Re: Subscription to NASD CD-ROM (was: embedded ...)

[Brian Lloyd <brian@lloyd.com>]

At 06:46 PM 2/10/00 +0000, you wrote:
>Brian Lloyd wrote:
>> 
>> I am one of those sitting on the fence.  I was planning to use the Jeppesen
>> data for my experimentation since they provide a sample database
>> (incomplete but with examples of all the various record types) for testing.
>>  Jeppesen's data is the "cleanest", i.e. fewest errors in the DB.  I have
>> been told, second hand but by different consumers of the data for
>> commercial purposes, that the FAA data has a relatively high number of
>> errors and incorect data.
>
>Let me guess.. Jeppeson copyrights the data and charges a hefty sum so
>they can afford to buy the libility insurance and make a bit of
>profit...

That is correct.  They also augment the data so you will find more in the
Jepp DB than you will in the FAA DB.  You can also get international data
from Jepp.  This is not an advertisement for Jepp data but I thought that
the information would be a useful datum for people here.  BTW, you can get
a sample of their database for something like $99 for experiementation.

>Some how, I seriously doubt there is much improvement in the data over
>what the Federal Government releases.  Seems to me that if Jeppeson does
>much more than reformat the data and clean up obvious errors, but they
>would be on the hook for anything they may have changed.  I seriously
>doubt Jeppeson has more accurate sources of data than the Feds, so the
>data they generate will be no differant than the Fed's.

If you recall, it was Jeppesen that started the process of documenting
aviation data, not the CAA (now FAA).  They have information that the feds
do not.  If you contact them they will describe how they integrate and
filter the FAA data into their database.

>I'd bet, if we wrote a converter from the Fed data to the Jeppeson
>format, you would have very few differances.

Regardless of what I have said, if that were so, I suspect that the GPS
manufacturers would opt for the less expensive FAA data.  They don't and
that is universal.  Why do *ALL* the manufacturers use Jepp data?  There
must be a reason.

>How about we write such a software tool?  For us poor folks who cannot
>afford to pay Jeppeson for their data and whould be content running
>tools with the Fed data.

The Jepp data format is essentially the ARINC format (fixed-length,
mainframe-magtape-oriented data) with a few extensions.  If you get the
Jepp sample kit they include doc on all the record formats so you would
have that info.  It may be that the FAA is already using that format since
it is considered to be a standard in the aviation world.

>It would be fun to see how many changes Jeppeson really makes, and if
>their data is really more accurate.

With that many records it would be tough to prove unless you knew what to
look for.  Even so it sounds like an interesting project.


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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