The International Cessna^® 170 Association

Does anyone have experience with the Digital Download Obstacle File database^ or subscription?

*What information is included such as (AGL, Long/Lat)?
*How thorough is the database for towers compared to sectionals?
*What format is the database (tab delimited, excel, ascii)?

Thanks! -Randy

(^) Source: http://naco.faa.gov/ecomp/ProductDetail ... uctID=DDOF

Randy I have no first hand experience with that file but have dealt with other files available from the FAA. In most cases the files where available in some form that could be manipulated ie delimited text files. I would be surprised to find this different.

I would suspect the file you get will be just as accurate as a sectional because the sectional data is probably drawn from it. You will note one at least one of the descriptions it says the file contains obstacles the NACO knows about. Towers not meeting the requirement to be reported ie low towers such as cell phone towers will not be included.

I'm glad you pointed these files out as I was not aware of their availability.

Until recently I've done a lot of low level (under 800ft agl) with a G496 and am amazed at how many towers and terrain it points out. Much more than a sectional. I wonder where that data comes from?

Oh and for those wondering I still do a lot of low level flying but without the G496 as our chief pilot has removed them from our cockpit thinking it some sort of black magic.

I'm glad to know that in "most cases the files where available in some form that could be manipulated." I really like to double check these things.

This whole thing started with, I wonder where that data comes from? So I told my father that I could find it. After doing loads of searches and such, I came across that source. We use a Garmin 195 with some custom tower waypoints for my area, but the DDOF would be far superior. Although the memory is limited in my GPS, I could pull out the appropriate information. Thanks for the reply.

If anyone else checks out the Obstacle file, or has experience with the database, I would still like your comments, thanks!

-Randy

Can this Info be loaded on the 196 card?

John

John if the data is in a form like delimited text or ASCII then with the right knowledge and software the points can be loaded to hand held GPSs as way points. I do this all the time.

As for a data card in a 196 I'm not sure as I haven't worked with a GPS with a data card that I wanted to load. I believe but could be wrong that the data cards require the data to be compiled in a proprietary file that can not be read or made by the general public. That way the manufacturers can sell it to you.

Randy it the latest cycle was available I would have bought it for $4 and we would know the answer, unfortunately it was not.

Wow, found some more info on the FAA site browsing around... Maybe I simply over looked it, but I think it's just too scattered around. Anyways...

Good news...

1. This link has information on the digital obstacle file.
2. The link above also has a .DAT file example, and the file looks just like you described (being tab delimited or close to). Check it out. As far as my Garmin 195, I want to say that I can import ~200 custom waypoints, I'll have to double check, my dad has it now, next time I'm over there.

Bad news...
1. The FAA told me that the DOF is only availble in:
a.) A full DOF subscription for $28.00. I have a feeling that if the cycle was around this would be available for one time $4 purchase even though they said it wasn't. I may wait and see.
b.) In a bundle called DIGITAL AERO INFO CD-ROM which you can buy one time for $12.95. It comes with some other stuff (NAVAIDS and such). I suppose this is good news for me, because it's cheaper than the subscription.

Hope some of this helps you out, sorry I didn't research more thoroughly to begin with. I'll most likely grab the CDs just before spring rolls around, if I don't get antsy sooner (which is more likely!).

-Randy

Randy

That .dat file is not delimited. It is a fixed length file. If you know what your doing you can import it into Excel and the ultimately through other software into your GPS.

I do this sort of thing all the time and at one time did the data conversion for a living.

If you need any help when you get the file don't hesitate to let me know and we will get it done.