X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sat, 12 Oct 2013 18:57:49 -0400 Message-ID: X-Original-Return-Path: Received: from mail-oa0-f51.google.com ([209.85.219.51] verified) by logan.com (CommuniGate Pro SMTP 6.0.7) with ESMTPS id 6511398 for lml@lancaironline.net; Fri, 11 Oct 2013 09:12:28 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.219.51; envelope-from=toddlong1@gmail.com Received: by mail-oa0-f51.google.com with SMTP id h16so2402101oag.10 for ; Fri, 11 Oct 2013 06:11:51 -0700 (PDT) X-Received: by 10.182.22.5 with SMTP id z5mr9950871obe.42.1381497111405; Fri, 11 Oct 2013 06:11:51 -0700 (PDT) X-Original-Return-Path: Received: from [10.229.246.134] (88.sub-174-230-194.myvzw.com. [174.230.194.88]) by mx.google.com with ESMTPSA id z5sm23668536obg.13.1969.12.31.16.00.00 (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Fri, 11 Oct 2013 06:11:50 -0700 (PDT) Subject: Re: [LML] Re: Removing vacuum pump? References: From: Todd Long Content-Type: multipart/alternative; boundary=Apple-Mail-3B224B1C-0B28-4446-A7CB-BAA231CAFCF5 X-Mailer: iPhone Mail (11A501) In-Reply-To: X-Original-Message-Id: X-Original-Date: Fri, 11 Oct 2013 08:11:46 -0500 X-Original-To: Lancair Mailing List Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (1.0) --Apple-Mail-3B224B1C-0B28-4446-A7CB-BAA231CAFCF5 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable The valve helps smooth out pressurization changes with power changes. It all= ows the outflow valves to do their job better. But yes it would provide a small margin of pressurization after the engine f= ailure. That would change the event from a rapid decompression to leak down.= If it was a rapid decompression it will fog or ice up your window at altitu= de. One more thing to deal with. I was just wondering if anybody knew I wasn= 't in the system. Because all the engineers of all the certified pressurized= aircraft have them. Typing and grammar errors courtesy of Siri and the iPhone. > On Oct 11, 2013, at 7:47, Colyn Case wrote: >=20 > What would be the advantage? seconds more pressurized time in case of e= ngine failure? >=20 > On Oct 11, 2013, at 7:52 AM, Todd Long wrote: >=20 > Does anyone know why there is no check valve on the pressurization? Cessna= P210 and Malibu both have them. >=20 > Typing and grammar errors courtesy of Siri and the iPhone. >=20 >> On Oct 10, 2013, at 14:49, "pete@leapfrogventures.com" wrote: >>=20 >> The Lancair wiring diagram shows an interconnect switch between the landi= ng gear and the pressurization system. IMHO, this is a complete waste of co= mplexity. Because there is no backflow valve on the pressure inlet from the= intercoolers, once you pull the power below 20 MAP the cabin will completel= y depressurize. >> =20 >> Pete >> =20 >> From: William A. Hogarty [mailto:billhogarty@gmail.com]=20 >> Sent: Wednesday, October 09, 2013 5:14 PM >> To: Lancair Mailing List >> Subject: Re: [LML] Removing vacuum pump? >> =20 >> I understood that the outflow valve was grounded whenever the gear switch= was down. >> =20 >> Is this wrong? >> =20 >> Bill Hogarty >> =20 >>=20 >> On Wed, Oct 9, 2013 at 9:13 AM, Craig Berland wro= te: >> I have an all-electric airplane as well and chose to not have any vacuum s= upplied to the Dukes valve. The only difference is the rate in which pressu= rization starts building in the cabin on takeoff roll. Once airborne, vacuu= m has no effect on the pressurization system. I choose to apply power a li= ttle more slowly than some pilots. This prevents any pressurization discomf= ort and typically I don't need any right brake to hold centerline. Takeoff d= istance 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 e= lectric vacuum pump based on the landing gear position. So there are severa= l options. In my opinion, keeping the engine driven pump is the least desir= able. >>=20 >> Craig Berland >> N7VG >>=20 >>=20 >> Hello Dico, >> You will need a vacuum port to the Dukes pressure valve for the pressuriz= ation to work correctly, I do not have any gyro instruments either but I nee= ded to install an electric vacuum pump near the Dukes valve >> Kamal T >> N1104T >>=20 >>=20 >>=20 >>=20 >> -- >> For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.ht= ml >=20 --Apple-Mail-3B224B1C-0B28-4446-A7CB-BAA231CAFCF5 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
The valve helps smooth out pressurizat= ion changes with power changes. It allows the outflow valves to do their job= better.
But yes it would provide a small margin of pressurization= after the engine failure. That would change the event from a rapid decompre= ssion to leak down. If it was a rapid decompression it will fog or ice up yo= ur window at altitude. One more thing to deal with. I was just wondering if a= nybody knew I wasn't in the system. Because all the engineers of all the cer= tified pressurized aircraft have them.

Typing and grammar errors cour= tesy of Siri and the iPhone.

On Oct 11, 2013, at 7:47, Colyn C= ase <colyncase@earthlink.net> wrote:

What would be the a= dvantage?    seconds more pressurized time in case of engine failu= re?

On Oct 11, 2013, at 7:52 AM, Todd Long wrote:
Does anyone know wh= y there is no check valve on the pressurization? Cessna P210 and Malibu both= have them.

Typing and grammar errors courtesy of Siri and the iPhone= .

The Lancair wiring diagram shows an interconnect switch between t= he landing gear and the pressurization system.  IMHO, this is a complet= e waste of complexity.  Because there is no backflow va= lve on the pressure inlet from the intercoolers, once you pull the power bel= ow 20 MAP the cabin will completely depressurize.

 

Pete

&n= bsp;

From: William A. Hogarty [mailto:billhogarty@gmail.com]
Sent: Wednesday, October 09, 2013 5:14 PM
To: Lancair Mailing List
Subject: Re: [LML] Removing vacuum pump= ?

 <= /font>

I understood that the outflow valv= e was grounded whenever the gear switch was down.

 

=

Is this wrong?

<= div>

 

Bill Hogarty

=

 <= /font>

On Wed, Oct 9, 2013 at 9:13 AM, Craig B= erland <cberla= nd@systems3.net> wrote:

I have an all-electric airplane as well and chose to not have any vacuu= m supplied to the Dukes valve.  The only difference is the rate in whic= h pressurization starts building in the cabin on takeoff roll.  Once ai= rborne, vacuum has no effect on the pressurization system.   I choose t= o apply power a little more slowly than some pilots.  This prevents any= pressurization discomfort and typically I don't need any right brake to hol= d centerline.  Takeoff distance is not an issue.  If I can land th= ere, 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 lan= ding 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 p= ressure valve for the pressurization to work correctly, I do not have any gy= ro instruments either but I needed to install an electric vacuum pump near t= he Dukes valve
Kamal T
N1104T




--
For archives an= d unsub http://mail.lancaironline.net:81/lists/lml/List.html=

 <= /font>


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