Thanks for the detailed expeanation Italia, but I'm just not getting the part about increased AoA incresing stall speed. It looks like we agree on all the rest.
Though I have done high speed pull ups in a C150 Aerobat (just 'cause I could) and made it "stall" at an unusually high speed, I don't really think that counts, or qualifies as a true explanation of the relationship between AoA and stall speed. Aside from possibly ripping it off, any airfoil can be taken to an extreme AoA at any speed, and "stall", but doing that does not conform to the accepted flight test technique for determining stall speeds, so I don't accept it as relevent.
I maintain that were AoA a factor in stall speeds, flight manual data and airspeed indicator markings, and flight training would be very much more complicated than they are.
When stalling planes, which I do regularly, I always consider contaminated airfoils, high lift devices, G loading, and weight. AoA is just something which is a biproduct of the event.
Though I see the formula you present, I admit to not quite seeing how it applies in real world flying.
If AoA were a factor in a change in stall speed, how would an AoA indicator be of any use for aircraft attitude control to prevent unintended stalls? There you are refering to the AoA indicator as you carefully fly the aircraft in the approach to stall regime, and the stall speed is changing because of the increasing AoA, and suddenly moves in to meet you before you reach the critical AoA? I think not.
In my earlier days, my job was to fly newly STOL kitted Cessnas, for the purpose of confirming the correct set up of the stall warning vane (it must be repositioned, when the airfoil cuff is installed). That vane operates based simply upon AoA and stagnation point on the leading edge. If varying or increasing AoA changed the unacellerated stall speed, my task would have been impossible....
During recent flight testing in a Piper Cheyenne II, which required my repeated approach to the stall, I was using the AoA to get close, without getting too far into it. With some practice, I found flying well into the red of the AoA no problem. Indeed, the aircraft had a much more forgiving stall than I expected (based upon the urban myths of that type). That flight test was cut short with a landing gear problem (when the left main seemed to get stuck up during configuration change for test). After half an hour of no luck, I used the descent to get a flyby to do a few very steep turns to build up some G and try to pull it down. The Cheyenne does not seem to care for that kind of flying. It did not bite me, but it sure nibbled! I stopped doing that!
Could you offer some more explicit real world examples of civil aircraft for which the AoA is a stated factor in stall speed determination, beyond the agreed effect of G on stall speed? How is this documented in the flight manual and pilot training material?
I'm trying to see what you're saying, but I'm not there yet....