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Re: Flettner Strip Lengths/sizes: altitude oscillations

Subject: Re: Flettner Strip Lengths/sizes: altitude oscillations
From: Fred Fillinger <fillinger@ameritech.net>
Date: Fri, 17 Aug 2001 22:32:17
> A question for anyone on the subject of Flettner strips touched on below.
> I've noticed on the US factory demonstrator that the Flettner strips are not
> the full length of the trim tabs like the manual shows.  It looks like
> plastic report splines were used.  What are the latest opinions out there on
> full length strips and their heights?
> Dan Geldermann
> A139

I bet they're shorter cuz the plastic report binders come in one
length.  For cosmetics, there's no problem with full length.  The
Flettner strips serve only to increase effectiveness of the tabs (and
stick feel) in making small stick or trim adjustments.  Presuming they
do this by sticking up further into the boundary layer, which is
fairly thick back there, they need be no bigger than what the book
says.  Else I think all you get is more drag, as even the min. 5/16"
called for is many times the optimal trailing edge thickness for
minimum drag.

BTW, Anton Flettner invented the trim tab, but I can't find where his
tabs had strips.  He wouldn't have called them that, others later on
would have.  But 99.9% of trim tabs don't have them. ??? :) 

Regards,
Fred F., A063


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