Hi rudderrudderrat,
Thanks for the link to an interesting paper. For the purpose of our discussion I think a few points are worth mentioning:
-- The presentation is dated 29 October 2013
-- It presents the views of Boeing and Airbus FTP's and FTE's, not necessarily that of the airworthiness authorities
-- The first bullet is "Stall Definition and Requirements", but the paper does not contain a discussion of that subject
-- The paper does not distinguish the tests conducted to determine the stall speeds from those to verify the stall characteristics or to identify aerodynamic characteristics such as the CLalpha curve
The A320 Special Conditions are dated 1988 and state clearly that Vs1g must be determined in normal law with alpha-floor disengaged. Consequently, Vs1g for the A320 is the speed obtained when the airplane is decelerated at 1 kt/s, the sidestick reaches the aft stop and is held there a few seconds. The published stall speeds and the cl-alpha observed in the accident (t-6 122 kt alpha=13.5) suggest that Vs1g corresponds to alpha-max of 17.5 degrees.