X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 21 Mar 2008 17:58:38 -0400 Message-ID: X-Original-Return-Path: Received: from QMTA07.emeryville.ca.mail.comcast.net ([76.96.30.64] verified) by logan.com (CommuniGate Pro SMTP 5.2.1) with ESMTP id 2811177 for lml@lancaironline.net; Fri, 21 Mar 2008 01:34:17 -0400 Received-SPF: pass receiver=logan.com; client-ip=76.96.30.64; envelope-from=breskesen@comcast.net Received: from OMTA14.emeryville.ca.mail.comcast.net ([76.96.30.60]) by QMTA07.emeryville.ca.mail.comcast.net with comcast id 3gl81Z0011HpZEsA702J00; Fri, 21 Mar 2008 05:32:18 +0000 Received: from DHQY9Y81 ([71.226.63.81]) by OMTA14.emeryville.ca.mail.comcast.net with comcast id 3hZG1Z0061lAqKr8a00000; Fri, 21 Mar 2008 05:33:17 +0000 X-Authority-Analysis: v=1.0 c=1 a=S7vcOZcZX2VzvfIwzjsA:9 a=r2CdFkry8Rz1gr15h4YA:7 a=Lafuyn7SFnW1-9Bg8LBpObOLQYsA:4 a=HMmPKh5NLbsA:10 a=prw0jNNOqz3kTpcMVtUA:9 a=566-MXmVsygpomXUrVEA:7 a=lZeLOTSQo4eJBEIHcZve6cIBVGYA:4 a=AfD3MYMu9mQA:10 X-Original-Message-ID: <008c01c88b15$12eee7c0$6401a8c0@DHQY9Y81> From: "Eskesen" X-Original-To: "Lancair Mailing List" Subject: Gear wouldn't come up, LNC2 X-Original-Date: Thu, 20 Mar 2008 22:33:20 -0700 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0089_01C88ADA.662259D0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3198 This is a multi-part message in MIME format. ------=_NextPart_000_0089_01C88ADA.662259D0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Gerard, As Randy S points out, opening the dump valve merely equalizes the = pressure on both sides. But, it's a much lower pressure and therefore = allows the up pressure switch to stay open even when the fluid = temperature has increased substantially. I shut down the engine, turn = off the master, and then open the dump valve which I leave open while = parked. Remember that the landing gear has an over center mechanism on = each gear leg that locks the gear in the extended position. The gear = stays locked until hydraulic pressure is used to unlock the over center = mechanism(s) at the beginning of the retract cycle. If you were to open = the dump valve with the master switch on, the pump will run continuously = but will build no pressure till the valve is closed. For those of us = who occassionally have the pump not respond to the down switch while in = flight, opening the dump valve momentarilly will reduce the hydraulic = pressure that has built up during our flight through changing = temperatures, thus allowing the pump to come on and extending the gear. = Byron Eskesen ------=_NextPart_000_0089_01C88ADA.662259D0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Gerard,
 
As Randy S points out, opening the dump = valve=20 merely equalizes the pressure on both sides. But, it's a much lower = pressure and=20 therefore allows the up pressure switch to stay open even when the fluid = temperature has increased substantially.  I shut down the engine, = turn off=20 the master, and then open the dump valve which I leave open while = parked. =20 Remember that the landing gear has an over center mechanism on each gear = leg=20 that locks the gear in the extended position.  The gear stays = locked until=20 hydraulic pressure is used to unlock the over center mechanism(s) at the = beginning of the retract cycle.  If you were to open the dump valve = with=20 the master switch on, the pump will run continuously but will build no = pressure=20 till the valve is closed.  For those of us who occassionally have = the pump=20 not respond to the down switch while in flight, opening the dump valve=20 momentarilly will reduce the hydraulic pressure that has built up during = our=20 flight through changing temperatures, thus allowing the pump to come on = and=20 extending the gear. 
 
Byron = Eskesen
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