Originally Posted by wiggy
Lots of use of the term "deep stall" here recently
It depends how you define "deep stall". For some it just means an AoA substantially greater than that at which the stall first manifests itself. The T-tail problem is the airplane being "locked-in" in that condition.
Originally Posted by ZeeDoktor
Could a transport category aircraft be certified if a deep stall condition can be produced simply by stalling
As far as I am aware, no one on this thread really knows how the airplane was certificated in this respect. Some contributors, for example PBL, on the basis of a literal interpretation of the relevant regulations, have suggested that an investigation of its stalling characteristics beyond "alpha max" was not required, by virtue of the AoA protections incorporated in its flight control system in "normal law".
That said I should emphasize that without further evidence, all talk about stall, deep stall, superstall, flat spin, etc. in relation to AF447 is just speculation and, IMHO, not the most likely scenario of what happened.
regards,
HN39