X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 07 Feb 2011 07:45:22 -0500 Message-ID: X-Original-Return-Path: Received: from nm25-vm0.bullet.mail.ac4.yahoo.com ([98.139.52.240] verified) by logan.com (CommuniGate Pro SMTP 5.4c2a) with SMTP id 4840339 for lml@lancaironline.net; Sun, 06 Feb 2011 19:53:43 -0500 Received-SPF: none receiver=logan.com; client-ip=98.139.52.240; envelope-from=donaldgordon@bellsouth.net Received: from [98.139.52.197] by nm25.bullet.mail.ac4.yahoo.com with NNFMP; 07 Feb 2011 00:53:06 -0000 Received: from [98.139.52.142] by tm10.bullet.mail.ac4.yahoo.com with NNFMP; 07 Feb 2011 00:53:06 -0000 Received: from [127.0.0.1] by omp1025.mail.ac4.yahoo.com with NNFMP; 07 Feb 2011 00:53:06 -0000 X-Yahoo-Newman-Id: 712576.64508.bm@omp1025.mail.ac4.yahoo.com Received: (qmail 87112 invoked from network); 7 Feb 2011 00:53:06 -0000 Received: from BLUESKY (donaldgordon@98.85.48.110 with login) by smtp101.sbc.mail.ac4.yahoo.com with SMTP; 06 Feb 2011 16:53:06 -0800 PST X-Yahoo-SMTP: c.lEXFWswBCvgSVMJkTv6QMx90UyaRp2LlYBswHjRS_MKllxy0_1 X-YMail-OSG: 6yqwve8VM1m8oP0UWU3HozBFdmgHBtIw5WwpIl4l9miw2ib w2daLvoTnealUsbeM0HccAc0KlhBtisYJZIzTczk3dHOu8fC8QXIcrfMN7y0 OSRRGTz.H3wvRYafsgvdlI1tG1A9RbDyPIzYOuxRR6F3tEtyecX717eEjDhv iATuuItgj3LhDZFb5C8c3rbp.vnpyEyDnmAUp.p4G378EjtHTYN_VFGk17EH NGGEIH2Vmmv.G9b5F7M4UIGA7xB3_y_05nBjLvDQrHfoGRSvhEo6UNv2LhdZ gnh1yrGWKfgFIKhtCTZ74a1AC9M9W4QxNwA3JyiWBVbv9a6QQ5ZQK X-Yahoo-Newman-Property: ymail-3 From: "Don Gordon" X-Original-To: "Lancair Mailing List" Subject: LNC2 Hydraulic Landing Gear Pressure Switch Wear Issues X-Original-Date: Sun, 6 Feb 2011 19:53:04 -0500 X-Original-Message-ID: <02dd01cbc661$60e1cfd0$22a56f70$@bellsouth.net> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_02DE_01CBC637.780CB230" X-Mailer: Microsoft Outlook 14.0 Thread-Index: AcvGX14FEIuHCxtWR6qrlqtWlzskbQ== Content-Language: en-us This is a multipart message in MIME format. ------=_NextPart_000_02DE_01CBC637.780CB230 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit I have recently replaced both my high pressure and low pressure switches in the hydraulic system for the landing gear. These switches began to have trouble providing a positive and discrete on/off event when the hydraulic pressure reached the prescribed limits. I began to hear strange crackling and static noises in my headset just prior to the hydraulic pump running (though it would just run for a fraction of a second to re-pressurize). These strange sounds in my headset began to occur longer and longer prior to the pump tripping on. I also began to notice some other odd electrical issues with the aircraft. Finally, I began to suspect these switches were faulty are replaced both of them. The problem went away and so did my electrical issues I experienced. I suspect the pressures switches, as they age, begin to have difficulty providing a discrete on/off switching event and begin "bouncing". This "bouncing", or intermittent contact, wreaks havoc with your electrical system. It did not, however, show up on my voltmeter that I could discern. I certainly wish I would have replaced these switches long before they began exhibiting this behavior. Has anyone else had a similar experience? BTW, the initial pressure switches provided by the aircraft were not very good (1989 vintage). Since then, they were upgraded to a much better brand. The ones I most recently purchased from Lancair (I'm on my third set) appear to be even better than the ones I replaced. Only time and flight hours will tell how long they last. I'll be ready for them this time! Don Gordon Lancair 320, 1600 hours Orlando, FL ------=_NextPart_000_02DE_01CBC637.780CB230 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable

I have = recently replaced both my high pressure and low pressure switches in the = hydraulic system for the landing gear.  These switches began to = have trouble providing a positive and discrete on/off event when the = hydraulic pressure reached the prescribed limits.  I began to hear = strange crackling and static noises in my headset just prior to the = hydraulic pump running (though it would just run for a fraction of a = second to re-pressurize).  These strange sounds in my headset began = to occur longer and longer prior to the pump tripping on.  I also = began to notice some other odd electrical issues with the = aircraft.  Finally, I began to suspect these switches were faulty = are replaced both of them.  The problem went away and so did my = electrical issues I experienced.

 

I suspect = the pressures switches, as they age, begin to have difficulty providing = a discrete on/off switching event and begin = “bouncing”.  This “bouncing”, or = intermittent contact, wreaks havoc with your electrical system.  It = did not, however, show up on my voltmeter that I could discern.  I = certainly wish I would have replaced these switches long before they = began exhibiting this behavior.  Has anyone else had a similar = experience?

 

BTW, the initial pressure switches provided by the = aircraft were not very good (1989 vintage).  Since then, they were = upgraded to a much better brand.  The ones I most recently = purchased from Lancair (I’m on my third set) appear to be even = better than the ones I replaced.  Only time and flight hours will = tell how long they last.  I’ll be ready for them this = time!

 

 

Don = Gordon

Lancair 320, 1600 = hours

Orlando, = FL

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