[NSRCA-discussion] Annhedral Stab

Sun Apr 20 11:42:49 AKDT 2008

Jim,

?

Most would say that anhedral stabs are hype......

?

I prefer to call them a?viable option for pattern models and here're my thoughts on the subject. First off, fundamentally, they don't change how the wing is stabilized in pitch compared to a flat stab...same physics apply. Anhedral area however is the resultant of?two component areas, horizontal which dominates and a vertical which adds to the already eixsting vertical stabilizer area. It may be thought as area added to the ventral side of the fuse without adding a subfin. This often helps settle some unwanted thrust vector forces namely the much cussed and discussed dredded pitch to belly with top rudder. Does it always work as prescribed? Does anything in our sport ever always work as prescribed?

?

Rolling circles may be helped with anhedral in the stab. When the anhedral angle is "just right", there is no region during?rotation (X degrees from horizontal) that completely blanks out the stab as can happen with flat stabs. Does is do wonders? I don't think so but it certainly does not hurt.

?

My new design will have anhedral in its stab (7-8 degrees)

?

Cheers,

?

MattK

-----Original Message-----

From: J N Hiller &lt;jnhiller at earthlink.net&gt;

To: NSRCA Mailing List &lt;nsrca-discussion at lists.nsrca.org&gt;

Sent: Sun, 20 Apr 2008 2:01 pm

Subject: [NSRCA-discussion] Annhedral Stab

Can I open a discussion on why some designs have an annhedral stab?  Was it to lower the effective flying height of the stab to reduce the wing  to stab vertical offset and knife edge belly pitch, or is there some other  reason?  Jim Hiller    _______________________________________________  NSRCA-discussion mailing list  NSRCA-discussion at lists.nsrca.org  http://lists.nsrca.org/mailman/listinfo/nsrca-discussion  

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.nsrca.org/pipermail/nsrca-discussion/attachments/20080420/9e5b49e3/attachment-0001.html 