X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [64.4.51.88] (HELO hotmail.com) by logan.com (CommuniGate Pro SMTP 4.3.4) with ESMTP id 988080 for flyrotary@lancaironline.net; Tue, 07 Jun 2005 22:29:49 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.4.51.88; envelope-from=lors01@msn.com Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Tue, 7 Jun 2005 19:28:54 -0700 Message-ID: Received: from 64.4.51.220 by BAY107-DAV16.phx.gbl with DAV; Wed, 08 Jun 2005 02:28:54 +0000 X-Originating-IP: [64.4.51.220] X-Originating-Email: [lors01@msn.com] X-Sender: lors01@msn.com From: "Tracy Crook" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: EC2 dual power feeds Date: Tue, 7 Jun 2005 22:28:47 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0165_01C56BB0.45B17100" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: MSN 9 X-MIMEOLE: Produced By MSN MimeOLE V9.10.0011.1703 Seal-Send-Time: Tue, 7 Jun 2005 22:28:47 -0400 X-OriginalArrivalTime: 08 Jun 2005 02:28:54.0704 (UTC) FILETIME=[D0E6A300:01C56BD1] This is a multi-part message in MIME format. ------=_NextPart_000_0165_01C56BB0.45B17100 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MessageThanks Ian, you got it right. In my informal look at the number = of scrubbed space shuttle missions, far more are canceled due to faults = in the failure detection systems than for actual system failures. =20 It seemed like a reasonable requirement to have the pilot switch = controllers if he suspected a problem. Yes, always possible for a = failure to occur at the worst possible moment on takeoff, no time to = switch, yadda, yadda, etc. No time to mount a technical defense on = this so I'll summarize by saying that it is better to fly a good plane = than to dream about a perfect one. =20 Tracy=20 From: Ian Dewhirst=20 Technically the failed CPU is off ;-) I thought the pilot was the = third CPU. In order to have truly redundant EC2s would require a 3rd CPU to = monitor the two controllers and automatically switch the failed unit = off. Then what is going to monitor the 3rd computer? Wendell ------=_NextPart_000_0165_01C56BB0.45B17100 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message
Thanks Ian, you got it right.   In my = informal look at=20 the number of scrubbed space shuttle missions, far more are canceled due = to=20 faults in the failure detection systems than for actual system = failures. =20
 
It seemed like a reasonable requirement to have the pilot = switch=20 controllers if he suspected a problem.  Yes, always possible for a = failure=20 to occur at the worst possible moment on takeoff, no time to switch, = yadda,=20 yadda, etc.   No time to mount a technical defense on this so = I'll=20 summarize by saying that it is better to fly a good plane than to dream = about a=20 perfect one. 
 
Tracy
 

Technically the failed CPU is = off=20 ;-)  I thought the pilot was the third CPU.
In order to have truly redundant EC2s = would require=20 a 3rd CPU to monitor the two controllers = and=20 automatically switch the failed unit off.  Then what is going = to=20 monitor the 3rd computer?
Wendell
=
 
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