stress. I can disconnect the Autothrottle... but 2 times I tried to land the plane without any speed indication. It did not work out.I haven't set any failures in FSX, and haven't made any changes to any .cfg's prior to the problem appearing. Had 200+ hrs. IFR in that plane without faults and my system is very well tuned.Any help is appreciated!FSX SP2, GEX USA, REX 2.0, UT2, Scenery Tech Landclass

Turn your Pitot heat on its freezing up.

Are you serious? Why would that happen in August?

Hi,Because it can be cold above the ground, especially in the area of thunderstorms.Thanks,

I will try that now! I didn't even know the pilot heat was simulated ob the default A321...

I believe pitot heat is simulated on all default aircraft, and probably all add-ons too. (If the real plane has pitot heat.) As a rule of thumb, pitot icing is likely to occur when the outside air temperature is at or below 4 degrees Celcius and you are traveling through high humidity (clouds, rain, etc.) It doesn't matter what time of year it is, only what the temperature at altitude is. In FS the airspeed indicator will drop to 0 when the pitot ices up.

Thanks for the quick help, no more casualties. KCLT-KTPA easy.