X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 05 Sep 2011 17:14:34 -0400 Message-ID: X-Original-Return-Path: Received: from mail-iy0-f180.google.com ([209.85.210.180] verified) by logan.com (CommuniGate Pro SMTP 5.4.1) with ESMTPS id 5113813 for lml@lancaironline.net; Sun, 04 Sep 2011 22:46:31 -0400 Received-SPF: none receiver=logan.com; client-ip=209.85.210.180; envelope-from=dico@internetworks.ca Received: by iabz7 with SMTP id z7so7795654iab.25 for ; Sun, 04 Sep 2011 19:45:56 -0700 (PDT) MIME-Version: 1.0 Received: by 10.42.115.131 with SMTP id k3mr3099264icq.511.1315190756001; Sun, 04 Sep 2011 19:45:56 -0700 (PDT) Received: by 10.42.169.129 with HTTP; Sun, 4 Sep 2011 19:45:55 -0700 (PDT) X-Original-Date: Sun, 4 Sep 2011 23:45:55 -0300 X-Original-Message-ID: Subject: Figuring out the pressurization system IV-P -- couple of questions From: Dico Reijers X-Original-To: lml Content-Type: multipart/alternative; boundary=20cf303ea740d2ca2804ac28b517 --20cf303ea740d2ca2804ac28b517 Content-Type: text/plain; charset=ISO-8859-1 Hi All, Today I was up flying and figuring out the pressurization system. Things like if the annunciator panel / warning horn would sound if the "dump" switch was in the on (don't pressurize position). As I climbed through 11,000' the horn and annunciator panel lit up. I could see that the system wasn't pressurized as the gauge indicated the cabin pressure at pretty much the same as our altitude (we were at 11k and the cabin showed 10k). The dial was set to the 1000' field elevation. I flicked the dump switch and the cabin immediately began to pressurize (I could feel it in my ears almost immediately after flicking the switch). I then climbed to 14000' to see how the system would react (Power setting 28" and 2300RPM). At 14,000' the pressurization horn went off again as the cabin pressure got to 10,000' again. I realized that I forgot to change the dial to my cruising altitude of 14,000', so I then dialed up 14000', thinking that the pressurization system would then pressurize to that new altitude --- but it didn't. It just stayed at a cabin pressure of 10k. I have a couple questions... 1) I presume the cabin pressurization should be set to my cruise altitude BEFORE I get there as turning the dial to my cruising altitude after I get there doesn't seem to work... is this right? 2) People have told me that I should set the pressurization 1000' above my actual cruising altitude and field elevation on landing... is this right? Whats the logic here? Thanks, Dico --20cf303ea740d2ca2804ac28b517 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Hi All,

Today I was up flying and figuring out the pressurization sy= stem.=A0 Things like if the annunciator panel / warning horn would sound if= the "dump" switch was in the on (don't pressurize position).=

As I climbed through 11,000' the horn and annunciator panel lit up.= =A0 I could see that the system wasn't pressurized as the gauge indicat= ed the cabin pressure at pretty much the same as our altitude (we were at 1= 1k and the cabin showed 10k).=A0=A0 The dial was set to the 1000' field= elevation.=A0=A0=A0 I flicked the dump switch and the cabin immediately be= gan to pressurize (I could feel it in my ears almost immediately after flic= king the switch).=A0 I then climbed to 14000' to see how the system wou= ld react (Power setting 28" and 2300RPM).=A0=A0 At 14,000' the pre= ssurization horn went off again as the cabin pressure got to 10,000' ag= ain.=A0 I realized that I forgot to change the dial to my cruising altitude= of 14,000', so I then dialed up 14000', thinking that the pressuri= zation system would then pressurize to that new altitude --- but it didn= 9;t.=A0 It just stayed at a cabin pressure of 10k.

I have a couple questions...=A0

1)=A0 I presume the cabin press= urization should be set to my cruise altitude BEFORE I get there as turning= the dial to my cruising altitude after I get there doesn't seem to wor= k... is this right?

2)=A0 People have told me that I should set the pressurization 1000'= ; above my actual cruising altitude and field elevation on landing... is th= is right?=A0 Whats the logic here?

Thanks,

Dico
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