From: "Marvin Kaye" <marv@lancaironline.net>
Subject: Re: [LML] Re: VistaNav
To: lml
Date: Wed, 19 Jul 2006 04:23:05 -0400
Message-ID: <web-1283040@logan.com>
In-Reply-To: <000b01c6aae9$2adf0a80$650610ac@jacky0da39824a>
References: <list-1281279@logan.com>
 <000b01c6aae9$2adf0a80$650610ac@jacky0da39824a>
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Posted for "Tom Gourley" <tom.gourley@verizon.net>:

  "The 10,000 ft altitude limit of any of the Motion based systems is a 
SERIOUS
limitation"
  
  Matt,
  
  Good observation.  The specs for the system are a bit puzzling.  The 
Inertial
Navigation Unit, one of the two boxes that makes up a complete system, has
reasonable specs; up to 24,000 feet and operating temperature from 32F to
105F.  The other box, essentially a tablet PC, is rated for up to 10,000 feet
and an operating temp range of 41F to 95F.  As you've pointed out 10,000 feet
is simply not adequate, even for us normally aspirated pilots.  On the other
hand, those specs are pretty typical for a notebook or tablet PC.  Being a
computer hardware guy myself I suspect that's simply what the tablet PC
manufacturer set as their requirement, validated the PCs operation over that
range and called it good.  Does this mean the tablet, or Mobile Computing
Platform as it's called, will stop working above 10,000 feet.  I doubt it.
  Would I bet my life on it.  Heck no!  I think Mercury needs to validate
operation at a higher altitude for this system to be taken seriously.  Many
times the altitude limitation for a computer is due to reduced cooling
efficiency at thelower air density.  I've seen specs on some computer systems
that derate the maximum operating temperature at higher altitudes.  Maybe they
could do something similar with the VistaNav.
  
  Tom