Originally Posted by PJ2
Yes, you're correct in stating that I still find it difficult to believe that a clean wing (of the type under discussion -transport category, swept, super-critical airfoil) would stall as early as 6.5deg but as is also stated we don't yet have information on high-altitude stall AoAs. I look forward to continuing this.
The ACARS can provide the information (and a huge amount of other flight data) and it is easily accessible in-flight; I recall typical AoAs were 2.3deg approx. in cruise.
I don’t think either that such a wing would stall at 6.5 degrees of AoA, but I would rather think that a level flight at such AoA/attitude is unsustainable due to the lack of available thrust versus the tremendous increase in drag in a low air density environment.
During a Airshow, any airliner can demonstrate its capability to maintain a high AoA at low level thanks to its engines. The same demonstration at high level would be impossible. Just not enough thrust to maintain level flight above 5 degrees of attitude. Soon the altitude cannot be maintained, the attitude would be still anywhere between 5 and 7 degrees but as the aircraft is descending, the AoA could increase to the usual 15 to 20 degrees where stall usually happens … Just a thought.