NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Mike Mayer
Date: 2014 Apr 28, 20:06 -0500
I was on vacation and flew from Cambridge Bay to the mainland in Nunavut and when we were where the pilot thought should see the lodge that was our destination it was nowhere in sight. He eventually found it and I as I was looking at the chart I noticed that he had a mismatch between the format of lat/lon that he entered for the destination and the mode the GPS was in. I can’t remember which way it was out but it was either entered as decimal degrees and the GPS was in degrees/minutes/seconds or the other way around.
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Mike Mayer
From: NavList@fer3.com [mailto:NavList@fer3.com] On Behalf Of Gary LaPook
Sent: Monday, April 28, 2014 4:01 PM
To: mwmayer@tds.net
Subject: [NavList] Re: Researchers spoof GPS signals to alter superyacht'scourse
That report makes fantastic reading and is a textbook case of how navigation should be done but isn't. If the captain had required the bridge crew to plot hourly fixes, alternately from the GPS and from the LORAN, the error would surely have been found. Start reading at page 30 (page 38 of the PDF). ( There was an error in the original posted URL, one too many "dots" after the "www", I corrected it below.)
It reminds me of a time when I was co-pilot ferrying a Citation jet to Nebraska for a paint job. The captain asked me what I was doing about half way there. I said we were over a certain town (I don't remember which one) and that I was going to do do a ground speed check over the next visible town with my trusty E-6B to ensure that we had enough fuel on board to make it to our destination. She said that wasn't necessary, all the onboard nav equipment said we were ok. I said I still like to do an independent check, it just makes me happy. Turned out there was no problem but it still just makes me happy to have an independent check of the navigation.
gl
From: Peter Smith <NoReply_PeterSmith@fer3.com>
To: garylapook---.net
Sent: Monday, April 28, 2014 12:26 PM
Subject: [NavList] Re: Researchers spoof GPS signals to alter superyacht'scourse
> ... But what a poor navigator, not to use "all available information" (eg compass headings).
Sadly, nothing new. Remember the cruise ship _Royal Majesty_, which went aground east of Nantucket in 1995 because the GPS antenna was disconnected and the nav computer reverted to DR. During the entire trip from Bermuda, not one watch officer noticed that the position display was showing an error code, nor did anyone use any of the other available means (LORAN-C, Transit/SatNav, and celestial) to verify what was on the screen. Oh, and the fathometer, which could have warned of unexpected shoaling, was turned off.
See http://www.ntsb.gov/doclib/reports/1997/mar9701.pdf
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