Return-Path: Sender: (Marvin Kaye) To: lml Date: Sat, 25 May 2002 09:55:33 -0400 Message-ID: X-Original-Return-Path: Received: from smtprelay2.dc3.adelphia.net ([24.50.78.5] verified) by logan.com (CommuniGate Pro SMTP 4.0b1) with ESMTP id 1247612 for lml@lancaironline.net; Sat, 25 May 2002 08:54:38 -0400 Received: from worldwinds ([207.175.254.66]) by smtprelay2.dc3.adelphia.net (Netscape Messaging Server 4.15) with SMTP id GWO3V200.1DE for ; Sat, 25 May 2002 08:54:38 -0400 From: "Gary Casey" X-Original-To: "lancair list" Subject: vacuum vs. electric X-Original-Date: Sat, 25 May 2002 05:50:55 -0700 X-Original-Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2910.0) Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 Lots of good posts on the subject - go to the "aero-electric" list as suggested by some to get multiple pro all-electric opinions. On my ES I am going to an electronic engine control, so it will have a redundant electrical system, but still a vacuum gyro. Why? Mostly because I have this (patented) pressure regulator that will operate vacuum gyros from a turbocharged engine (mine is) with no vacuum pump. So the plane will be sort of a flying test bed/tax write-off. Otherwise the all-electric scheme would maybe be the way I would go. However, I believe you can fly safely with the older, cheaper systems. Here's what I did on my Cessna for just that purpose: I have a vacuum system with no backup and a standard electrical system (also no backup). The backup for the vacuum system is my S-TEC autopilot, which I chose specifically because it is all-electric, getting it's information from the turn coordinator. The on/off button for the A/P is on the yoke so I don't have to reach for it. I consider that to be more effective backup than a backup vacuum system (more expensive, too - but the vacuum system won't fly the plane for me). I consider the A/P to be almost a no-go item for an IFR flight and I turn it on and check it on the ground as a pre-flight item. The A/P is also the backup for the other single-failure-mode system; me. I show regular right-seat passengers (my wife) how to turn on the A/P to level the wings. For my ES I plan to install the Autotrak A/P system which has internal electric gyros. I do change the vacuum pump every 700 hours for peace of mind, but I see no statistical proof that it is a good prevention. I've had both pump and instrument failures, including turn coordinators, over the years. Gary Casey ES project C177RG