[NSRCA-discussion] Snap entry in FAI

[James Oddino]

In the missile business we defined a stalled wing as the point where  
the lift didn't increase with further increase of angle of attack.  It  
didn't mean the wing lost all lift, it just didn't increase.  Some  
airfoils hang on and some fall off very quickly.  I always thought we  
wanted the latter on models to assure good snaps and spins entries.   
As I recall wing aspect ratio plays a part also.

Jim O


On Jun 30, 2008, at 5:22 AM, Bob Richards wrote:

> When a wing stalls, it simply means the airflow detaches from the  
> top of the wing. The air is still flowing on the bottom of the wing,  
> the wing is still providing some lift, and the ailerons can still  
> deflect this flow. If this was not the case, a rolling harrier would  
> not be possible. (Shame on me for mentioning 3D flying on a  
> precision aerobatics newslist!! :-)   )
>
>
> Deflecting the aileron down will not necessarily cause the wing to  
> stall quicker, in fact as the wing starts to move up (roll rotation)  
> the angle of attack is actually decreased on the rising wing, and  
> increased on the falling wing. This is how one wing panel can be  
> stalled and not the other.
>
>
> Besides, if deflecting the trailing edge down causes a wing to stall  
> quicker, I don't think flaps would be a good idea on a landing  
> approach.
>
>
>
> Bob R
>
>
>
> --- On Mon, 6/30/08, Del <drykert2 at rochester.rr.com> wrote:
>
> ----- Original Message -----
> I would like someone to explain how, if the wing, or one panel, is  
> stalled how the ailerons are continuing to control the direction of  
> rotation. If there is a stalled wing, then it will be the one with  
> the "down" aileron as that wing has the higher incidence angle. This  
> stalled panel would cause a roll contrary to the aileron deflection.  
> This is actually what happens when you get an oeverweight airplane  
> too slow and add some surface deflections. It will snap contrary to  
> the aileron.
>
> _______________________________________________
> NSRCA-discussion mailing list
> NSRCA-discussion at lists.nsrca.org
> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
> _______________________________________________
> NSRCA-discussion mailing list
> NSRCA-discussion at lists.nsrca.org
> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.nsrca.org/pipermail/nsrca-discussion/attachments/20080630/0d9050fd/attachment.html>