A33Zab,
Thanks, that answers my question.
Originally Posted by Owain Glyndwr
They would need dynamic pressure (Vc) and Mach to calculate the rudder deflection correction, so if either of these go NCD the estimated sideslip will also.
Maybe that is so, but I don't see it in the trace. Doesn't A33Zab say that in Alt2 it is replaced by Ny without correction?