Return-Path: Sender: (Marvin Kaye) To: lml Date: Tue, 05 Nov 2002 07:58:19 -0500 Message-ID: X-Original-Return-Path: Received: from vineyard.net ([204.17.195.90] verified) by logan.com (CommuniGate Pro SMTP 4.0) with ESMTP id 1853131 for lml@lancaironline.net; Tue, 05 Nov 2002 06:19:07 -0500 Received: from direct (FSY6.VINEYARD.NET [66.101.65.6]) by vineyard.net (Postfix) with SMTP id B1A58915C2 for ; Tue, 5 Nov 2002 06:18:48 -0500 (EST) X-Original-Message-ID: <002801c284bd$4aa04ce0$06416542@direct> From: "Ted Stanley" X-Original-To: "Mail List Lancair" Subject: re: STEC autopilot experience X-Original-Date: Tue, 5 Nov 2002 06:15:35 -0500 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 As Doug Johnson mentioned it may be control stiffness encountered at altitude resulting from either the effects of pressurization on the controls or colder temperatures aloft. I once flew a Seneca III out of Rochester NY on a COLD winter night and after I climbed to about 9000 msl the autopilot kicked off and I could barely move the elevator (stabilator actually) trim. The problem turned out to be that I had lubricated the trim jackscrew with the wrong kind of grease ! After cleaning the trim jackscrew and drum and relubricating it with the proper low temp grease the problem never happened again. I agree with Charlie Kohler, you may have servos with slipping clutches but I can't say I'd recommend just increasing the servo torque to overcome another more basic problem. Ted Stanley - A&P-IA