Return-Path: Sender: "Marvin Kaye" To: lml@lancaironline.net Date: Tue, 08 Feb 2005 11:53:57 -0500 Message-ID: X-Original-Return-Path: Received: from wind.imbris.com ([216.18.130.7] verified) by logan.com (CommuniGate Pro SMTP 4.3c1) with ESMTP-TLS id 720349 for lml@lancaironline.net; Tue, 08 Feb 2005 11:20:52 -0500 Received-SPF: none receiver=logan.com; client-ip=216.18.130.7; envelope-from=brent@regandesigns.com Received: from [192.168.1.100] (vsat-148-63-101-227.c002.t7.mrt.starband.net [148.63.101.227]) (authenticated bits=0) by wind.imbris.com (8.12.11/8.12.11.S) with ESMTP id j18GJ98w008652 for ; Tue, 8 Feb 2005 08:19:14 -0800 (PST) (envelope-from brent@regandesigns.com) X-Original-Message-ID: <4208E674.1020304@regandesigns.com> Disposition-Notification-To: Brent Regan X-Original-Date: Tue, 08 Feb 2005 08:19:00 -0800 From: Brent Regan User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.2) Gecko/20040804 Netscape/7.2 (ax) X-Accept-Language: en-us, en MIME-Version: 1.0 X-Original-To: Lancair Subject: Re: Brain Lock Content-Type: multipart/alternative; boundary="------------010305030704070307080506" This is a multi-part message in MIME format. --------------010305030704070307080506 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Jeff writes: <> Jeff is correct in that there are ways to induce undetectable erroneous readings in the EFIS sensors. Placing a ferromagnetic component next to a magnetic flux sensor (compass) will induce an undetectable offset. It is undetectable because you have changed the "thing" that the sensor is measuring and the sensor is accurately reporting that change. The pilot should detect the problem when taxing the airplane on a known heading. Likewise with a leaky or blocked air data system. As good as these systems get there is always a need for the pilot to verify the "big picture". Regarding overheating, the experimental systems will shut down if overheated. The certified systems will give a 5 degree C warning. The certified and experimental share similar low level thermal protection systems but the certified system has additional layers of protection and the hooks needed to report the actual Pentium die temperature to the application software. In either case, the potential for overheating should be identified during post installation checkout. Proper prior planning prevents piss poor performance. Regards Brent Regan --------------010305030704070307080506 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit Jeff writes:
<<For instance, place a steel tow bar near your AHARS and watch the heading go buggy-- no annunciation. Let the Chelton screen overheat. It will shut off-- sayonara bubba-- with no warning.>>

Jeff is correct in that there are ways to induce undetectable erroneous readings in the EFIS sensors. Placing a ferromagnetic component next to a magnetic flux sensor (compass) will induce an undetectable offset. It is undetectable because you have changed the "thing" that the sensor is measuring and the sensor is accurately reporting that change. The pilot should detect the problem when taxing the airplane on a known heading. Likewise with a leaky or blocked air data system. As good as these systems get there is always a need for the pilot to verify the "big picture".

Regarding overheating, the experimental systems will shut down if overheated. The certified systems will give a 5 degree C warning. The certified and experimental share similar low level thermal protection systems but the certified system has additional layers of protection and the hooks needed to report the actual Pentium die temperature to the application software. In either case, the potential for overheating should be identified during post installation checkout.

Proper prior planning prevents piss poor performance.

Regards
Brent Regan
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