CG position does affect the stalling characteristics - partly as BEagle said, and, at a more basic level, simply because the aircraft will stall with less back pressure and take longer to recover if the CG is significantly further aft than usual. This is particularly relevant to students who train in four-seaters with only two POB, as they will get little opportunity to observe MAUW, aft CG stalling characteristics.
Wing flap configuration does make a difference on many aircraft. The theory goes that, when flaps are deployed, most lift is developed inboard, closer to the lateral CG. In the event of a slip developing prior to the stall, there is less restoring moment and decreased lateral stability. If a stall occurs, it is more likely that one wing will have a greater angle of attack than the other, as the inboard, lift-developing, section of wing is more affected by slipstream asymmetries, and hence is more likely to develop asymmetric lift. The wing tips may contribute very little restoring force, as they generate only a small proportion of lift at VS0.
In addition to this, M1.1's comment about being out of balance is possibly the most common reason for a wing drop at any stall.
[Simple bit over, this bit for more advanced pilots.] The C152 seems to demonstrate the best (most sudden, greatest roll rate) wing drop stalls when clean. I speculate that this is because there is very little washout and the wing section, when clean, is such that the separation point moves rapidly forwards with a small change in AoA beyond the critical angle. When a stall occurs with a small asymmetry in lift, the resulting roll increases the angle of attack on the downgoing wing, but with much greater effect on the C152 than on aircraft with different wing sections.
As far as I'm aware, all modern aircraft certified in utility or normal categories must demonstrate aileron effectiveness at the clean (no flap) stall. Although this is certainly not the best way to recover(!), I think it is helpful to make the comment to students; they will observe in their training that the aileron actually does work, and some students may wonder 'why all the fuss' about not using aileron during the stall recovery.
With regard to a post on this forum by whatunion - I have no status on PPRuNe at all. But I do very much appreciate the chance to interact with pilots of the calibre of M1.1 & BEagle - and that's why I post. Whatunion- perhaps you could tone down your insults a little?
regards to all,
O8
Last edited by Oktas8; 30th May 2004 at 22:38.