X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from elasmtp-mealy.atl.sa.earthlink.net ([209.86.89.69] verified) by logan.com (CommuniGate Pro SMTP 6.0.7) with ESMTP id 6508673 for lml@lancaironline.net; Wed, 09 Oct 2013 14:13:45 -0400 Received-SPF: none receiver=logan.com; client-ip=209.86.89.69; envelope-from=colyncase@earthlink.net DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=dk20050327; d=earthlink.net; b=L9miNXb/XD7aYHQt62NUXFJKfBTeWtLynVkKOFKqYYYmBuUp0wOyUel1dG+QPaAX; h=Received:Content-Type:Mime-Version:Subject:From:In-Reply-To:Date:Content-Transfer-Encoding:Message-Id:References:To:X-Mailer:X-ELNK-Trace:X-Originating-IP; Received: from [71.161.205.110] (helo=[192.168.1.24]) by elasmtp-mealy.atl.sa.earthlink.net with esmtpa (Exim 4.67) (envelope-from ) id 1VTyFx-0006ma-06 for lml@lancaironline.net; Wed, 09 Oct 2013 14:13:09 -0400 Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Apple Message framework v1085) Subject: Re: [LML] Removing vacuum pump? From: Colyn Case In-Reply-To: Date: Wed, 9 Oct 2013 13:13:08 -0500 Content-Transfer-Encoding: quoted-printable Message-Id: <7AFF703A-AF9E-4709-86E8-549E156F36F5@earthlink.net> References: To: "Lancair Mailing List" X-Mailer: Apple Mail (2.1085) X-ELNK-Trace: 63d5d3452847f8b1d6dd28457998182d7e972de0d01da94008cea708aa3cdb633b7a539e98a65c2c350badd9bab72f9c350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 71.161.205.110 maybe Pete (leapfrog) can chime in here but I don't really understand = why Dukes put that in there. You could have the dump switch on during = takeoff, and there's another way to wire it that holds the outflow valve = full open. On Oct 9, 2013, at 11:13 AM, Craig Berland wrote: I have an all-electric airplane as well and chose to not have any vacuum = supplied to the Dukes valve. The only difference is the rate in which = pressurization starts building in the cabin on takeoff roll. Once = airborne, vacuum has no effect on the pressurization system. I choose = to apply power a little more slowly than some pilots. This prevents any = pressurization discomfort and typically I don't need any right brake to = hold centerline. Takeoff distance is not an issue. If I can land = there, I can easily takeoff there. I know one pilot who has developed = an electronic circuit to control a small electric vacuum pump based on = the landing gear position. So there are several options. In my = opinion, keeping the engine driven pump is the least desirable. Craig Berland N7VG Hello Dico, You will need a vacuum port to the Dukes pressure valve for the = pressurization to work correctly, I do not have any gyro instruments = either but I needed to install an electric vacuum pump near the Dukes = valve Kamal T N1104T -- For archives and unsub = http://mail.lancaironline.net:81/lists/lml/List.html