Return-Path: Sender: (Marvin Kaye) To: lml Date: Fri, 24 May 2002 18:30:44 -0400 Message-ID: X-Original-Return-Path: Received: from smtp03.mrf.mail.rcn.net ([207.172.4.62] verified) by logan.com (CommuniGate Pro SMTP 4.0b1) with ESMTP id 1246642 for lml@lancaironline.net; Fri, 24 May 2002 08:14:55 -0400 Received: from 208-59-158-95.s95.tnt2.frdb.va.dialup.rcn.com ([208.59.158.95] helo=OFFICE) by smtp03.mrf.mail.rcn.net with smtp (Exim 3.33 #10) id 17BDyA-0005qR-00; Fri, 24 May 2002 08:14:55 -0400 X-Original-Message-ID: <00bf01c2031c$b23c5060$5f9e3bd0@OFFICE> From: "Bill & Sue" X-Original-To: "Lancair Mailing List" , References: Subject: Re: [LML] Vacuum v. all electric X-Original-Date: Fri, 24 May 2002 08:15:28 -0400 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 > 1. What are most folks doing in their planes? Hi Dan, There are certainly valid arguments to be made for many different combinations of instrument power. Here's what we did in our 320 and I'm quite satisfied with the level of redundancy. We used vacuum horizon and DG and electric for the turn coordinator which is also the autopilot (Stec 30). We then provided a backup for each system, vacuum and electric. For the vacuum we used the precise flight manifold type system. You certainly wouldn't want to PLAN to be IFR with this system in use but I believe that it is an excellent EMERGENCY system. It's light, fairly easy to install and economical. For electric we have two electrical systems, a main bus and an essential bus. Instead of the usuall single 25AH battery we used two 12AH (B&C) batteries. Each battery powers it's own bus. For normal operations, the busses are connected by a bus tie contactor. In the event of an alternator failure, the bus tie would be opened and the systems would seperate. Having only truly ESSENTIAL stuff on the essential bus assures that we would have electricity to that bus for about 4 hours in the event of an alternator failure. The weight of this dual battery system is just slightly more than a single battery system yet it provides, in my opinion, adequate redundancy for serious IFR operation. I'm sure that there are many other good ideas out there, this one works for us. Bill & Sue harrelson@erols.com N5ZQ