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

[Ron Van Putte]

Yes, I agree with the elimination of the autorotation/stall  
requirement and describe the desired flight path, not how to achieve it.

Ron VP

On Oct 16, 2009, at 9:41 AM, James Oddino wrote:

> Ron, I agree completely with you and Jerry.  My point is we can get  
> a similar airframe response at similar asymmetrical lift on the  
> left side by using ailerons along with rudder and elevator.   
> Autorotation refers to rolling induced by an unstable CL/alpha that  
> occurs only on the right side.  There, as alpha increases lift  
> decreases so the wing descends resulting in alpha increasing and so  
> on.  On the rising wing, alpha is decreasing so lift is increasing  
> so the wing keeps rising.  The result is a spontaneous, continuous   
> roll.
>
> This is untrue on the left side but we can and do induce rotation  
> with ailerons.  If we want to fix the rules we should probably get  
> rid of the autorotation/stall requirement and describe the desired  
> flight path, not how to achieve it.  Agree?
>
> Make sense?
>
> Jim
>
>
> On Oct 16, 2009, at 6:58 AM, Ron Van Putte wrote:
>
>> Jerry's point is that the airplane can't get to the portion of the  
>> CL/alpha curve to the right, above the critical alpha.  Too many  
>> Gs on the airplane at normal flying speed.
>>
>> Ron VP
>>
>> On Oct 16, 2009, at 12:36 AM, James Oddino wrote:
>>
>>> 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?
>>>
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>>
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