Return-Path: Sender: (Marvin Kaye) To: lml Date: Fri, 06 Jun 2003 12:51:33 -0400 Message-ID: X-Original-Return-Path: Received: from [148.78.247.24] (HELO cepheus.email.starband.net) by logan.com (CommuniGate Pro SMTP 4.1b7) with ESMTP id 2405262 for lml@lancaironline.net; Fri, 06 Jun 2003 12:26:56 -0400 Received: from regandesigns.com (vsat-148-63-101-227.c002.t7.mrt.starband.net [148.63.101.227]) by cepheus.email.starband.net (8.12.9/8.12.9) with ESMTP id h56GQqdU005106 for ; Fri, 6 Jun 2003 12:26:55 -0400 X-Original-Message-ID: <3EE0C160.6000105@regandesigns.com> Disposition-Notification-To: Brent Regan X-Original-Date: Fri, 06 Jun 2003 09:29:20 -0700 From: Brent Regan User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.0.2) Gecko/20021120 Netscape/7.01 X-Accept-Language: en-us, en MIME-Version: 1.0 X-Original-To: Lancair Subject: Re: Recent SC Crash Content-Type: multipart/alternative; boundary="------------060501090609090207020902" --------------060501090609090207020902 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Valin writes: <> Not so strange. Once you exceed a certain pitch angle your EFIS screen (or gyro) will show all brown or all blue (just like your windshield). Unlike a gyro, the CFS system does retain a brown or green band along the edge of the display that indicates the fastest way to level flight. <> This is a good point but not likely as the data recorded is the data collected and displayed. The data collected is from several sources, AHRS, GPS, Airdata and Engine data. Analyzing the data allows you to cross check that the data is reasonable. For example, a reduction in airspeed at a continuous power setting will cause a rise in engine CHT. A momentary drop in oil pressure can indicate a negative G event. The data regarding this crash is in the hands of the NTSB and they will make a determination as to its conformity to reality. Regards Brent Regan --------------060501090609090207020902 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit Valin writes:

<<It seems strange, though, that an instrumented rated pilot can have a big SFS
display in front of him showing a large bank angle and still be so spatially
disoriented that he does not respond properly.  >>
Not so strange. Once you exceed a certain pitch angle  your EFIS screen (or gyro) will show all brown or all blue (just like your windshield). Unlike a gyro, the CFS system does retain a brown or green band along the edge of the display that indicates the fastest way to level flight. 


<<There is also a possibility that the very large multi-axis accelerations
from the severe turbulence disturbed the solid state AHRS enough that the
SFS was displaying a very corrupted flight attitude -- maybe the pilot
thought the wings were near level... so he's pulling on the stick, pulling
g's, confused that it's not slowing him down... high g's and high speed from
the steep bank and another big slap of turbulence...>>
This is a good point but not likely as the data recorded is the data collected and displayed. The data collected is from several sources, AHRS, GPS, Airdata and Engine data. Analyzing the data allows you to cross check that the data is reasonable. For example, a reduction in airspeed at a continuous power setting will cause a rise in engine CHT. A momentary drop in oil pressure can indicate a negative G event.

The data regarding this crash is in the hands of the NTSB and they will make a determination as to its conformity to reality.

Regards
Brent Regan

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