X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 12 Mar 2008 09:53:02 -0400 Message-ID: X-Original-Return-Path: Received: from mta10.adelphia.net ([68.168.78.202] verified) by logan.com (CommuniGate Pro SMTP 5.2.0) with ESMTP id 2788223 for lml@lancaironline.net; Wed, 12 Mar 2008 08:23:17 -0400 Received-SPF: pass receiver=logan.com; client-ip=68.168.78.202; envelope-from=glcasey@adelphia.net Received: from [75.82.216.175] by mta10.adelphia.net (InterMail vM.6.01.05.02 201-2131-123-102-20050715) with ESMTP id <20080312122236.DVJS20654.mta10.adelphia.net@[75.82.216.175]> for ; Wed, 12 Mar 2008 08:22:36 -0400 Mime-Version: 1.0 (Apple Message framework v753) In-Reply-To: References: Content-Type: multipart/alternative; boundary=Apple-Mail-83--615912923 X-Original-Message-Id: From: Gary Casey Subject: Re: Spoilers for IVP X-Original-Date: Wed, 12 Mar 2008 05:22:33 -0700 X-Original-To: "Lancair Mailing List" X-Mailer: Apple Mail (2.753) --Apple-Mail-83--615912923 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed I don't have any direct experience with these, but I still have an opinion: Any spoiler system can exhibit asymmetric deployment, so the plane should be (easily) controllable regardless of the spoiler symmetry. A spoiler longer in span and less in height might be more of a challenge, but I would think not. If the spoiler is hinged at the front, hydraulically powered and reasonable friction free there is a good chance that the deployment will be equal, even at partial deployment - but not necessarily. How are the spoilers retracted? Springs? Double-acting cylinder? I wouldn't count on aerodynamic forces to return it completely flush with the wing. Is there a spoiler only on the top surface? If so, the roll moment will probably be significant in case of asymmetric deployment. And the comment before about the advisability of tapping into the gear hydraulic system is something to consider. Go to a manually-pumped hydraulic system with a dedicated reservoir? Gary Casey On Mar 12, 2008, at 3:00 AM, Lancair Mailing List wrote: > > From: "John Barrett" <2thman@cablespeed.com> > Date: March 11, 2008 7:32:28 AM PDT > To: lml@lancaironline.net > Subject: FW: Spoilers for IVP > > > It surprises me no one has offered any opinions on this question so > I'm > sending again hoping to get some useful input. > > Thanks for your thoughts. > > John Barrett > --Apple-Mail-83--615912923 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=ISO-8859-1 I don't have any direct experience with these, but I still have an = opinion: =A0Any spoiler system can exhibit asymmetric deployment, so the = plane should be (easily) controllable regardless of the spoiler = symmetry. =A0A spoiler longer in span and less in height might be more = of a challenge, but I would think not. =A0If the spoiler is hinged at = the front, hydraulically powered and reasonable friction free there is a = good chance that the deployment will be equal, even at partial = deployment - but not necessarily. =A0How are the spoilers retracted? = =A0Springs? =A0Double-acting cylinder? =A0I wouldn't count on = aerodynamic forces to return it completely flush with the wing. =A0Is = there a spoiler only on the top surface? =A0If so, the roll moment will = probably be significant in case of asymmetric deployment. =A0And the = comment before about the advisability of tapping into the gear hydraulic = system is something to consider. =A0Go to a manually-pumped hydraulic = system with a dedicated reservoir?

Gary Casey

On = Mar 12, 2008, at 3:00 AM, Lancair Mailing List wrote:

From: "John Barrett" <2thman@cablespeed.com>=
Date: March 11, 2008 7:32:28 AM = PDT
To: lml@lancaironline.net
Subject: FW: Spoilers for = IVP

It = surprises me no one has offered any opinions on this question so = I'm
sending again hoping to get some = useful input.

Thanks for your thoughts.

John = Barrett