[time-nuts] Crossing International Date line causes F-22Jet Problems

Rob Kimberley rk at timing-consultants.com
Thu Apr 12 12:27:09 EDT 2007

Nice web site!!

Rob Kimberley 

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Brendan Minish
Sent: 12 April 2007 12:12
To: time-nuts at febo.com
Subject: Re: [time-nuts] Crossing International Date line causes F-22Jet

Noting to do with time keeping but a number of years ago I was involved with
a Voyage thought the North West passage 

The Autopilot in use on the boat works by learning it's corrections for
local magnetic deviation from the GPS system by watching the course. It
steers by Fluxgate compass but updates heading and compass deviations based
on GPS data when set to steer a GPS track

The Controller unit in the autopilot died and never recovered from trying to
correct for magnetic north being almost due south of current position and
having a southerly course set whilst being north of the magnetic North Pole.

The manufacturer never admitted a programming 'issue' but we did get a
replacement controller once the north west passage voyage was over.
We had no issues on the North east passage but of course the deviations on
that voyage would not have created the same problem

you can read about these journeys at
You will have to dig a bit for the North west passage journey 

Brendan EI6IZ 

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