Sorry Bernd, I'll have to disagree on some of your points.
Originally Posted by bsieker
"Deep Stall" or "Superstall" is a condition only encountered by T-Tail jets.
Deep stall is condition encountered by any aeroplane which elevators lose effectiveness when horizontal stabilizer gets into wake from stalled wing and there is no pronounced pitch-down in stall. Even F-104 and DC-6 can suffer from it if CoG is particularly unfavourable. T-tailed transport category aeroplanes are particularly vulnerable because of highly loaded wings and relatively inefficient elevator (relative to aerobatic aeroplanes, that is, it meets certification criteria and works well under normal circumstances) that gets behind the wing just as it's about to stall.
Originally Posted by bsieker
Propeller aircraft are not susceptible to deep stall, since the propwash will provide sufficient airflow over the elevators.
Sorry but propwash on twin turboprops does not affect the elevators, fortunately, I don't know if I could live through autopilotless days with yoke vibrating from propwash. One of the first things I found amusing when starting flying ATR was that there was no trim change with power change, but speed change did require quite a lot of trim, compared to small piston twins. Whether propwash would find its way to the elevators of ATR spinning flatly, I don't know and never had the intention of finding out. ATR was not keen on finding out either as the aeroplane was provided with stick pusher. IIRC shaker activated at 12.5° AoA normal condition and 8.5° icing conditions (shift was automatic, with turning the flight controls heat on) but pusher always fired at 15°.
In addition, non-swept wings have much more benign stall characteristics; generally they pitch down after the onset of stall, swept wings, unless specifically designed otherwise, will expose pitch-up tendencies when stalled.
If the swept wing's tip stalls first, center of pressure moves forward giving pitch-up as the wing stalls. Not good. Therefore to meet certification requirements, wing has to stall root first and considerable washout is required to achieve this. As for benign stall characteristics, turboprop's straight and thick wings do stall nicer than thin, swept ones but they still have more bite than the wings of Cessna 172.
B737 is not a T-Tail and as such not susceptible to Deep Stalls. It still has a stick pusher, as do all airliners except the side-stick-operated FBW airbus.
IIRC, our B732s didn't have pushers and B727 do or don't have pushers depending on their reg i.e. local CAA's standards of airworthiness. I stand to be corrected on this, though.