X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Thu, 08 Apr 2010 21:13:30 -0400 Message-ID: X-Original-Return-Path: Received: from web57510.mail.re1.yahoo.com ([66.196.100.77] verified) by logan.com (CommuniGate Pro SMTP 5.3.5) with SMTP id 4214107 for lml@lancaironline.net; Thu, 08 Apr 2010 06:25:23 -0400 Received-SPF: none receiver=logan.com; client-ip=66.196.100.77; envelope-from=casey.gary@yahoo.com Received: (qmail 16258 invoked by uid 60001); 8 Apr 2010 10:24:47 -0000 DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Message-ID:X-YMail-OSG:Received:X-Mailer:References:Date:From:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=Y4JU4p2nLyi5za/9zIHK/shKrhtfWv4XrvrNH2msujRwfAJADnq01WI5pcndgdC/rOH2n0vWDa9kV6ZmuNxaZo8d2IOtUI8qW2pSgwBrOl4XvnlLsG2AxC4AQTKEK0NWhWEsOAbnvwcmWSxblJei0mwHN3ZBtVw1LqVj/lo+aHA=; X-Original-Message-ID: <206514.11567.qm@web57510.mail.re1.yahoo.com> X-YMail-OSG: xaVqBkcVM1k.8K1pUpGsuhd6mUcjzoFpy_avOgEyIopAs7s WGRMIrwcOphQ2DRNbJLYSnlVbegu1vqCxFzJL6GCAK7mQg9jhk9FTBV.oXBP wiQDHCClvbedpwburrg2c3mtUfVRErtDgZrkoMd0F0rzU8HQWEkMZoW7mEda .jUwsnu86PWbvSwQKxtru.djPJfYArwlyBqPpjfFRXu9CAjyyaL8yphx2KqD RsuSHlPnBDXm7CBaKkz.pA7UQNMRWx17EeVjHtEJkUow2zhJ0xA9zmELqeGK A8Pl24M1IB0ndWth8FtIDzQuayMdVwL2X7BxVXi8p6qzZA4dD2ETxTlQ- Received: from [97.122.178.37] by web57510.mail.re1.yahoo.com via HTTP; Thu, 08 Apr 2010 03:24:47 PDT X-Mailer: YahooMailRC/324.3 YahooMailWebService/0.8.100.260964 References: X-Original-Date: Thu, 8 Apr 2010 03:24:47 -0700 (PDT) From: Gary Casey Subject: Re: fixes for S-TEC 50 alt hold X-Original-To: Lancair Mailing List In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-2135430846-1270722287=:11567" --0-2135430846-1270722287=:11567 Content-Type: text/plain; charset=us-ascii I don't know whether or not it's related, but in my Cardinal I had a problem with my S-TEC altitude hold when it (the autopilot) was new. The altitude hold function was divergently unstable - would start to oscillate and then get worse and worse. Tried all sorts of static systems and finally disconnected the static source entirely and used cabin pressure - seemed to work slightly better. I was going back and forth with the factory -they initially insisted there was "no problem" and said I should take it back to the installer to have them fix their installation. Then I broadcast the problem on the net and received replies from all over the world about the same problem. I sent copies to S-TEC and they immediately said "send it in," so I did. It came back with no documentation so I called: "We just checked it out and found no problem." Oh, yeah? I installed it and it worked perfectly. All the earlier S-TEC autopilots, including the 55, used analog circuitry, so the change gain components had to be changed. They never did admit they had a problem, but I'll bet after that a lot of owners sent theirs back for the same "inspection." Gary ES with TruTrack ________________________________ To: "" one other comment on the static source: the a/p doesn't care how accurate the static source is, only that it changes with altitude. Therefore some people have found that (on spam cans) putting a dedicated static port in just for the pressure transducer works well. ...or you can just use the vents to fine tune your altitude.... --0-2135430846-1270722287=:11567 Content-Type: text/html; charset=us-ascii
I don't know whether or not it's related, but in my Cardinal I had a problem with my S-TEC altitude hold when it (the autopilot) was new.  The altitude hold function was divergently unstable - would start to oscillate and then get worse and worse.  Tried all sorts of static systems and finally disconnected the static source entirely and used cabin pressure - seemed to work slightly better.   I was going back and forth with the factory -they initially insisted there was "no problem" and said I should take it back to the installer to have them fix their installation.  Then I broadcast the problem on the net and received replies from all over the world about the same problem.  I sent copies to S-TEC and they immediately said "send it in," so I did.  It came back with no documentation so I called:  "We just checked it out and found no problem."  Oh, yeah?  I installed it and it worked perfectly.  All the earlier S-TEC autopilots, including the 55, used analog circuitry, so the change gain components had to be changed.  They never did admit they had a problem, but I'll bet after that a lot of owners sent theirs back for the same "inspection."
Gary
ES with TruTrack

To:
"" <lml@lancaironline.net>
one other comment on the static source:   the a/p doesn't care how accurate the static source is, only that it changes with altitude.   Therefore some people have found that (on spam cans) putting a dedicated static port in just for the pressure transducer works well.
 
...or you can just use the vents to fine tune your altitude....

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