Message-Id: <s5f657f2.026@YCC.COM>
Date: Wed, 09 Sep 1998 10:26:33 -0500
From: "Bill Gradwohl" <Bill@YCC.COM>
To: lancair.list@olsusa.com
Subject: Y2K & GPS problems
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Since everyone that will receive this is involved in aviation, I thought the 
following information would be appropriate to share with all of you.

If you point your WEB browser at http://tycho.usno.navy.mil/gps_week.html 
you will find some information about a Y2K related problem that will actually
show up August 22, 1999. This is a US Navy WEB site so take the information
seriously.

What the Navy says is that many GPS receivers will fail to supply proper time 
and/or position information after August 22, 1999. The reason for this is 
very similar to the main Y2K problem. Years ago, when the GPS system was 
first set up, someone decided to use a small field to record the number of 
weeks that have elapsed. On August 22, 1999 that field rolls over back to 0 
and some GPS receivers will think it's 1980. 

Time and date are critically important to determine position information. If a 
GPS receiver thinks it's 1980, it will not accurately reflect the true position.
Consider checking with your equipment manufacturer to see if your GPS
unit will exhibit the problem next year.

You may be asking how this ties in with the Y2K phenomenon. 

You can read about this problem at www.garynorth.com under the BANKING 
section. Or go directly to the information by pointing your browser at
http://www.garynorth.com/y2k/detail_.cfm/137 

I've been in the computer business for over 25 years, and wrote lots of code
in the 70's and 80's that has the Y2K problem. It wasn't my choice as to how
the code got written. I know the problem is real and I would urge everyone
to spend some time determining their individual exposure.

Bill Gradwohl
IV-P N858B