X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 29 Nov 2011 12:22:40 -0500 Message-ID: X-Original-Return-Path: Received: from imr-mb02.mx.aol.com ([64.12.207.163] verified) by logan.com (CommuniGate Pro SMTP 5.4.2) with ESMTP id 5262826 for lml@lancaironline.net; Mon, 28 Nov 2011 21:46:02 -0500 Received-SPF: pass receiver=logan.com; client-ip=64.12.207.163; envelope-from=PTACKABURY@aol.com Received: from mtaomg-da05.r1000.mx.aol.com (mtaomg-da05.r1000.mx.aol.com [172.29.51.141]) by imr-mb02.mx.aol.com (8.14.1/8.14.1) with ESMTP id pAT2jM0D014965 for ; Mon, 28 Nov 2011 21:45:22 -0500 Received: from core-dqc003a.r1000.mail.aol.com (core-dqc003.r1000.mail.aol.com [172.29.161.137]) by mtaomg-da05.r1000.mx.aol.com (OMAG/Core Interface) with ESMTP id 32686E000092 for ; Mon, 28 Nov 2011 21:45:22 -0500 (EST) From: PTACKABURY@aol.com X-Original-Message-ID: <376d6.7c2cee61.3c05a141@aol.com> X-Original-Date: Mon, 28 Nov 2011 21:45:22 -0500 (EST) Subject: Re: [LML] Re: Legacy vibrations resolved X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_376d6.7c2cee61.3c05a141_boundary" X-Mailer: AOL 9.6 sub 5004 X-Originating-IP: [72.234.83.176] x-aol-global-disposition: G X-AOL-SCOLL-SCORE: 1:2:359613056:93952408 X-AOL-SCOLL-URL_COUNT: 1 x-aol-sid: 3039ac1d338d4ed447420916 --part1_376d6.7c2cee61.3c05a141_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 11/28/2011 11:51:30 A.M. Hawaiian Standard Time, charliekohler@yahoo.com writes: Your pictures apply to CONTROL surfaces also! Charlie K. See me on the web www.Lanc_air-IV.com_ (http://air-iv.com/) Sent from my iPad On Nov 28, 2011, at 10:52 AM, Chris Zavatson <_chris_zavatson@yahoo.com_ (mailto:chris_zavatson@yahoo.com) > wrote: There was another item observed during the trim tab examination that deserves mentioning. I have seen this on other Lancairs as well. The concept really applies to any hinged control surface. Wherever flow transitions from one flying surface to another, i.e. wing to aileron or flap, horizontal stab to elevator, or elevator to tab, care must be taken to ensure the trailing surface is in line with or slightly protrudes into the slip stream. (see sketch) Flow readily separates if the in-trail surface is not in proper alignment. Best case is one merely suffers a drag penalty. Worst case is the effectiveness of the surface is compromised. Many control surface designs will intentional project the leading edge into the slipstream during control surface deflection to assure flow remains attached. In the case of the the trim tab, the separated flow served as an excitation on the loose tab. This, in turn, got the elevator oscillating which was felt in the control stick. Chris Zavatson N91CZ 360 std _www.N91CZ.net_ (http://www.n91cz.net/) -- For archives and unsub _http://mail.lancaironline.net: 81/lists/lml/List.html_ (http://mail.lancaironline.net:81/lists/lml/List.html) --part1_376d6.7c2cee61.3c05a141_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
 
 
In a message dated 11/28/2011 11:51:30 A.M. Hawaiian Standard Time,=20 charliekohler@yahoo.com writes:
=
Your pictures apply to CONTROL surfaces also!

Charlie K.=20
See me on the web
        
www.Lancair-IV.com

Sent from my iPad


On Nov 28, 2011, at 10:52 AM, Chris Zavatson <chris_zavatson@yahoo.com>= =20 wrote:

There was another i= tem=20 observed during the trim tab examination that deserves mentioning. = ; I=20 have seen this on other Lancairs as=20 well.  The concept really applies to any hinged control surface.&n= bsp;=20
Wherever flow=20 transitions from one flying surface to another, i.e. wing to aileron or= =20 flap, horizontal stab to elevator, or elevator to tab, care must be tak= en to=20 ensure the trailing surface is in line with or slightly protr= udes=20 into the slip stream. (see sketch)  Flow readily separat= es if=20 the in-trail surface is not in proper alignment.  Best case is one= =20 merely suffers a drag penalty.  Worst case is the effectiveness of= the=20 surface is compromised.  Many control surface designs will intenti= onal=20 project the leading edge into the slipstream during control surfac= e=20 deflection to assure flow remains attached.  In the case of t= he=20 the trim tab, the separated flow served as an excitation on the lo= ose=20 tab.  This, in turn, got the elevator oscillating which was felt i= n the=20 control stick. 
 
Chris=20 Zavatson
N91CZ
360=20 std





=
<TabFlow.jpg>
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For archives and unsub http://ma= il.lancaironline.net:81/lists/lml/List.html
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