X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 29 Jan 2010 10:31:50 -0500 Message-ID: X-Original-Return-Path: Received: from elasmtp-scoter.atl.sa.earthlink.net ([209.86.89.67] verified) by logan.com (CommuniGate Pro SMTP 5.3.2) with ESMTP id 4102568 for lml@lancaironline.net; Thu, 28 Jan 2010 15:49:11 -0500 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=WmSx1UG6eCSNy/EjKFmapiCQudHg3YLevLC/fTRHBHsU2zsBJdCJYm+YcAe2Ilo0; h=Received:Message-ID:From:To:References:Subject:Date:MIME-Version:Content-Type:X-Priority:X-MSMail-Priority:X-Mailer:X-MimeOLE:X-ELNK-Trace:X-Originating-IP; Received: from [216.57.118.190] (helo=ccaselt3) by elasmtp-scoter.atl.sa.earthlink.net with esmtpa (Exim 4.67) (envelope-from ) id 1NabI4-00069C-1n for lml@lancaironline.net; Thu, 28 Jan 2010 15:48:36 -0500 X-Original-Message-ID: From: "Colyn Case at earthlink" X-Original-To: References: Subject: Re: [LML] Re: Airspeed sensing switch: Pressurization X-Original-Date: Thu, 28 Jan 2010 15:48:35 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0040_01CAA031.59E238C0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5843 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 X-ELNK-Trace: 63d5d3452847f8b1d6dd28457998182d7e972de0d01da940c06ea03d36d44d6ea089b104c1449d5c350badd9bab72f9c350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 216.57.118.190 This is a multi-part message in MIME format. ------=_NextPart_000_0040_01CAA031.59E238C0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Re: [LML] Re: Airspeed sensing switch: PressurizationPaul pointed out = the obvious: a door with even 1 psi behind it is dangerous. (1 psi = times 600 or so? I don't have the measurements) So I do buy the argument that at low throttle settings, and under normal = circumstances, you aren't going to have much residual pressure in the = cabin. But there are lots of possible failure modes here: a) pressure = controller malfunction b) pressure controller set way below landing = altitude c) exhaust valve is not operating correctly - not enough cabin = exchange rate. These may argue for the pressure switch The suggestion I like the best is "check cabin pressure before opening = the door". ------=_NextPart_000_0040_01CAA031.59E238C0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Re: [LML] Re: Airspeed sensing switch: = Pressurization
Paul pointed out the = obvious:   a door=20 with even 1 psi behind it is dangerous.  (1 psi times 600 or=20 so?   I don't have the measurements)
 
So I do buy the argument that at low = throttle=20 settings, and under normal circumstances, you aren't going to have much = residual=20 pressure in the cabin.   But there are lots of possible = failure modes=20 here:  a) pressure controller malfunction b) pressure controller = set way=20 below landing altitude c) exhaust valve is not operating correctly - not = enough=20 cabin exchange rate.  These may argue for the pressure = switch
 
The suggestion I like the best is = "check cabin=20 pressure before opening the door".
 
 

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