[NSRCA-discussion] How I became an expert Snap Judge (TIC)

[James Oddino]

The way I see it, most of the folks think that the wing is stalled or  
it isn't.  This is not the case.  Stalled typically refers to the  
portion of the CL/alpha curve to the right, above the critical alpha.   
The CL does not go to zero when alpha exceeds the critical 15 or so  
degrees but drops with a relatively low slope.  That means it is still  
providing lift.  It can also be at different values on each panel.   
This is what Jerry was talking about when he referred to stalling the  
wing asymmetrically.  (See excerpt below).

I submit we can create a similar asymmetrical Lift on the left side of  
the curve, below the critical angle and produce a SNAP ROLL with the  
application of ailerons.  This is probably not a true autorotation  
that would occur with rudder and elevator only if we were on the  
"stalled" side of the curve, but the resulting airframe response looks  
the same.

I rest my case, Jim

I am not an aeronautical engineer.  Where is Jim Alberico when we need  
him?

On Oct 15, 2009, at 6:23 PM, Ron Van Putte wrote:

> I was busy when this came in and didn't sit down to read it until  
> tonight.  I'm an aeronautical engineer and EVERYTHING Jerry wrote  
> made sense to me and I'm a picky engineer.  I hope everyone was able  
> to wade their way through it and understood what Jerry wrote.  He  
> used some technical stuff that may have slowed some down, but it was  
> presented in such a way that most R/C aerobatic pilots should  
> understand the logic.
>
> Well done Jerry.
>
> Ron Van Putte
>
> On Oct 14, 2009, at 5:12 AM, Budd Engineering wrote:
>
>> So what are we doing to make the plane present what appears to be a  
>> snap roll when we can't actually be stalling the wing  
>> asymmetrically to induce autorotation like many claim?