REFLECTOR: Sparrow strainer - I'm confused...

[John Dibble]

Scott,

Great explanation.

John

On 9/14/2012 12:37 PM, Scott Derrick wrote:
>
>>
>>   If the Sparrow Strainer were inverted to provide nose down force as 
>> airspeed increases - this contributes to negative stability.  Which 
>> is to say, as the aircraft speeds up, the nose will want to pitch 
>> down ... which helps the aircraft speed up, which helps the nose 
>> pitch down further ... which helps the aircraft speed up - you get 
>> the idea.  Imagine this situation if disoriented in IMC.
>
> Anybody who's actually flown A Velocity with the sparrow strainer 
> installed both upside down, not installed and downside down, knows 
> that the above statement is completely and utterly false.  The plane 
> will in no way act in the above manner.   What is described above is 
> negative pitch stability, which the strainer is way way way to small 
> to induce. In fact it's too small to induce neutral stability when 
> installed upside down.
>
> Speaking from experience, upside or downside down installation changes 
> the pitch stability in a slight way, in fact its hard to tell the 
> difference in pitch stability, but it does make a slight positive  
> change in pitch trim in cruise.
>
> Scott
>
>
>
> _______________________________________________
> To change your email address, visit 
> http://www.tvbf.org/mailman/listinfo/reflector
>
> Visit the gallery!  www.tvbf.org/gallery
> user:pw = tvbf:jamaicangoose
> Check new archives: www.tvbf.org/pipermail
> Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
>