X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 2 [X] Return-Path: Sender: To: lml@lancaironline.net Date: Sun, 18 Mar 2007 10:14:20 -0400 Message-ID: X-Original-Return-Path: Received: from imo-m16.mx.aol.com ([64.12.138.206] verified) by logan.com (CommuniGate Pro SMTP 5.1.7) with ESMTP id 1927080 for lml@lancaironline.net; Sat, 17 Mar 2007 22:53:28 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.12.138.206; envelope-from=Sky2high@aol.com Received: from Sky2high@aol.com by imo-m16.mx.aol.com (mail_out_v38_r7.6.) id q.ce5.c23a47a (43930) for ; Sat, 17 Mar 2007 22:52:30 -0400 (EDT) From: Sky2high@aol.com X-Original-Message-ID: X-Original-Date: Sat, 17 Mar 2007 22:52:30 EDT Subject: Re: [LML] Aileron Flutter X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1174186350" X-Mailer: 9.0 Security Edition for Windows sub 5358 X-Spam-Flag: NO -------------------------------1174186350 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 3/17/2007 2:37:39 P.M. Central Daylight Time, randystuar t@hotmail.com writes: I'm flying around today and I looked out the cockpit and I noticed my right aileron fluttering. Looked at my left aileron and it's doing the same thing. I turn left and right, the ailerons are working fine but still fluttering. I got to my desination, bought some fuel and went flying some more. This time I didn't see much flutter, if any, at all. Anyone seen this or have any info about it? Randy, Rather than destructive flutter, it sounds like slop in the system and/or failure to balance the ailerons (like after painting). Before you check the balance, clamp one aileron to the wing tip. Go over to the other aileron and move it up and down (no more than 2 or 3 pounds of pressure). If you can move the unsecured aileron more than 1/2 inch in both directions, consider system slop from loose hinges and lash in the many rod ends that link the system. With the ailerons in a completely neutral position, there are little or no forces applied and the dead band may look like flutter simply because of system slop or balance problems. One goes up a bit and the airflow forces it back down and that starts the other side up, etc. As was mentioned by Bob, the airframe/wing vibration may also induce the appearance of flutter. Another consideration is a sloppy trim tab (loose hinge?). I have used oversize hinge pins (big reduction in slop) and have rigged both ailerons slightly up to carry a wee bit of air load and thus remain in place. My dead band was significant because I use a spring-bias trim system and if the wing loads are balanced, there is little or no force applied by the springs to such a neutral system. Let us know what you find out. Scott Krueger AKA Grayhawk Lancair N92EX IO320 SB 89/96 Aurora, IL (KARR) Darwinian culling phrase: Watch This! ************************************** AOL now offers free email to everyone. Find out more about what's free from AOL at http://www.aol.com. -------------------------------1174186350 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable

In a message dated 3/17/2007 2:37:39 P.M. Central Daylight Time,=20 randystuart@hotmail.com writes:

<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3D"Lucida Sans Unicode" color= =3D#000000=20 size=3D2>

I'm flying around today and I look= ed out=20 the cockpit and I noticed my right aileron fluttering. Looked at my l= eft=20 aileron and it's doing the same thing. I turn left and right, the ailerons= are=20 working fine but still fluttering. I got to my desination, bought some fue= l=20 and went flying some more. This time I didn't see much flutter, if any, at= =20 all.

Anyone seen this or have any info=20= about=20 it?

Randy,

Rather than destructive flutter, it sounds like slop in the system and/= or=20 failure to balance the ailerons (like after painting).

Before you check the balance, clamp one aileron to the wing tip. =20= Go=20 over to the other aileron and move it up and down (no more than 2 or 3=20 pounds of pressure). If you can move the unsecured aileron more t= han=20 1/2 inch in both directions, consider system slop from loose hinges and lash= in=20 the many rod ends that link the system. With the ailerons in a complet= ely=20 neutral position, there are little or no forces applied and the dead band ma= y=20 look like flutter simply because of system slop or balance problems. One goe= s up=20 a bit and the airflow forces it back down and that starts the other side up,= =20 etc. As was mentioned by Bob, the airframe/wing vibration may also ind= uce=20 the appearance of flutter. Another consideration is a sloppy trim tab=20 (loose hinge?).

I have used oversize hinge pins (big reduction in slop) and have= =20 rigged both ailerons slightly up to carry a wee bit of air load and thu= s=20 remain in place. My dead band was significant because I use=20 a spring-bias trim system and if the wing loads are balanced, there=20 is little or no force applied by the springs to such a neutral=20 system.

Let us know what you find out.=20

Scott Krueger=20 AKA Grayhawk
Lancair N92EX IO320 SB 89/96
Aurora, IL=20 (KARR)

Darwinian culling phrase: Watch=20 This!

AOL now= offers free email to everyone. Find out more about what's free from AOL at= AOL.com.

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