When we speak about the level flight of certain AC, I do not understand where is the problem with airspeed measurement in case of emergency situation (Fail of any airspeed measurement system). We know AC type, its flight physical model, weight, altitude, air density, all performance information, stall speed etc.. So why can we just monitor pitch in level flight and calculate actual airspeed?
dzumandzi: It seems you just discovered the "wheel"...
How about going back and read the thread? You might learn something.