Re: New ground proximity warning.

Date:         08 Dec 96 04:12:41 
From: (C. Marin Faure)
Organization: Northwest Nexus Inc.
References:   1 2
Followups:    1 2
Next article
View raw article
  or MIME structure

In article <airliners.1996.2679@ohare.Chicago.COM>, (Robert
Dorsett) wrote:

> In article <airliners.1996.2584@ohare.Chicago.COM>
(C. Marin Faure) writes:
> >I had an opportunity to see an Alaska Airlines internal communication
> >video yesterday, and they described a new terrain avoidance system that I
> >think is pretty slick.  It is being installed on their 737-400s and will
> >undoubtedly be a feature of their new 737s as well.
> >
> >A very accurate terrain map of an area-- in the example on the tape it was
> >Juneau, Alaska-- is put on a CD-ROM.
> Not to sound trite, but the reliability of such a system is directly related
> to the quality of data which goes into it.  I can't help but think of the
> large number of "uncharted" swatches on every Cali crash chart I've seen
> thus far.  And any cartographer is aware of the huge number of "design
> compromises" which go into map-making, and the amount of fudging (inter-
> polation between data points, etc) that goes on.

After submitting my post I got a phone call from someone who is involved
in the development of this system.  Apparently, there is a wealth of
topographical satellite data that has been "stored" away for military
reasons by governments around the world.  This data is now being released
by many of these governments and is one of the sources for the
topographical data being used in the enhanced proximity warning system I

So on the one hand, the potential database for mapping information is
quite extensive and quite accurate.  On the other hand, there are still
governments-- I was told that some of them are in South America and
another is North Korea-- that have refused to release their topographical
data.  So until the database is worldwide, there will be areas in which
the accuracy is less than ideal.

I agree that relying on a new, gee-whiz technology or systems is not a
guarantee of safety.  But anything that gives the pilots more information
about their airplane's relationship to the potential terrain dangers
around them is a good thing as far as I'm concerned, and well worth the
cost and effort to install.  Apparently, this same system is being
installed by American Airlines and United as well as Alaska.  I wish I had
it in the de Havilland Beaver floatplane I fly.  But I can't complain; at
least it has a com radio...

C. Marin Faure
   author, Flying a Floatplane