Hi Duane,

 

I'm sure you know this, but just in case, I should clarify that the Chelton systems have three separate databases:

 

1.  Navigation data, such as airport info and instrument approaches.

 

2.  Obstacle data, such as towers and antennas.

 

3.  Terrain data, such as mountains and valleys.  It does not include obstacles like towers or buildings.

 

Most Chelton users I know regularly update the navigation and obstacle databases only, which come out every 28 days.  Since basic terrain doesn't change much, unless you're flying very close to Mt. St. Helens, even an old terrain database is probably adequate, since the earth doesn't move that much in a decade or two.  Since the terrain database is too large to fit on a memory card, I'm still flying with the original one that came with my Cheltons over five years ago.

 

Dennis

Legacy, approaching 400 hours tach time