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

[James Oddino]

I believe there are at least three of us that understand what stall  
and autorotation mean.

Jim


On Oct 16, 2009, at 8:11 AM, Ron Van Putte wrote:

> 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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