Jepp vs. FAA data quality (was: Re: Subscription to NASD CD-ROM (was: embedded ...))

[Brian Lloyd <brian@lloyd.com>]

At 02:24 PM 2/10/00 -0800, Andy Ross <andy@mail.office.nextbus.com> wrote:
>I think you just showed us the reason:  Jepp data is _perceived_ as more
>accurate (because everybody uses it, of course).  Since the database
>cost is a small fraction of the unit cost for a GPS receiver, and
>especially since the maintenance cost of upgrades isn't the problem of
>the manufacturer (the user has to pay for them), the manufacturers just
>use Jepp data by default and write off the extra cost as "advertising".

Well, that isn't how it worked last time I looked (about 1.5 years ago --
remember that I started this process with Jepp for my project).  The
manufacturer has to specify the subset of data that they want from
Jeppesen.  Jepp then cuts them a custom tape.  The manufacturer then has to
burn their own datacards or floppies and then keep track of who has
received them so that they can send their per-user payments back to Jepp.
It is ugly and I would bet that the manufacturers would drop Jepp like a
hot potato if they could.  In fact, Jepp was working on a deal whereby they
would sell database updates directly to the end-user thus reducing the
hassle for the manufacturers and increasing their (Jepp's) margins.  If
they were doing that then I would agree with you but I haven't noticed that
Jepp was doing direct sales of database info to the end users ... yet.  I
suspect that the manufacturers decided that they still want a piece of the
action since it generates recurring revenue for them.

>Mind you, _I_ haven't looked at the data for discrepancies, but I'd be
>a little worried if the government data was actually _wrong_.  It's the
>same data that goes into the NOS charts and approach plates, isn't it?

No, it is not, at least it wasn't a year or so ago.  Like you, I assumed
that the NOS charts and plates were generated from the FAA data so I
contacted the folks at cartography in NOS (the folks who generate the NOS
charts).  At that time the NOS charts and approach plates were still
hand-generated.  But we know that the federal government works at a
blinding pace adopting new technology so I am certain that you are right
and they have switched over to automatic generation of charts and approach
plates from the database at this point.  :^Q

>Since NOS users aren't flying into the ground any more than Jepp folks
>(I presume -- if this isn't true I smell a HUGE class action lawsuit
>brewing), I argue that this is an existance proof that the Jeppesson
>database is no better than the FAA one.

The fatal flaw in your proof is that you assume that the feds are doing
something rational and using their own database without correction.  And
even so, you are probably assuming that, if the guys drawing the charts
noted a discrepency in the data, the corrections or at least notification
of the errors would be forwarded back to the keepers of the database.
Government coordination for the purposes of efficiency and correctness?
Hahahahahahahahahahahahahahahahahahahahahahaha!


Brian Lloyd                                    Lucent Technologies
brian@lloyd.com                                3461 Robin Lane, Suite 1
http://www.livingston.com                      Cameron Park, CA  95682
+1.530.676.6513 - voice                        +1.530.676.3442 - fax

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