X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 03 May 2010 14:10:46 -0400 Message-ID: X-Original-Return-Path: Received: from vms173015pub.verizon.net ([206.46.173.15] verified) by logan.com (CommuniGate Pro SMTP 5.3.6) with ESMTP id 4245631 for lml@lancaironline.net; Mon, 03 May 2010 09:32:22 -0400 Received-SPF: none receiver=logan.com; client-ip=206.46.173.15; envelope-from=mnewman@dragonnorth.com Received: from PCMIKE3 ([unknown] [72.70.56.213]) by vms173015.mailsrvcs.net (Sun Java(tm) System Messaging Server 7u2-7.02 32bit (built Apr 16 2009)) with ESMTPA id <0L1U009M6IWDQ140@vms173015.mailsrvcs.net> for lml@lancaironline.net; Mon, 03 May 2010 08:31:30 -0500 (CDT) Reply-to: From: "Michael Newman" X-Original-To: References: In-reply-to: Subject: RE: L-IV engine vibration X-Original-Date: Mon, 03 May 2010 09:31:23 -0400 X-Original-Message-id: <032d01caeac4$ef712620$ce537260$@com> MIME-version: 1.0 Content-type: text/plain; charset=us-ascii Content-transfer-encoding: 7bit X-Mailer: Microsoft Office Outlook 12.0 Thread-index: AcrqK6I+IRPljSQARfGXa7Fq5nV1wQAmLMYw Content-language: en-us I had a similar problem that occurred above 21K. Turned out to be in the Mags. Internal arcing occurred. Pressurizing the Mags is required to prevent this (for some reason pressurized air is a better insulator). Once the arcing starts you have to replace some parts to get rid of it. There are some small holes that are supposed to be open for drainage. Apparently it is a well known and documented issue that these holes plug up. If the Mags do not vent properly then moisture accumulates and provides a path for arcing. We could not tell if this was my root cause.