X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 14 Oct 2013 13:16:25 -0400 Message-ID: X-Original-Return-Path: Received: from mail-oa0-f52.google.com ([209.85.219.52] verified) by logan.com (CommuniGate Pro SMTP 6.0.7) with ESMTPS id 6530408 for lml@lancaironline.net; Mon, 14 Oct 2013 08:56:50 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.219.52; envelope-from=toddlong1@gmail.com Received: by mail-oa0-f52.google.com with SMTP id n2so4492444oag.11 for ; Mon, 14 Oct 2013 05:56:15 -0700 (PDT) X-Received: by 10.60.83.47 with SMTP id n15mr370797oey.62.1381755374981; Mon, 14 Oct 2013 05:56:14 -0700 (PDT) X-Original-Return-Path: Received: from [10.251.187.226] (193.sub-174-225-197.myvzw.com. [174.225.197.193]) by mx.google.com with ESMTPSA id nw5sm41651480obc.9.1969.12.31.16.00.00 (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 14 Oct 2013 05:56:14 -0700 (PDT) Subject: Re: [LML] Re: Removing vacuum pump? (LIVP) References: From: Todd Long Content-Type: multipart/alternative; boundary=Apple-Mail-C9989986-3BC5-459D-8269-E87E45C43CBF X-Mailer: iPhone Mail (11A501) In-Reply-To: X-Original-Message-Id: <039DA6F4-8B13-4CA3-B9E5-4E61815AF85F@gmail.com> X-Original-Date: Mon, 14 Oct 2013 07:56:10 -0500 X-Original-To: Lancair Mailing List Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (1.0) --Apple-Mail-C9989986-3BC5-459D-8269-E87E45C43CBF Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable This dukes is electrically controlled. It does not work like what you find i= n a king air.=20 Typing and grammar errors courtesy of Siri and the iPhone. > On Oct 14, 2013, at 7:14, Paul Miller wrote: >=20 > If the pressure controller on the panel has rate of climb and cabin altitu= de settings (like a Garrett), it likely uses the vacuum line to modulate the= outflow valves (pull them open). That modulation is what provides the sign= al to allow the cabin to climb or descend. I don't know what controller is= in place but the vacuum is for cabin differential control. The squat switc= h is for ground use or emergency and simple opens the outflow to a maximum. = In a typical situation, the outflow closes with wheels up then the vacuum s= ignal starts to open the valves to provide the differential required to eith= er climb or hold the cabin as set by the controller. >=20 > If the vacuum is disconnected, I suspect you simply are running with a ful= ly closed outflow valve and the cabin pressure is an open loop with whatever= pressure is supplied from the firewall. Does that sound about right? >=20 > What I am missing is if there is no vacuum line then why install the contr= oller? How does it control anything? Those controllers can't be cheap. >=20 >=20 >> On 12 October 2013 17:00, jeffrey liegner wrote: >> The device might function better (although I can't prove that), but it i= s not necessary. I recall that it is to help the valve move initially (and h= as no value after that first movement) and effect a seal early=20 --Apple-Mail-C9989986-3BC5-459D-8269-E87E45C43CBF Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable

This dukes is electrically controlled.= It does not work like what you find in a king air.

Typing and g= rammar errors courtesy of Siri and the iPhone.

On Oct 14, 2013= , at 7:14, Paul Miller <pjdmiller@= gmail.com> wrote:

If the pressure controller on the panel has rate of climb and cabi= n altitude settings (like a Garrett), it likely uses the vacuum line to modu= late the outflow valves (pull them open). That modulation is what prov= ides the signal to allow the cabin to climb or descend. I don't know w= hat controller is in place but the vacuum is for cabin differential control.= The squat switch is for ground use or emergency and simple opens the o= utflow to a maximum. In a typical situation, the outflow closes with w= heels up then the vacuum signal starts to open the valves to provide the dif= ferential required to either climb or hold the cabin as set by the controlle= r.

If the vacuum is disconnected, I suspect you simply are runni= ng with a fully closed outflow valve and the cabin pressure is an open loop w= ith whatever pressure is supplied from the firewall. Does that sound a= bout right?

What I am missing is if there is no vacuum line then why= install the controller? How does it control anything? Those con= trollers can't be cheap.

On 12 October 2013 17:00, jeffrey liegner <liegner@ptd.net> wrot= e:
The device might function better (although I can't prove that), but i= t is not necessary. I recall that it is to help the valve move initial= ly (and has no value after that first movement) and effect a seal early = ;

= --Apple-Mail-C9989986-3BC5-459D-8269-E87E45C43CBF--