Return-Path: Received: from tomts7-srv.bellnexxia.net ([209.226.175.40]) by ns1.olsusa.com (Post.Office MTA v3.5.3 release 223 ID# 0-64832U3500L350S0V35) with ESMTP id com for ; Sun, 31 Dec 2000 20:27:57 -0500 Received: from laurentian ([206.172.211.108]) by tomts7-srv.bellnexxia.net (InterMail vM.4.01.03.00 201-229-121) with SMTP id <20010101013559.XCWI1081.tomts7-srv.bellnexxia.net@laurentian> for ; Sun, 31 Dec 2000 20:35:59 -0500 From: "Gary Rodgers" To: "Lancair List" Subject: alternators/brushes Date: Sun, 31 Dec 2000 20:39:36 -0500 Message-ID: Importance: Normal X-Mailing-List: lancair.list@olsusa.com Reply-To: lancair.list@olsusa.com Mime-Version: 1.0 <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> >> Walter, thanks for adding the item I was missing in my caution regarding automotive alternators. I knew it had something to do with the brushes, and electrical arcing at altitude. An alternator with a good internal dusting of conductive graphite particles is the perfect environment for internal arcing to occur at higher altitudes where the insulating properties of the air is less. (Why do most, if not all, pressurized piston engine aircraft have pressurized mags? To limit the potential for internal arcing) Its especially critical when so many people are abandoning vacuum driven equipment in favor of 'more reliable electric' driven instrumentation. Compromising/reducing reliability of the sole electrical source when it is going to be your sole 'life line' is not where I want to save money. Most Lancair builders are building 'high performance' aircraft; at least relative to most other experimental categorized aircraft. Performance either costs now or later: now it is in materials, later could be a life. As I mentioned in my previous post, lower performance aircraft will probably not be so affected because they will not be taken to the higher altitudes, probably will not be flown through multiple weather systems on a long cross country, etc, and the survival of a 'day vfr' failure is very likely. Make it a happy new year!! It doesn't just happen. Gary Rodgers >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> LML website: http://www.olsusa.com/Users/Mkaye/maillist.html LML Builders' Bookstore: http://www.buildersbooks.com/lancair Please send your photos and drawings to marvkaye@olsusa.com. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>