X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Thu, 10 Oct 2013 08:39:05 -0400 Message-ID: X-Original-Return-Path: Received: from outbound-jr3.exchangedefender.com ([65.99.255.152] verified) by logan.com (CommuniGate Pro SMTP 6.0.7) with ESMTPS id 6509199 for lml@lancaironline.net; Thu, 10 Oct 2013 00:29:50 -0400 Received-SPF: pass receiver=logan.com; client-ip=65.99.255.152; envelope-from=cberland@systems3.net Received: from remote.systems3.net (wsip-98-172-79-178.ph.ph.cox.net [98.172.79.178]) by outbound-jr3.exchangedefender.com (8.13.8/8.13.8) with ESMTP id r9A4TEMJ026448 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=FAIL) for ; Thu, 10 Oct 2013 00:29:15 -0400 Received: from S3SBS11SERVER.Systems3.local ([fe80::5ce0:47a:d104:b76]) by S3SBS11SERVER.Systems3.local ([fe80::5ce0:47a:d104:b76%11]) with mapi id 14.01.0438.000; Wed, 9 Oct 2013 21:29:09 -0700 From: Craig Berland X-Original-To: Lancair Mailing List Subject: [LML] Re: Removing vacuum pump? Thread-Topic: [LML] Re: Removing vacuum pump? Thread-Index: AQHOxU2t8a9U6JzbrEycAvZjcbHifJntV+pO X-Original-Date: Thu, 10 Oct 2013 04:29:08 +0000 X-Original-Message-ID: <0A9BCB6D-7902-46BF-93CA-75A1B0335EFD@systems3.net> References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: Content-Type: multipart/alternative; boundary="_000_0A9BCB6D790246BF93CA75A1B0335EFDsystems3net_" MIME-Version: 1.0 X-ExchangeDefender-Info: Please contact the ISP for more information X-ExchangeDefender-VirusScan: Found to be clean X-ExchangeDefender-From: cberland@systems3.net X-ExchangeDefender-MagicKey: 1382588955.67261@qHRnzYJ+cc8s5X8LioS9mw X-Spam-Status: No --_000_0A9BCB6D790246BF93CA75A1B0335EFDsystems3net_ Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Bill, You are correct. That is what the Lancair build manual calls for. Some airc= raft have that wire removed. I have not tested this....but my understanding is the vacuum opens the dump= valve enough so no cabin pressure change is possible. I am very happy with= mine and have not tested other options. Craig Berland Sent from my iPad On Oct 9, 2013, at 5:14 PM, "William A. Hogarty" > wrote: I understood that the outflow valve was grounded whenever the gear switch w= as down. Is this wrong? Bill Hogarty On Wed, Oct 9, 2013 at 9:13 AM, Craig Berland > wrote: I have an all-electric airplane as well and chose to not have any vacuum su= pplied to the Dukes valve. The only difference is the rate in which pressu= rization starts building in the cabin on takeoff roll. Once airborne, vacu= um has no effect on the pressurization system. I choose to apply power a = little more slowly than some pilots. This prevents any pressurization disc= omfort and typically I don't need any right brake to hold centerline. Take= off distance is not an issue. If I can land there, I can easily takeoff th= ere. 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 a= re several options. In my opinion, keeping the engine driven pump is the l= east desirable. Craig Berland N7VG --_000_0A9BCB6D790246BF93CA75A1B0335EFDsystems3net_ Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Bill,

You are correct. That is what the Lancair build manual calls for. Some= aircraft have that wire removed.

I have not tested this....but my understanding is the vacuum opens the= dump valve enough so no cabin pressure change is possible. I am very happy= with mine and have not tested other options.

Craig Berland

Sent from my iPad

On Oct 9, 2013, at 5:14 PM, "William A. Hogarty" <billhogarty@gmail.com> wrote:

I understood that the outflow valve was grounded whenever the gear swi= tch was down.

Is this wrong?

Bill Hogarty

On Wed, Oct 9, 2013 at 9:13 AM, Craig Berland <cberland@sys= tems3.net> wrote:

I have an all-electric airplane as well and chose to not have any vacuum su= pplied to the Dukes valve. The only difference is the rate in which p= ressurization starts building in the cabin on takeoff roll. Once airb= orne, vacuum has no effect on the pressurization system. I choose to apply power a little more slowly than some pilo= ts. 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 c= ontrol a small electric vacuum pump based on the landing gear position. &nb= sp;So there are several options. In my opinion, keeping the engine dr= iven pump is the least desirable.

Craig Berland
N7VG

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