Deep stall doesn't require extreme angles of incidence. It just requires sufficient incidence that the nose down pitching moments available to the pilot are insufficient for recovery.
I would be surprised if AF447 didn't achieve incidence angles far beyond those at which some T tailed types would be considered deep stalled, but it demonstrated roll oscillations showing that there were cyclic variations in lift across the wing.
During the early days of deep stall research it was found, for at least one transport aircraft type, that apparently benign sink in a level attitude could result in deep stall alpha with the pilot unaware of what was occurring.
Of course, many cases of deep stall do require extreme alpha to "lock in".
With regard to aerodynamic controls on a stalled wing, they are often shown to be effective, albiet with, probably, hugely reduced response.
I have no idea how "deeply" stalled the Hunter wing was during spinning, but on a daily basis demonstrations were made of the power of the ailerons to either recover from a spin, despite full pro-spin controls being held with the rudder and elevators, or prevent spin recovery despite full anti spin controls being held with the rudder and elevator.
This was a demonstration of the rolling moments the ailerons could produce which cross coupled to produce significant pro or anti spin yawing moments.
Last edited by zzuf; 11th Aug 2018 at 02:57.