Hazelnuts
In the graph of CLmax vs mach number for the DC9 (no flaps, no flaps), I note that CLmax increases between Mach 0.8 and 0.9 . That seems somewhat odd and I see no reason for it. Can you explain it?
Maybe because it is labelled tail off from flight test ????
Seriously, it might be just the flight test value, which could be buffet limited rather than a genuine stall, and an estimated correction for tail load which might or might not be credible.
Source I think is the course notes for Stanford University AA241