Return-Path: Sender: "Marvin Kaye" To: lml@lancaironline.net Date: Tue, 28 Sep 2004 18:08:31 -0400 Message-ID: X-Original-Return-Path: Received: from imo-m14.mx.aol.com ([64.12.138.204] verified) by logan.com (CommuniGate Pro SMTP 4.2.3) with ESMTP id 435807 for lml@lancaironline.net; Tue, 28 Sep 2004 17:41:55 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.12.138.204; envelope-from=MikeEasley@aol.com Received: from MikeEasley@aol.com by imo-m14.mx.aol.com (mail_out_v37_r3.7.) id q.1dc.2c1e6e66 (4328) for ; Tue, 28 Sep 2004 17:41:24 -0400 (EDT) From: MikeEasley@aol.com X-Original-Message-ID: <1dc.2c1e6e66.2e8b3483@aol.com> X-Original-Date: Tue, 28 Sep 2004 17:41:23 EDT Subject: Re: [LML] wing incidence indifference X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1096407683" X-Mailer: 9.0 for Windows sub 5113 -------------------------------1096407683 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Roberto, I totally agree with your last paragraph. "I also believe that using eccentric bushes to change wing incidence is not just poor practice but quite potentially dangerous. Perhaps Lancair Company might give the details of who in the Company has analysed this procedure, their qualifications and the analysis results including but not limited to the load carrying capability of the twisted spar at it's maximum load, the stall response of the asymmetric wing and stall progression from root to tip as is the design intent, the stall response under gust loads upto the structural limit of the aeroplane (the top of the green arc of the ASI) and beyond, the stall response with flaps partially and fully extended, the consequent differences in flap rigging and aileron rigging etc." Some of the things that come to mind... If you "tweak" the wings to get it to fly straight, you have only solved the "flying straight" problem. But at other speeds, with the flaps deflected, even different angles of attack, the wing may respond differently. My biggest concern is how the plane would respond at slow speeds, near the stall. When the dust settles on the incidence correction thing, I'll likely demand that Lancair machine me some custom banana brackets with holes offset by the exact amount of my eccentrics. Mike -------------------------------1096407683 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable

Roberto,

I totally agree with your last paragraph.

"I also believe that using eccentric bushes to change wing incidence is= not just poor practice but quite potentially dangerous. Perhaps Lancair Com= pany might give the details of who in the Company has analysed this procedur= e, their qualifications and the analysis results including but not limited t= o the load carrying capability of the twisted spar at it's maximum load, the= stall response of the asymmetric wing and stall progression from root to ti= p as is the design intent, the stall response under gust loads upto the stru= ctural limit of the aeroplane (the top of the green arc of the ASI) and beyo= nd, the stall response with flaps partially and fully extended, the con= sequent differences in flap rigging and aileron rigging etc."

Some of the things that come to mind...

If you "tweak" the wings to get it to fly straight, you have only solve= d the "flying straight" problem. But at other speeds, with the flaps d= eflected, even different angles of attack, the wing may respond differently.= My biggest concern is how the plane would respond at slow speeds, nea= r the stall.

When the dust settles on the incidence correction thing, I'll likely de= mand that Lancair machine me some custom banana brackets with holes offset b= y the exact amount of my eccentrics.

Mike

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