From: Sky2high@aol.com
Message-ID: <46.a7aae3a.26ef8d94@aol.com>
Date: Tue, 12 Sep 2000 09:45:56 EDT
Subject: Sierra Flight System Gyros
To: lancair.list@olsusa.com
Reply-To: lancair.list@olsusa.com
Mime-Version: 1.0

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Brent,

Thanks for the info on Crossbow.  You said <
<<<
Sierra Flight Systems flight tested the Crossbow AHRS and found that there
were two problems that made it unacceptable. First, it's maximum bandwidth
is only 10Hz, causing the attitude and heading display to be jerky. A higher
bandwidth is required for a smooth display. Second, the Crossbow system does
not have centripetal compensation. The result of this is that if you are in
a coordinated turn and then roll out to wings level, the Crossbow AHRS will
indicate a bank in the opposite direction of the turn. My inner ear already
has this feature, so I don't need it displayed.
>>>

My wife and I agree that I am totally insensitive so the x-bow would provide 
me with a display feature I don't need for IFR flight.  Too bad, it seemed 
like such a promising device.  Of course, the gyros we use today have the 
same feature, so don't be doing any steep turns in the clag.

<<<
It was my understanding at OSH that Meggit had dropped Crossbow and were now
using the same vendor at SFS. 
>>>

I was only there on the last Monday so I may have missed any late changing 
story.  Meggit complained that their AI/DG system at $40,000 was considered 
"cheap", therefore unworthy by the corporate jet set and I suggested that the 
rest of us in GA might think it was a bit pricey for the limited function it 
provided while taking up half the panel space.  Good luck S-Tec!

<<<
You can always tell the pioneers, they have arrows in their backs.
>>>

Oooow!  I hate when that happens. I always liked the ones that took it in the 
chest better.


Anyway,  thanks for the heads-up on x-bow and SFS.  Once again the worth of 
this forum has been shown to illuminate the dark and blurry corners of 
incomplete information.  Everyone should have the ultimate mission of their 
project in mind when they are considering its' complement of equipment.  For 
myself, I'm too old to be running someone else's experiments in addition to 
my own.

Scott Krueger
N92EX
Legacy # 2

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