True airspeed gauge and pitot blockage

Hello to the avsim.net community! This is my first message in this forum.When a pitot is blocked with ice, the airspeed indicator shows 0 speed, this is a usual event. I was making a gauge for a Russian aircraft, that commonly rather use true airspeed indicators in km/h units. I used (A:Airspeed true, kilometer/hour), inserted failure tag, so the code looked like this:(A:Airspeed true, kilometer/hour) ... When the pitot blocked, and the autothrottle turned on the max trust, the gauge still indicated the true airspeed without a failure. What is the meaning of those "magic" lines? Actually I don't know yet if the real gauges rely on pitot rather than on a (doppler) radar. So I tried to make this effect just to let it be. So I had to make a special macro to check if airspeed is indicatable.0 (A:Airspeed true, kilometer/hour) (A:Airspeed indicated, knots) 0 == ?@iKph ...