Is it possible that the aircraft has an underlying stall speed variation with Mach number. Either through SPS functionality with Mach number or direct aerodynamic effect of Mach.
Then it's not just a case of applying the square root of load factor - you actually may have a (slightly) lower stall AoA at higher Mach, and hence a slightly different stall speed on which you have to base the *sqrt(nz) part of the equation.
There may be little or no effect at lower bank angles because the Mach is sufficiently low that there is no variation, but higher bank angles (and hence speeds) do introduce a Mach effect.
edit: on inspection, the flap 40 data are closer to agreeing with the classical relationship (to the accuracy one can read the graph) certainly to 50 degrees of bank at least; the two lines can be seen to be different in shape, too
Last edited by Mad (Flt) Scientist; 15th Jun 2004 at 16:02.