Hi,Anyone know what causes this....If you take to long in climbing or descending through an overcast cloud layer, the Airspeed drops to ZERO!!?? ... especially annoying if you have the planes autothrottle active, the engine(s) suddenly rev to max, as the Autopilot thinks the plane is at zero speed... Is this a bug or a 'feature' ?? If it is a bug, is there a work around?TaLaz

I think this is one of the most frequent questions on flight sim forums around the world and it is very much a feature. ;-)It simulates what happens if you don't put on your pitot heaters. Then the pitot tube/s will get iced and stop working. Weather the speed will drop or increase is another issue...The above is if I presume right though. And I've been known to be wrong occasionally. But try to put on your heaters and try again!Cheers

AHHHHHH .. could explain it :-)However the panel that I have, with my most frequently used plane doesn't have a pitot heat switch.... Out of sight out of mind?I'll find a suitable switch & add the gauge, then see if it fixes?But to throw a spanner in the works, I've seen this happen when even climbing through the first overcast layer (base 500agl), on a mild day where the temp seems to still be well ABOVE zero in the cloud.Any thoughts??Laz

Shift H to turn pitot heat on/off.

A combination of Thermodynamics and Hydrodynamics.-hoo