X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from elasmtp-scoter.atl.sa.earthlink.net ([209.86.89.67] verified) by logan.com (CommuniGate Pro SMTP 6.0.7) with ESMTP id 6513216 for lml@lancaironline.net; Sat, 12 Oct 2013 21:07:36 -0400 Received-SPF: none receiver=logan.com; client-ip=209.86.89.67; envelope-from=colyncase@earthlink.net DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=dk20050327; d=earthlink.net; b=XgQOps0vkTzZ+8jrs4dzgFhpxeM9inZ46qIjWmdUtzysOh03CwPjociUVsRUC6ei; h=Received:From:Mime-Version:Content-Type:Subject:Date:In-Reply-To:To:References:Message-Id:X-Mailer:X-ELNK-Trace:X-Originating-IP; Received: from [71.181.17.143] (helo=[192.168.1.24]) by elasmtp-scoter.atl.sa.earthlink.net with esmtpa (Exim 4.67) (envelope-from ) id 1VVA98-0005En-CU for lml@lancaironline.net; Sat, 12 Oct 2013 21:07:03 -0400 From: Colyn Case Mime-Version: 1.0 (Apple Message framework v1085) Content-Type: multipart/alternative; boundary=Apple-Mail-183--407704893 Subject: Re: [LML] Re: Removing vacuum pump? Date: Sat, 12 Oct 2013 21:07:00 -0400 In-Reply-To: To: "Lancair Mailing List" References: Message-Id: <06537466-7AB0-4519-B1DB-EE736A8790E7@earthlink.net> X-Mailer: Apple Mail (2.1085) X-ELNK-Trace: 63d5d3452847f8b1d6dd28457998182d7e972de0d01da940ff5153b4242a3eedaf8943d8d578a675350badd9bab72f9c350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 71.181.17.143 --Apple-Mail-183--407704893 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii I don't know why we don't have them. I suspect that you have to = consider the dynamics of the particular outflow valve you have when = selecting an input check valve though. e.g. if you chop the power, the = outflow valve would have to close down very quickly for the input check = valve to have any net effect. =20 On Oct 12, 2013, at 6:57 PM, Todd Long wrote: The valve helps smooth out pressurization 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 decompression = to leak down. If it was a rapid decompression it will fog or ice up your = window at altitude. 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: > What would be the advantage? seconds more pressurized time in case = of engine 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 = landing gear and the pressurization system. IMHO, this is a complete = waste of complexity. Because there is no backflow valve on the pressure = inlet from the intercoolers, once you pull the power below 20 MAP the = cabin will completely 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 = 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. >>=20 >> Craig Berland >> N7VG >>=20 >>=20 >> 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 >>=20 >>=20 >>=20 >>=20 >> -- >> For archives and unsub = http://mail.lancaironline.net:81/lists/lml/List.html >> =20 >=20 --Apple-Mail-183--407704893 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=us-ascii I = don't know why we don't have them.    I suspect that you have = to consider the dynamics of the particular outflow valve you have when = selecting an input check valve though.   e.g. if you chop the = power, the outflow valve would have to close down very quickly for the = input check valve to have any net effect. =   

On Oct 12, 2013, at 6:57 PM, Todd Long = wrote:

The valve helps smooth out pressurization 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 decompression to leak down. If it was a rapid decompression = it will fog or ice up your window at altitude. 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 <colyncase@earthlink.net> = wrote:

What would be the = advantage?    seconds more pressurized time in case of engine = failure?

On Oct 11, 2013, at 7:52 AM, Todd Long = wrote:

Does anyone know why 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.

On Oct 10, = 2013, at 14:49, "pete@leapfrogventures.com" = <pete@leapfrogventures.com>= ; wrote:

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

 

Pete

 

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?

 

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

 

<= p class=3D"MsoNormal">Is this = wrong?

 

<= p class=3D"MsoNormal">Bill = Hogarty

 

On Wed, Oct 9, 2013 at 9:13 AM, Craig Berland = <cberland@systems3.net> = 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




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

 

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